I cannot read the schedule. Yeah, that's problematic. Anyway, I was fixing the LTE network here at the event, so hopefully it's all working now. Now, yeah, slight little bit of background about myself. I've been working on free and open source software and open source hardware for more than 20 years now. I used to do Linux kernel work, but that's a long time ago now. And I also did a bit of enforcement of the new general public license. But during the last decade, I'm primarily involved in various projects around open source mobile communications. And as part of that work, we see lots of people who also want to play, of course, with the Osmo Comp stack or with other software that works with software-defined radio. And we see lots of problems. And I thought I'll try to make a summary talk on what the limitations are and what the problems are to make sure people don't always fall into the same traps. So, first of all, software-defined radio. Well, lots of people will associate that term primarily with certain devices that are used in the hacker and IT security and research communities. But in reality, actually, almost all radios today are software-defined radios. And that's why I'm talking about so-called general-purpose software-defined radios, where the non-general-purpose SDR devices, for example, are your mobile phones. I mean, they internally use the concept of software-defined radio, but they don't expose the capabilities of that concept to the user. To you, it doesn't matter whether it's implemented in hardware or in software or in some combination thereof. It's a black box and you cannot really modify it in any reasonable way. And most of the software-defined radio devices that are not general-purpose, such as phones or DVB receivers or, as I said, virtually any radio, performs those essential signaling processing steps in software. That's why it's called software-defined radio, but that happens inside DSP cores, typically inside FPGAs, most often with proprietary bitstream or firmware. And then on the other hand, we have the so-called, or I call them general-purpose SDR boards, where you basically have some device that doesn't do much more than the up and down conversion from radio frequency and the analog digital conversion using ADC or DAC in hardware, and then you get baseband samples into your PC or whatever general-purpose computer, typically x86 or ARM devices these days, and you do all the software processing in the general-purpose software on the general-purpose CPU without the use of DSPs or anything like that. So, having said the terminology, if we look at a number of key projects related to general-purpose and software-defined radio, well, I would start it with in 2001 when GNU Radio was founded, launched by Eric Blossom at the time with a very generous grant or donation by John Gilmore to create a software suit, which is very popular even until today, even more so today, to use general-purpose software-defined radio devices. In 2004, Matt Atos, who is here with us at the camp, launched the first USRP device, the Universal Software Radio Peripheral, and then you can see in the last 10 years or seven years or so, lots of new devices or software that enables devices has been published. Many people will have heard about RTL-SDR devices, which is basically a USB DVB dongle, which can be used to not do the actual digital video broadcast demodulation in hardware, but simply stream you samples into the PC and you can use them to receive signals. Companies like Nuand have launched Blade RF by Kickstarter. Michael Osman, very well-known in this community, launched the Hacker F1 in 2014 and for example, 2017 fairly recently, Lyme Micro has launched the Lyme SDR device, the first one in crowd supply, and so on. So we have lots of projects in that area, some proprietary, some open hardware, free software projects, and the related tools have been more available and more accessible, which is great because it means everyone can play with the technology, the very low cost devices like RTL-SDR allow you typically to only receive, whereas more higher cost devices have receive and transmit capabilities, and a lot of people from IT security or pure software or networking background have looked at SDR devices in various different ways, and the leaning curve is still rather steep, unfortunately, if you don't have any RFR electronics background, there's quite a number of free and open source projects around, whether related or unrelated to GNU radio. Unfortunately, not many of them are very easy to use and there's still many, many, many different protocol systems, technologies, radio technologies which are without any or with highly incomplete free and open source software, so that's sort of the status quo, and now we will look at actually the details of what those limitations are that I've put at the title. So, yeah, it's great that all of this is accessible, and as I said, in reality, unfortunately, some people have misconceptions about the complexity involved, and if you think, or if somebody thinks that buying a random SDR and installing some free and open source software will enable you to run a cellular base station, for example, then, well, it's unfortunately not that simple, I wish it were, but in reality it's not, and it's particularly not the case if you're interested in cellular technologies such as GSM, GPR, UMTS, LTE, 5G, GNU radio, any of that. And why is that the case? Well, there's many different topics. I'm going to start with the topic around clocks, several different topics related to clocks. The cellular standards all have very strict requirements on the precision of the carrier clock. So, if a base station is to transmit on a certain frequency, then it has to transmit on that frequency to a very high degree of accuracy. Typical requirements in this area are about 30 parts per billion, and that's unfortunately about a factor of 1,000 off the accuracy that the normal crystal oscillators or the normal crystals have that you find in inexpensive devices. So, a normal crystal may have 20 ppm parts per million, whereas the requirement actually says something like 30 or 50 parts per billion. Some devices have so-called TCXOs that's temperature compensated crystal oscillators, which then have around 280 ppb stability, which is nice. It's much closer to what the spec says, but still it's a factor of 10 or something like that off. And having a clock that's off means all kinds of strange effects. The most commonly known one is that phones may not detect your network, even though it's broadcasting or it may not reliable detect the network, or they may even drop off the network, though the last part is less likely. And this is the number one problem that we see when people play with cellular technology with SDRs. They see some unreliable behavior or they cannot make it work at all. And the number one question is, well, do you have a proper clock? And if the answer is no, then basically it's sad to say, but one can stop even trying to assist or to help at that point because there's so many problems that can follow as a result of that. So that's the accuracy of the clock. The next point is stability of the clock because calibrating the clock once to be precise, to be calibrated is nice, but then the clock's drift, that's due to temperature, to aging, all kinds of effects. And that means you would need to calibrate the clock against a proper reference quite frequently because it depends on how stable the clock is from that point of calibration to a point in the future, how quickly it drifts from that calibration point. And in receive-only use cases where you're just receiving some signal, you can basically do all that with some fancy math and post-processing. You have to track the carrier clock anyway and you have to make the window a bit wider to follow that, that's fine. But it also only works because the transmitters typically are required to be highly precise. So the receiver clock can drift, but the transmitter at least is known at a fixed frequency. But as soon as you start to transmit, particularly in the cellular area, you need this high-precision clock as precision and stability. Another aspect about clocks is phase noise, which translates into jitter in the digital domain. And it's a problem because the phase noise can distort basically any part of the signal. And in some devices, that's even a problem where there's no proper or no decent PLL loop filtering after the reference clock that you feed into a device. And then basically your sample offsets, when you sample the signal from the analog to the digital domain, it's required that your sample times are in precisely equal distant points in time, so that the digital representation of the signal actually represents the analog signal. But if your sample times are jittering around, then you get completely bogus results and all kinds of mess in your signal. So there's some devices that we have seen that are more exposed to this, such as the LIME-SDR mini, which doesn't really have an external clock input anywhere you have to solder it and change a resistor and put, I think, a UFL socket on it and so on, so it's maybe not the intended use case. Options, what kind of options do you have to fix this? Well, you can go for so-called OCXOs, that's an ovenized crystal oscillator. Ovenized means basically you put a crystal in some enclosure and you heat that to a defined temperature inside of the enclosure and you have thermal insulation to the outside of the enclosure. So the point being that if your room temperature and your environment temperature changes, the crystal inside stays at a constant or almost constant temperature and thereby you can basically avoid all the temperature-related drift of oscillators. And good OCXOs, it's sufficient to calibrate them once every six to 12 months and then you can run with stable frequencies. That's nice, but still you need to recalibrate and yeah, so an option that's relatively inexpensive that many people use is the GPS Discipline Oscillators. The GPS Discipline Oscillator basically has an oscillator that can be an OCXO or a VCTCXO, that's a Voltage Control Temperature Compensated Crystal Oscillator, which is disciplined or steered by the clock reference that is derived from the GPS signal. You can do that also with other satellite navigation systems. They're also receivers that can do it with Galileo or GLONASS or something. Well Galileo had some trouble this year, but most commonly it's the GPS DO that people use. And that's extremely stable, but of course it requires you to have permanent GPS antennas, which may be inconvenient if you don't, you're not near a window or something like that. And it also requires permanent GPS coverage and what if people are jamming it or your antenna is broken or depends on your environment and your circumstances, whether that's a choice. The more exotic choices are then Rubidium Oscillators, which are very stable, much longer stable than OCXOs. You don't need any external references. They're rather large and power-hungry devices. And you can find them relatively inexpensive secondhand on eBay or ham radio circles. But yeah, it's bulky, power-consuming, large, not really something that you would want to carry around. A fancy option are so-called chip-scale atomic clocks. They exist, but they're too expensive for most use cases, even in professional sphere. So not really something for the general hacker playing with SDR. It's also important that there are some parameters so that the reference clock must fulfill in order to be compatible with your device. The most important part is the frequency. Well, they're actually all important, but the frequency is sometimes problematic, especially if you have a zoo of different SDRs. Like I have someone to 10 megahertz reference, others one to 30.72 megahertz reference, some others one to 14 megahertz reference. I'm sure there are other reference frequencies that they want. And so you cannot just buy a single GPSDO that outputs a single frequency, but then you may need some other devices that can actually have some PLLs that can actually generate the frequency that you need from the frequency that your GPSDO generates. Another question is whether you need a sine or square wave that depends on the clock input of the device. Some can, well, typically if the device accepts a sine wave and you have a square wave, it's rather easy. You just need a low pass filter and then the sine wave is everything that remains. But if it's the other way around, then it's problematic. So if the device wants a square wave input and you only have an oscillator that provides sine wave, then you need a special device to convert from sine to square with as little jitter as possible because that, again, the jitter causes your problems. And last but not least, the voltage must match. Also, something that you have to keep in mind, almost, well, actually all SDRs that I have worked with require you to actively select the external reference frequency input. It's not sufficient to just connect it, but it needs to be selected and that selection typically is some parameter that might not be easily exposed and you might have to teach whatever application that you're using to pass this parameter down through the driver chain into the hardware so that actually the external reference is selected and used. Some devices provide the luxury of having an LED next to the input to indicate you that this is the clock input now active, but unfortunately it's not yet industry standard to do so. One important factor also to consider if you want to work with cellular technologies, almost all of them require full duplex operation. Full duplex means receive and transmit must be active at the same time, simultaneously on different frequencies. And that, yeah, well, it's sort of obvious, but it means that, for example, you cannot use the HackRF as a GSM-based station or as an LTE-based station because it's not a full duplex device. It's only capable of either receiving or transmitting. And then some people say, oh, why cannot I combine two of them? Yeah, in theory, but then we have some other requirements that we will look into later which require that both of them are synchronized to a large extent. And yes, in theory, you can do that, but I think by the time you're done with making that successful, you won't have any time to actually work with what you originally wanted to do. One other important requirement when it comes to SDRs is time-stamped commands or time-stamped transmit or receive. And that means that it's not sufficient that you can just, you know, you create some samples on your PC and you stream them out over the radio, but you actually want to precisely define at which particular point in time a given sample or which represents the start of a burst is transmitted over the radio. And vice versa, if you receive signals, it's very important to know the precise time at which a certain sample or the first sample of a block of samples has been received because that is important information. For example, in GSM and LTE, that information determines, among other things, from which phone that is actually transmitted because there is time division multiple access happening. So it's important to have this functionality. And despite the fact that many people want to play with cellular technologies in SDRs, it's unfortunately still not a standard feature when new products are introduced. So quite often when new devices come on the market, they lack this functionality so you cannot use them at all with cellular technology. And that needs support basically across the chain from the SDR hardware to the gateware or whatever runs on the FPGA that's in the device. If there is one to the firmware of the device, the host software and the driver stack everywhere, these timestamps need to be passed around back and forth in both receive and transmit side. And you also need sync between Rx and Tx, which means that you need to be able to relate the clocking of the receive and transmit samples. And you need to know that a certain moment in time represents the receive signal at the antenna input and not the receive input at your ADC. So you have your antenna input and then you have some low noise amplifiers or whatever kinds of blocks, even PCB traces, which all causes delays in the signal propagation. So you actually have a delay between when your ADC, sorry, your DAC is outputting an analog signal until it appears at the antenna interface and vice versa, a delay between when the received signal hits the antenna and until it is actually digitized by your ADC. And those delays need to be measured and you need to know them and your software needs to know about them because the software needs to compensate for those analog delays. And these values are different from every board, not every unit of a given device, but let's say if you have a USRP2 or USRP1 or a USRPB200 or a LIME-SDR, each of those boards or products has a different value that needs to be measured and which the software needs to know to compensate for this analog delay that's in the signal chain. And if you attach additional external devices, then actually that also needs to be compensated for in order to be compliant with the required specifications. And sometimes that's sort of a bit of a problem because new products try to emulate all driver interfaces. So let's say a new product comes on the market and it's compatible with the driver infrastructure that existing products had. But then of course, the compensation value or this delay value that you use is not known yet. So the value for another board is used and that of course is wrong at that point until somebody actually sits down and measures that delay and sends a patch for the software and so on. Which brings us to the topic of vendor drivers where if you're buying a general purpose SDR, what you're buying or obtaining must not be buying, but in any way you're getting not just hardware, but of course, lots of software, software that runs on your host PC, software that runs in the FPGA, in the gateway, in the controller, whether it's a microcontroller or a soft core on the device. And all that software, unfortunately, often at least initially has a quality that may be much worse than the hardware quality and then lots of vendors have their own, well actually every vendor I would say have their own different driver stack and APIs to talk to the SDRs. And the APIs often are not stable across releases. So every couple of months something breaks subtly in the APIs, which doesn't make things easier. So that means that software in general needs to support all those different drivers and follow up with all the changes that they introduce in the interfaces. It's not particularly nice. And unfortunately, there's also non-technical reasons. In this case, I think one of the well-known examples is that the UHD driver stack, which was the universal host driver or USRP host driver originally, is maintained by Atos Labs, which is now part of native instruments. And they won't merge drivers for competitors. So if somebody else produces a product, I mean, this is an open source project, UHD, right? But in the official tree, they will not merge drivers for other products from other vendors, which I think is unheard of if you look at other software projects. I mean, as I said, I have a bit of a Linux kernel background and I've never heard that somebody who is maintaining a given kernel subsystem and might be on Intel's payroll is refusing to merge drivers that are produced by AMD or made for AMD hardware. So I think it's quite a bit of a strange attitude in the context of free software here. Of course, somebody could just come around and fork it and merge all those drivers. But yeah, there are forks, but everybody has their own fork. And then you have additional layers like SoapySDR, which try to unify all these different APIs. But then the stack gets deeper and you have another layer of abstraction and the layer of abstraction might make it more difficult to control some aspects of the hardware. So yes, it's good, but it all has its positive and negative sides. And sometimes one thinks the world could be much simpler and in other areas of software development, I think there has been more standardization on common APIs and common interfaces rather than everyone rolling their own and all these compatibility issues. Another important topic is related to so-called overruns and underruns. So in the end, what you have is that when you run an SDR is the transmit side expects a continuous stream of samples to be transmitted and the receive side generates a continuous stream of samples that are received. And your entire system, hardware, software, peripherals, whatever needs to be capable of sustaining that at any time. So every time one component, whether it's a software or hardware component, is not capable of consuming or producing the samples in time, you get dropouts leading to buffer underruns, buffer overruns. You may know that from audio related work, maybe not today with today's computers, but if you've been around 10, 15, 20 years ago and you were playing with digital audio on PCs, then you may know some of those problems that you get overruns and underruns and the speed is not sufficient to keep up with the real-time requirements of such use cases. Well, that was audio with, let's say, 44 kilohertz of a sampling frequency. Now we're talking about SDR. We're talking about mega samples. So we are talking about millions of samples that need to be processed. So the requirements are much stricter and much more demanding. And all of these different devices, they all have buffers because they're not really designed for continuous streaming of transfer. And those buffers, then again, a buffer containing 100 samples means your stuff gets delayed by 100 samples. So you introduce latencies and the aggregate number of buffers you have all over your software and hardware stack determines what kind of systems you can implement because some of them may have rather strong requirements on what the maximum latency must be between receiving something and transmitting something that depends on whatever you have received before. So you cannot implement a 3G base station, for example, a real one with an SDR that's attached over USB because USB is just the latency is way too high. You can never do the timings. And even for LTE, it's actually rather amazing what projects like SRS LTE are doing that they can do this within the string and requirements of LTE despite wasting so much time of moving data over USB back and forth. One thing that can help a little bit is using real-time scheduler priorities, get RR on Linux. And you also have to pay a lot of attention to dynamic power management systems which may change your CPU speed and frequency and so on at runtime. So better disable all these things if you want to have a reliable operation with an SDR-based system. And also we see problems from biases sometimes where you know, let's say you attach an external screen and then some system management code on an X86 box tries to do something and meanwhile you're dropping millions of samples, right? Or you put your system into a docking station or you attach a power supply and then something happens in the deep down in system management mode that interrupts your normal processing and again, some samples are gone and you get overruns and underruns. Another topic to look into is the transmit gain settings because well, thinking an SDR is just an ADC and the DAC is too simplistic. Of course, you have all kinds of analog components next to it. And that's the up-down converter and you have maybe some filters or whatever and you have gain stages. So in the transmit side you convert from digital to analog and then you have different gain stages and all those gain stages you can configure normally from software. And you need to configure all those gain stages properly in a way that they operate with linear characteristics and they don't distort the signal because if you have a too high signal at the input of the next stage you will get clipping or all kinds of weird effects and that distorts the signal, introduces harmonics, introduces out-of-band interference that you then start to broadcast. And so you need to basically twiddle all these settings again for each and every SDR device that you want to support from software and basically tune all those settings manually until the signal looks best and you hit a sweet spot where the signal looks best and with some devices you may not get to the point of the signal ever looking the way how a professional measurement device for the given telecommunication system would actually expect a signal to look like. And then of course all of those settings about the gain stages, they depend on the frequency and or the band in which you operate. So you've tuned all those parameters and figured them out correctly and then you change the frequency and you start again to fiddle with all those buttons in order to get all of them set up properly. Which brings us to other things on the transmit side which is the power level. So a normal general purpose SDR device typically outputs only what's zero DBM, maybe four DBM, 10 DBM, that's very little power which is good if you just do lab testing on a desk but if you actually want to do real operation then of course you need some kind of amplification. Simply needs to be amplified. So while you go on eBay and you find lots of inexpensive power amplifiers for the band that you're looking at and so why is that not a good idea? Well the output signal of the SDR already contains normally quite a significant amount of harmonics that's basically twice, thrice, four times and so on the frequency of that you're transmitting and if you just put an amplifier behind that the amplifier will transmit, will amplify also all those harmonics. So you normally want to put proper filtering before and if necessary also after the amplifier so you then have your SDR and already three additional blocks on your desk and the clock and so on. And then actually it's more complicated than that because an amplifier is not in general a linear part meaning it does not amplify any signal the same way like another signal or part of your signal. And then particularly the more affordable amplifiers are not so linear and they're trade offs between power consumption and linearity so you can build highly linear amplifiers that consumes tons of power or which then means you need to cool them and so on or you can have less linear amplifiers and particularly signals that have a high peak average peak to average power ratio that means they change the amplitude while transmitting get distorted a lot by non-linearities in the amplifier and if you look at commercial base stations that actually implement all these systems you have what's called digital adaptive pre-distortion to compensate for the non-linearities. So basically you output a signal you put it in your amplifier and then you digitize that again from the analog into the digital domain you measure what's the difference between my intended signal and the actual signal at the output of the amplifier and then you do all kinds of math to pre-distort your actual digital signal before you convert to analog and feed it into the amplifier and you do that as a continuous loop because all of that of course depends on temperature and aging and all kinds of other nice effects. And I've heard, I mean I'm not involved in those kind of projects but I've heard several times that at least a couple of years ago several times that the pre-distortion actually is more computationally complex than the system that they implement in the first place. So there's a lot of math that goes into this pre-distortion in order to have proper signal at the end of the amplifier. So yes you can use an amplifier for very simple waveforms for constant envelope things like GSM for example but if you wanted to LTE or something like that you need a very linear amplifier. Yeah, then the next topic is that the level somehow normally should be calibrated because well an SDR doesn't give you a defined output, right? You have your analog digital converter and you can output from let's say zero to whatever 4096 if it's a 12-bit DAC and that's your basically your scale but you don't really know to what that corresponds in terms of an absolute output power at the end of your board on a socket. And then again if you change the frequency your output level will be different. So basically on the digital domain you do everything the same but then you change the frequency and your output power level changes because again there are non-linearities in all these parts and unlike base station hardware or other professional radio hardware that's purpose built for a certain purpose the general purpose SDR boards are not calibrated or don't come with calibration tables. The vendors could do that but it's a lot of effort to calibrate those units and ship calibration tables so they don't. So you don't have any absolute value and the absence of known absolute values means you don't actually know how much you transmit at any given point in time which means that you create problems if you really want to operate let's say a cellular network with that because if you don't know how much how strong you transmit you may create interference you cannot really do proper network planning and so on. And I have to catch up a bit in terms of time. So on the receive side we also have harmonics not just on the transmit side and that basically means well your SDR fronted is an open mixer and let's say you want to receive 900 megahertz but it unintentionally will also receive 1800 megahertz because that's you know twice the amount and that's the first harmonic. So you need to put filtering on the analog side otherwise you will receive all kinds of things that you don't want to receive so you need an analog band filter between the antenna and your RX input and ideally that band filter should only cover the band of interest and should filter out everything else outside of the band. Next topic which is related to that is the dynamic range on the receive side because again your SDR front end is a wide open receiver and any energy that is present at the input of the receiver whether it's near or far will pass at least to the first stage LNA that's the first amplifier in the receive chain and then may propagate even to the mixer input depending on the detailed layout of the device or the chip and then possibly even further down to the ADC and any energy that is outside the signal that you're interested in is just going to create a problem for you particularly if it's a strong signal because a strong signal means that it might clip and clipping means distortion and distortions means you won't receive anything useful and in the end then basically your all the entire receive gain chain must be tuned to accommodate the highest signal that you receive the strongest signal you receive even if it's a signal you're completely not interested in let's say you want to receive GSM but there's an FM station nearby an FM transmitter you might have that FM signal in there unless you have filtering before your SGL device at the input otherwise that might saturate your LNA and basically you lose all the sensitivity and all the dynamic range and then also on the receive side you want to know absolute power levels in cellular systems they're specified to use receivers that are calibrated that tell you exactly well exactly roughly plus minus 2 dB is actually a very large tolerance it's not a measurement device right meaning that a received signal receives with a certain value and that receive signal level in turn will be input to power control loops which tells the phone how much to increase or decrease the transmit strength to be received at the proper level but if you receive level it's not calibrated and it's just some random guess or some arbitrary value that's not calibrated to anything like such and such amount of dBs of full scale but yeah how do I convert it to an absolute value you cannot unless you calibrate the device so again you have trouble there which brings me to the end so I'm sorry to rant about so many topics I'm not saying that people should not play with SDR to the contrary it's very exciting technology and everybody should be working with SDRs but you have to understand the limitations of the system you're working with if you want to have proper results and it's not as easy as just getting a general purpose SDR device from whatever vendor and then playing with software if you don't have other accessories like let's say a proper clock source or a spectrum analyzer to actually look at what you're outputting or some other tools and like filters and so on LONOS amplifiers maybe power amplifiers antennas, splitters, attenuators so it's much more likely that you will end up collecting an entire zoo of devices and accessories so the SDR board may be the start but it's unlikely to be the end of working with SDR devices so be prepared that there is other things that you may need to obtain beyond the SDR board and as I said it's important to understand those limitations and to make sure that at least the most common error sources are excluded before trying to debug systems that have seven more layers of stack on top of them and something doesn't work and you have no idea what's actually the cause if your layer zero is not even behaving properly so yeah that was basically what I wanted to present I hope it wasn't too boring and I hope there will be some questions or challenges or contradicting statements or whatever else so thank you I'm very impressed do we have any questions from the audience hang on I'm gonna do this again here we are remember one sentence no comments just a question so I assume that the cellular phones don't have very accurate clocks so if the transmitter basically why does the transmitter need an accurate clock if the receiver doesn't because if the transmitter is off wouldn't that be equivalent to the receiver being off so in short the transmitter must be accurate so that the phones don't have to be accurate because the phones calibrate the receiver or the calibrate their internal clock to a reference signal that is specifically crafted in the transmitted waveform from the base station so they can calibrate their clock to what the transmitter is sending now you may or may or may not know that but now the problem is yeah well part of your question why is it then important that the transmitter is accurate well the problem is the transmitter is not the only transmitter on the on in your coverage area normally it's transmitting so you have multiple of them and the phone clocks it's internal or calibrates its internal clock against the first signal it sees and that for example means if you have a base station on your lab desk which has a wrong clock but you have a real network with a proper clock like a commercial network around you switch your phone on it sees the by coincidence or by whatever it sees the commercial network first it locks it's it calibrates its internal clock to something derived from the commercial network and then it will no longer see any other transmitter that doesn't have an accurate clock and then they have exactly that effect you operate everything the signal is there you may even see it in a spectrum analyzer but your phones don't even see list the network because it's not at a frequency that they can understand I have a question about computational power asking because I don't know are you aware of the Pluto SDR little cheap device with a zinc processor if you get the clock figured out the analog chain in front of it do you think it would be computationally feasible to do LTE with such a device or is that way off? Well the clock I just heard I always complained about the Pluto SDR not having an external clock input but I just heard like 10 minutes before this talk that it's actually one that just didn't expose it on the socket so if you open it there is like a socket or something where you can put a reference clock into several reasons why right now you cannot do LTE with the Pluto SDR and the prime well I would say personally the first reason why it doesn't work is because the entire driver infrastructure that this device uses does not do any form of time stamping neither on TEX or RX so I think it's primarily a bad choice of software architecture that constrains it in that way I mean there may be other restrictions but that alone is the reason but I think it can be fixed Is there a question wait a minute you'll be right there is there a question from the internet do we have a question from the internet? I'm sorry but no No, okay your question please just one sentence no comment Well it's very difficult to not comment very good good talk thank you very complete as well and also very dense information but what I did miss group delay a few things antennas and VSWR yeah that's correct I mean for sure it can be expanded in other topics thanks for that maybe we can do a workshop or something on those topics if somebody's interested so which steps would be required to build a full duplex capable SDR of two radio batches to be honest I cannot respond immediately I would have to check the schematics again I think at the very least I mean you would have to start of clocking them of the same reference and then yeah well yeah I don't want to try to make an answer without looking at the facts but I think I mean people have shown that things like this can be done as a proof of concept but yeah it's it's a lot of effort and a lot of hackery and yeah I mean you can just use a proper device instead rather than spending a lot of time solving a problem that other people have already solved but yeah that's my opinion hi Arl do you have any recommendation on where to find the filters because I remember I searched on ebay but they are rather rare or expensive any recommendation it depends a bit on what kind of bands if you work with cellular bands most often you can actually find the filters that are used in the phones themselves they are surface acoustic wave filters saw filters and you can typically find them on ebay and other component distributors the problem is they come in such small packages that you need rather how can I say good SMD soldering skills and then also sometimes the problem is that they might not have 50 ohm matching but some you know 100 ohm symmetric or something like that so some balloon or some whatever might be needed to use it in a 50 ohm system and for the transmit side if you have real power then the only real option at the frequencies in the cellular domain is to use cavity filters or cavity duplexers and yeah there are some sources but I don't want to make advertisements here in this talk can contact me privately two more questions please two more only one question one sentence yeah so first thank you for the great introduction so from experience I know that rubidium clocks have terrible face jitter did you ever try rubidium clocks and if you did so what did you do to clean them up to be honest I don't use a rubidium clock I bought one once because it was so cheap but I never really used it so far so yeah I have a GPS discipline I have an OCXO that's this GPS discipline so it can run for quite some time even without a lock and that's what I use in my setup and I have some 10 megahertz distribution in my lab via coaxial wire so that I can attach devices to the reference at different locations different desks okay thank you for a good talk you said calibration of the boards is a hard problem are there good enough sets for each kind of board that we have and if not is it maybe a business opportunity to help people calibrate their SDRs okay so the question is about what kind of calibration are we talking is it the receive and transmit signal strengths I don't really know what the whether it would be sufficient to create let's say one set of default calibration and then assume that more or less most of the products are in in the same range I don't know what the spread is for those SDRs I think only the excuse me only the manufacturers would know if they ever checked about what the spread is I think I wouldn't think if in terms of business opportunity but I think there's a large opportunity for an open source project that can help many SDR users is to basically design software and describe a hardware setup using which you can do all these calibrations in a fairly automated way with any SDR virtually as the device under test and then that could be something that hackerspaces for example could operate to help other people calibrate their devices thank you okay one last question if you had one no okay that is thank you thank you very much Jordy


Lux presents Hollywood radio theater brings you Fred McMurray and Marguerite Chapman in Pardon My Past. Ladies and gentlemen your producer Mr. William Keely. Greetings from Hollywood ladies and gentlemen. One of the fastest growing elements of our population is the lowly mink. With care and patience you can raise a couple of these 24 inch rodents into something glamorous and beautiful.  I mention these facts because they motivate tonight's play. Columbia Pictures recent comedy release Pardon My Past starring Fred McMurray as the boy with a future in mink and Marguerite Chapman as the girl with a mink in her future. Who gets fleeced in this story of the old skin game you'll shortly hear. But first I'd like to thank Virginia Maxwell for a different kind of story. As a member of the Red Cross she was present at a dance in China given to promote Chinese-American relations and attended by dignitaries of both countries. The high spot of the program was the presentation of three valuable door prizes. A lovely piece of carved jade, an exquisite heirloom teapot over 200 years old, and luck soap. Chinese guests won all the prizes and while the Americans were politely envious they were also proud that an American beauty aide like luck's toilet soap should rank so high in foreign estimation. Here's Act One of Pardon My Past starring Fred McMurray as Eddie York and Marguerite Chapman as Joan. It's a fine spring afternoon in New York City. In his lavish Madison Avenue apartment Mr. Elias Arnold has just received two visitors. Behind the visitor stands a rather sinister gentleman, a gun in his hand. You may dispense with your firearm Mr. Locke. I am sure Mr. Pemberton here and his friend will prove very reasonable. Okay, Mr. Arnold. Mr. Pemberton, how good to see you again. I tell you my name isn't Pemberton, it's York, Eddie York. Yeah, and I'm Chuck Gibson. You got us mixed up with somebody else. Don't holler at Mr. Arnold. Understand? What is this nonsense, Mr. Locke? You got me, Mr. Arnold. I've seen him walk in the append station, see? I says hello, Mr. Pemberton. And what happens? He gives me that Eddie York stuff. Ah, leaving town again, eh? A lot of stuff about going to Wisconsin to race me. That's right. I don't know what this is all about, but you've made us miss our train. We're supposed to be on our way to Beaver Dam, Wisconsin. We bought a mink ranch, see? And my name is not Pemberton and it's York, Eddie York. All the way here, that's all he says. Your name is Pemberton, Francis Pemberton. And two years ago you placed a bet with me for $12,000 on Pegasus in the sixth race with Hialeah. Since then, you have been a trifle difficult to locate. Eddie, the guy's a bookmaker. I have many hobbies, Mr. Gibson. Making book is one. Collecting books is another. Look about you. You see the volumes on my shelves? Everyone a first edition. It cost a great deal of money to be a bibliophile. Oh, what he said. And that is why at this high time you pay your debt, Mr. Pemberton. Here, here I'll show you. We just got out of the army, see? Here's my discharge card. There, you see? Edward L. York. That's me. Ah, don't think you would go to these lengths. Let me have that wallet. Hey, that's my money. Yeah, our money. Have that bank roll as mine. Not more than $3,000. I'll credit it to your car. Now wait a minute. No. Mr. Pemberton, here you are, a young man with everything to live for. Actually risking your life to cheat me out of money you wouldn't even miss. Wouldn't miss? It's every cent I got in the world. We got. I shall call tomorrow morning for the remaining $9,000 and please have a threat. I simply cannot bear the idea of live people owing me money. It makes me nervous. Mr. Long, you may drive them to where you pick them up. We'll be back. We'll get the cops. Don't use that word. Mr. Arnold, don't like. Till tomorrow morning, gentlemen. Long guy, Eddie. Now what do we do? What do we do? We go straight to the police and tell them that Chuck, Chuck, did you get the address where that Arnold guy lives? No. Oh, fine. Did you get the license number to car? No. Couple of smart boys. Hey, wait a minute. There's a cop. Hey, Hey, officer. What's the matter? Hey, officer, my friend and I here were walking down this street a little while ago. I'm glad to see you're back and sober too. Well, well, officer, I'm not Mr. Pemberton. I, I never mind. You want some trouble? No, no, no. Well, it's nice to have seen you again. Thanks. Thanks very much. Hey, Eddie, I'm beginning to think maybe you still look like this guy, Pemberton. No. Yeah. Hey, Chuck, Chuck, I've got an idea. Oh, it's about time. Look, all we got to do is find this guy, Pemberton, explain what happened, get our money and we're on our way. Right. A telephone book. All we got to do is look him up in the telephone book. Oh, this ain't no mean look in Chateau, brother. Are you sure it's the right place? Yeah, that's what it said in the phone book. It's better be. They wasn't kidding when they named this Long Island. Oh, we want to see Mr. Pemberton. Why, Mr. Pemberton, good evening, sir. And we go again. My, this is a surprise. There's a fire in the library, Mr. Pemberton. I'll tell the rest of the family you're home. Oh, whiskey, sir. No, no, thanks. I'll have a double. Very good, sir. I got a hunch I'm going to need it. Yeah. Hey, Chuck, if the butler thinks I'm Pemberton, it's pretty clear the real Pemberton isn't here. What do we do now? Oh, maybe he's got a rich hand or something. We ought to be able to get 3,000 bucks out of somebody around here. Hey, Chuck, look, this picture on the desk here. Uh, to Joan, it says to Joan, my good right arm, Francis. And I wonder that book he collar to assist guy in the picture.   Thanks. Well, you might have written it or something. How was Mexico? Mexico? Well, look, I, I want to apologize for barging in like this. Well, it's your home. Oh, Francis never remembers to introduce anyone. Mr. Gibson, just call me Chuck. Good. You can call me Joan. Are you saying Chuck? Well, Chuck's just staying until the, well, he's just staying until I can pay him some money. I owe him. Yeah. You see, I'm crazy about links. And I was going to buy a farm just as soon as I got three grand out of bed. Hey, Francis. Your luck is running through the form, Francis. Why don't you write him a check? Right. Well, I would only. Well, well, Chuck wants the cash, don't you, Chuck? Yeah, there's something about good old hard cash, I guess. There might be that much in the safe. In the safe? Well, Joan, look, I'm awfully tired. Would you just run to the safe and get $3,000 out and give it to Chuck and then we'd be all square, huh, Jeff? And how? You'll have to give me the combination, Francis. The combination? You know, it's silly, but it doesn't seem possible, but I just can't seem to remember it. Well, Uncle Wills can give it to you. Oh, that's right. I forgot about Uncle Wills. I'm sure you'll be home in the morning. In the morning. I wonder what happened to that Frank? Oh, was that your, I told Bert's not to bother. I thought it was for Francis. I'll have it brought right in. At the same time, I'll speak to the housekeeper about your room. Look like they got you pegged for kind of an elbow bend, my friend. Yeah, Chuck, look, we got to get out of here. Just when we're all set to get our $3,000 next. I wonder who that girl was. That's Joan, her name is Joan. I know that, but I mean, what does she do around here? What's the difference? What's the difference? Well, what if she's my wife or something? No, no, Chuck, I can't stay here.  No, but... And unless we squat here until we get it, we whistle for our three grand, don't we? Yeah, I guess. Then what's the matter with your noodle? Tell me that. Did you notice if she was wearing a wedding ring? Well, well, well. Oh, good evening. Not back to stay, I hope. Your drink, sir. But they do run you out of Mexico. Well, here's to you, pop. Ain't you having one? No. You ain't? Well, well. I see you're still picking your friends from the Bowery. Oh, yo, it's old man. I could sue you for that. I'm just his grandpa. Now, grandpa, don't mind him, Francis. You know how he is. Doesn't mean half what he says. Why don't you open the window and throw the old cockroach out to the petonias? Him? If he'd do that, I'd think there was some hope for him. And I suppose I'll see you in the morning, Francis, or maybe I'll be lucky and oversleep. If you'll come upstairs, Chuck, I'll show you to your room. Good night, Francis. Night. You're not going to bed, Francis? No, no, no, I just think I'll sit here and think a while. Think? You mean get drunk? Please, Francis, not on your first night home.  Yeah, many objections, grandpa. You sober? Certainly I'm sober. What are you so mad about? What have I done? Nothing, as usual. The point is, what are you going to do? About what? About what? Young man, there's a little lady upstairs.  She has? Yes, she has. Now, you march right up there and do something about it. She's waiting for you now. Chuck. Chuck, which room are you in? Hey, Chuck, where are you? Oh. Oh, hello. Did I hear you come up and calling someone, Francis? No, no, no, it's really nothing important. Then come on in. Oh, no. You're probably busy. Come on in. Grandpa said you wanted to see me. He did? Well, maybe I misunderstood him. Francis, is something bothering you? Joe and you know how it is with a guy like me. Lots of things bothering. They're never used to. Well, I'm different now. I'd like to believe that. Oh, it's true. I'm practically not the same fellow at all. You and you and grandpa seem to think I'm pretty much of a heel, don't you? Oh, I think spoiled would be a better word for it. And a little spineless now and then. Well, I asked for it. Francis, what about Mary? Mary? Yeah, Mary. Well, I was sort of hoping we could forget about Mary. I suppose you'd like to forget about Susan, too. Susan. Don't you even want to see her? Who? Susan, of course. I'll take you in to see her now. You mean she's here, right here in the house? Frost uncle wills to see the bath. The detective wouldn't let her leave. Detective? Why? Is she violent or something? Francis, are you sure you're quite yourself? No, I mean, well, with you here, it's a peculiar sort of setup, isn't it? I'd better not go in tonight. Maybe she's asleep and, well, I'd better look in on Chuck. He might want something. Francis Pemberton, after two years, the least you can do is let her see you. OK. Now, come along. We'll only say a minute. Daddy? Yes, dear. It really is. This is Susan? I don't wonder you hardly recognize her. She's grown so. Well, how are you, Susan? Finally, I don't seem to know you very well. How do I, Daddy? Are you going to live here now? Well, I... I wish you would. I'll let Daddy or let Mommy come to see me at Jones. Daddy just came in to say hello, darling. It's sleepy time now. Well, you let Mommy come to see me, Daddy. Why, uh, why, sure, I guess so. Do you really mean that, Francis?  Tomorrow, Daddy? Tomorrow? Well, yeah, I guess tomorrow would be fine. Well, uh, good night, Susan. Good night, Daddy, and thank you. Sleep tight, darling. There. That's the girl. Good night, Aunt Jones. She called you Aunt Jones? Yes. Well, then she's not, uh, I mean... Well, it's usually the fate of most poor female relations to become aunts, isn't it? Oh. Well, you, uh, you make a very nice aunt. I've tried, too, Francis. Mary's going to be so happy. I'll phone her right away. Mary? Oh, uh, yes, Mary. Francis, I want to take back everything I said. I wouldn't have believed it, but, but you have changed. Something has happened to you, and, and you don't know how good it makes me feel. Good night, Francis. Hey, uh, you kissed me. That was for Susan, and for Mary. But, uh, but... Good night. Will you wake up, Chuck? Come on, come on, I'll get up and get dressed. We can't stay here. What's the matter? You want to throw you out? No, she's not my wife. She's some kind of a relative, though. But I've got a wife. Well, congratulations. No, no, I mean, Pemberton's got a wife. And I'm a father. I mean, Pemberton's a father. Look, Chuck, all the time this Pemberton's been away, he wouldn't let his wife see the kid, or this Uncle Will's wouldn't. And I just said she could. If we don't get out of here right now, we're going to be in the middle of a family reunion. Just a minute.  Yeah, but... Now listen, chughead, the money down in that safe is our money. If you just don't get excited, we'll have it back. We only have to stay in for morning. Yeah, but... All right, move over. In just a moment, we'll bring you the second act of Pardon My Past. Meanwhile, here's our Hollywood reporter, Libby Collins, with news about the stars. Two very lovely stars, Mr. Keely, Captain Grayson and June Allison. I've just seen them both in the title roles of Metro Goldmayer's Two Sisters from Boston. Oh, that's the new musical picture. Yes, with songs for everyone's taste, for musical duties to grand opera. Imagine seeing and hearing Jimmy Durante and Lord Eats Melchior in the same picture. Mm-hmm. And Hanson Peter Lawford for romance. In Two Sisters from Boston, MGM has given Captain Grayson a good opportunity to display her fine color at your voice. She's not only very talented musically, but she's so lovely to look at. One of our prettiest lux girls, wouldn't you say, Libby? Oh, yes, indeed. Katherine's really adorable, especially in close-ups, with her glowing dark eyes and fresh, smooth lux complexion. Another treat is the blonde loveliness of June Allison. Now, there's a famous lux beauty for you, Mr. Kennedy. June Allison and Katherine Grayson. Gosh, Libby, what a recommendation for lux soap when two such lovelies depend on it for beauty care. And they do, Mr. Kennedy. Both those famous stars say they wouldn't be without lux toilet soap for a single day. Well, Libby, Hollywood stars know lux toilet soap is a quality product, a real beauty soap, ripe for delicate skin. Nine out of 10 famous stars use lux toilet soap for their daily complexion care. I think any woman who follows their example will be delighted with the fresh new loveliness active lather facials can give her skin. And in these days of shortages, when everyone is being careful not to waste vital materials, it's good to know lux toilet soap is hard milled, can be used right down to the last thin sliver. Why not try this fine white complexion soap, Hollywood's own beauty soap, tomorrow? Here's Mr. Keely at the microphone. Act two of Pardon My Past, starting Fred McMurray as Eddie York and Marguerite Chapman as Joan. It's early the following morning. In the Pemberton dining room, Grandpa gets up from the breakfast table, walked to the window, and stands gazing out in a state of complete consternation.  Grandpa, what's the matter? What did you say? Look out there, Joan. Francis Pemberton not only up at this hour, but out on the lawn playing with his daughter. He's been up for hours. I had breakfast with him. Liquid or solid? He hasn't had a drink since he came home. There's something wrong here. Maybe we've misjudged him. Say, what kind of a look is that on your face now? See here, Joan, you ain't beginning to get yourself... I ain't beginning anything. And if I were you, the last person I'd tell. It's the spring weather. You better drink some sulfur in the lasses. I beg your pardon. Yes, Bert? Mr. Wills is on the phone, Miss... Oh, Uncle Wills. Thank you, Bert. Oh, tell Mr. Pemberton, will you please? But didn't you ask him for the combination, Joan? I mean, do I have to...? He wouldn't give it to me. Well, pick up the phone, Francis. Well, does Uncle Wills sound mad or anything? What if he is mad? I think it's high time you began standing on your own two feet. Oh, well, it's just that I'd rather... Well, here goes. Hello, Uncle Wills? Wills? Oh. Well, I just forgot to, I guess. What's this nonsense about you wanting to get to the library safe? Well, I just want to get into it, that's all. Well, I'll be right up. Oh, no, no, no. Just give me the combination. Francis, are you sober? Of course I'm sober. Now, look here, Uncle Wills. Are you going to give me the combination, or do I have to come down there and shake it out of you? Well, do you have a pencil? Yes, I have a pencil. Left. Left, 21, right, 10. Left, 7. Left, 7. All right, go on. Well, that's it. Left, right, and left. Oh, OK. Thanks. Francis, do you realize that you actually talked back to him? You were wonderful. I was, huh? Well, uh... Wonderful for you. Oh, uh-huh. Joan, how come you never got married? Well, looking after Susan in the house has kept me pretty busy, you know? Then I guess the right man just never came along. Uh-huh. You, uh, having any commitments at all? No. Why? Oh, I was just thinking that... Well, uh... Well, it's natural that I should be interested in your welfare, isn't it? Well, I, uh... I guess I'd better get that money for Chuck. Yes, I guess you had. Joan, it's been nice meeting you. I mean, meeting you all over again. You know, I almost feel the same way myself, Francis. As if I'm just getting to know you. You like me better this way, huh? Loads better. Well, you'd better get to the safe. Yeah, yeah. I guess I'd better. Well, stop looking so guilty. You remind me of a second story, man, on his way to a window. I do? I don't know why I should look like that. Sorry to interrupt, but Mary's here. Oh, good. Where is she, Grandpa? I'm the patio with Susan. Well, Francis... Huh? Your wife's here. Aren't you going to... Oh, that's right. Mary... Well, I, uh... I'll try and see her later. Francis... Chuck can wait a minute for his money. Now go on outside and see your wife. Oh, okay. You say so. Hello, Francis. Oh, uh... Hello. Francis, you're... You're letting me take Susan. This isn't some kind of a terrible joke, is it? Well, no, no. You can take Susan any time you like. Why, Francis, what's come over you? Why, you even look different. I do? Well, uh... I've been outdoors quite a bit lately. I... Had a lot of fresh air and exercise. That must be it. Oh, no, that isn't it. It's inside. You've changed. Oh. Why didn't you answer my letters? Your letters? Didn't you get them? It doesn't matter. All it matters is that I'm with my baby again. Francis? Oh, yes, Grandpa. That dang fool detective, he's trying to tell me that... A little girl ain't supposed to leave the house, Mr. Pemberton, unless I go along. That's my orders. Well, uh... Now you've got new orders. Okay, Mr. Pemberton. I bet Uncle Will's will sure be mad, Daddy. Don't you worry about Uncle Will's. Francis, you didn't get my letters, did you? No, I, uh... I didn't. What Uncle Will's told you isn't true. Neither was the evidence they brought up in the court. You must believe me. Well, uh... Mary, I... Well... We'd better go along now, Susan. Thank you again for letting me have her. You'll never regret it. Goodbye, Daddy. Uh, goodbye, Susan. Well, son, maybe Lippards don't change their spots, but Doggon, if I ain't seen a polar cat, change his stripes. Uh, well, uh... Uh, grab I, uh... I haven't got time to talk to you now. Don't give me that hanky-panky. Aren't you sure you're the same poisonous scud we used to have around here? Oh, are you sure? I'm sure. Uh, I'll talk to you later. Uh, you're in an awful hurry to get into that safe. Oh, naturally with the... Well, I'm a day late already with Chuck's money. It won't take you long? Well, no, only as long as it takes to open up the safe. That's good, because Uncle Wills is on his way over. Uncle Wills? Just phone. Oh, and that ain't all. A couple of men just drove up to see you. Chuck's talking to him now in the library. I think Bert said that Darkwind's name was Arnold. Arnold! What's the matter? Oh, nothing, Grandpa, nothing. Mr. Arnold just won't believe us. You're quite right, Mr. Gibson. Mr.  Now, open that safe. For the last time, my name is Eddie York. Oh, yes, of course. That's why you spent the night here. That's also why your butler said Mr. Pemberton was in. Well, suppose we have a look at that safe. Oh, wait a minute, Mr. Arnold. Mr. Arnold said he wants you to open it. Uh, better. Open it, Eddie. Well, okay. Left 21. Right 10. Left 7. There. Now then. Oh. Oh. Hey, it's empty. Rather like your head, Mr. Pemberton. Well, this brings us to a rather unpleasant necessity. And who is that ill-mannered individual? That must be Uncle Wills. He brought coming in and out a most annoying household, Mr. Pemberton. Come, Mr. Long. Are you leaving?  But we are not finished, Mr. Pemberton. Francis! Francis! Are you in there? Is that you, Uncle Wills? So, here you are. Hello, Uncle Wills. Who's that fool with you? Does he mean me? I want to talk to you alone.  Well, you're acting rather peculiarly, my boy. Uncle Wills, you said you wanted to talk to me. Well, go ahead and talk. Yeah, we got work to do. You're not well, are you, Francis? You've been drinking. What goes on around here? What do you mean? Well, the detective out at the gate and Susan not being able to see her mother. Well, those were your own instructions. Oh, that's right. Well, now look, Uncle Wills. From now on, Susan can see her mother any time she wants to.  No, I don't. You're not responsible.   Unless you keep the custody of Susan, you'll lose half your entire fortune. I thought it was something like that. Look, sir Gallowhead, what about the 3,000 smackers? Oh, so that's why you came back. Well, you don't think we bust into this quail's cage for fun, do you? You better make a 12,000. We don't want to go through that again, you know. Yeah, you better make a 12. We don't want to go through that. I'll give you a check right now. 12,000 dollars. But on one condition. Uh, what's that? That you go back to Mexico and stay there. Okay. But I want Susan to be able to see her mother. Well, you have my word. Uh, that check you're making out, you're making out cash, aren't you? It's all made out here. I'll have Joan get your reservation on the afternoon play. Goodbye, Francis. The check. Well, let me see the check. Hey, check, this check's no good. I mean, well, look at it. He made it out to Pemberton. Hey, Uncle Wills. Let your four Uncle Wills along. Just endorse it. Endorse it? But I can endorse it, Mr. Arnold. It'd be forgery. I am beginning to understand why people like you are so rich. Sign that check before Mr. Long shoots you, please. I tell you, it won't be any good. I'll worry about that. Endorse it. Don't say I didn't warn you. Don't, I don't even know what I spelled it right. Ah, that's fine. You don't deserve this, but I am an honest man, even among thieves. Here, here is your wallet back. And take my advice and burn those phony identification cards. Your 3,000 hasn't been taught. Oh, thanks, Mr. Arnold, but that check's no good.  You're no good. Such a strange sense of humor, Mr. Pemberton. Goodbye. Now that Chuck and I are leaving, Joan, I just wanted to tell you that I... I'm glad you're leaving, Francis. You are. I just heard Uncle Wills phoning Dr. Ben Meeder. Francis, if you don't get out of here, they're going to put you in a sanitarium. Oh, that's swell. Francis. No, I mean, it's swell. It's swell. That's why you want me to go. Hey, you're really worried about me, aren't you? Yes, I am. That's nice. Joan, do you like mink? Mm-hmm. What? You know, mink. Look, do you suppose you could sort of... Well, I mean, do you think you could take me at face value for, well, for the time being, that isn't... Joan, I know this all sounds confusing, but you understand, don't you? No, no, of course you don't, but never mind. Everything will be clear to you later. Francis, perhaps you should see a doctor. No, no, no. I'm fine, Joan. And... Take care of yourself, huh? Well, yes. I'll be... I'll be seeing you. Okay, Chuck. We're on our way. Just one moment. Francis, you're riding into town with me. I am. What for? To see Dr. Van Meter. Oh, no, no. I'm sorry. I'm going to Beaver Dam. No, no, you're not. Oh, yes, I am. Then I'll hold you here by force. I love... You will, huh? Oh, Francis! You struck me! Ah, you mind if I leave now, Uncle Willes? Oh! I'm proud of you. Congratulations. See you, Grandpa. Thanks. Goodbye, Grandpa. Goodbye, Joan. Bert! Bert! Yes, sir? Get that detective in here at once. Bye, Mr. Willes. Your nose is bleeding. I know my nose is bleeding. Get him in here.  And you keep your true sense out of this. I have a good mind to help you put out of the house. You can't. It says so on the will. You can't do a cock-eyed thing. Somebody sent for me. I'm on Francis Pemberton. Mr. Pemberton, but he left here 10 minutes ago. I know he left. Find him and bring him back. Use force if you have to. He's start raving mad. I'll answer the door, Bert. No, no, no. Don't worry about a thing. I'll have Mr. Pemberton back here. It's... Look. Look at the front door. It's him. Well, you haven't changed much in two years. Mr. Pemberton, but you just... Don't stand here. Get him. Say, what's going on around here? Hey! Take it easy, partner. Everything will be all right. Don't be all right. Just kind of go all limp, Mr. Pemberton. Or do I got to make you? Hey, will somebody please tell... Uncle Willes, what's the matter with this lunatic? I'm loony. It's a good one. Good work. Now, hold him there. I insist. Will somebody say something? Let go of me. Do you hear? Don't send for Dr. Henry.  This is a fine homecoming. Mr. Willes, may I say something, sir? No. But what shall I tell the driver? Driver? What driver? Here at the door, sir. He's insisting that Mr. Pemberton owes him $11 taxi fare. Hey, what kind of a gag is this? $11 for what? For hauling that guy he's sitting on out here from the airport. You mean you just brought him out from the airport? You half-baked fatfoot.  You're fired. You mean let him up? It's this fool detective, Francis. He mistook you for someone else, my boy. An imposter. I knew it. Imposter? Grandpa? Yeah, it could be. Well, Francis, my boy, welcome home from Mexico. Yes, sir. Check, we're practically on our way to Beaver Dam right now. There's a station down there in the next block. You know, Eddie, this is just where we was yesterday when that fella came up and stopped us. Yeah. You know what's kind of funny at that? Him walking up like that and saying, Hello, Mr. Pemberton. You know, it was almost like Oh, no. Any time you're ready, Mr. Pemberton. No, wait a minute. I'm not going to go through all that again. I think you will. Eddie, the same fella. The same gun. Yeah, it was that check that checked for 12,000 bucks it must have bound. Something like that, yeah. Mr. Arnold's very unhappy. Well, tell Mr. Arnold to move over. It's all mine. Let's go, you crooks. We pause now for station identification. This is CBS, the Columbia Broadcasting System. In just a moment, we'll return with a third act of Pardon My Past, starring Fred McMurray and Marguerite Chapman. We have as our guest tonight a young lady who though very young is known as one of the ablest actresses on the Columbia Lot. Let me introduce Miss Jeff Donnell of the Upturned Irish Nose, Hazel Eyes and Peacock Personality. Jeff, I understand you have a long list of fine parts to your credit. I'm still ambitious for more and better roles, Mr. Keeley, like the part that Rita Hayworth has in Gilda. She's wonderful in that picture. Glen Ford does a great job, too. Yes, and did you know that last week the Bobby Socks Club voted Glen Ford the man of the year? Well, I know Columbia searched a long time for just the right story for Glen and Rita. I was on the set while they were filming Gilda. I never tire of watching Miss Hayworth. And in this role, she proved herself a wonderful dramatic actress. She's so talented and so beautiful. We'll agree with you on all counts, Miss Donnell. Rita Hayworth is one of our favorite lux girls, you know. So she tells me, Mr. Kennedy, and don't think I'm not a lux girl, too. A nice complexion means so much before the camera. I'd say you have nothing to fear in any camera test, Miss Donnell. That gentle lux soap care seems to work for you as it does for so many famous Hollywood stars. Thank you, Mr. Kennedy. I do think lux toilet soap is as fine a beauty care as any girl could wish for. I really depended my lux soap facial. Thank you, Miss Donnell. Women everywhere have found that daily care with lux toilet soap really makes skin lovelier. Recent tests by skin specialists showed that actually three out of four complexions improved in a short time. And here's the beauty facial screen stars used regularly. Smooth the creamy lather well in. Rinse with warm water. Splash on cold. And pat with a soft towel to dry.  Smoother looks beautifully fresh. Try this gentle soap for your precious complexion. Use it as a luxurious bath soap, too. Why not put lux toilet soap on your shopping list tomorrow? Mr. William Keely returns to the microphone. Act three of Pardon My Past starring Fred McMurray as Eddie and Marguerite Chapman as Joan. Poor Eddie York. Trouble, trouble, nothing but trouble. You see, he looks like Francis Pemberton. Francis Pemberton owes Mr. Arnold $12,000. And no one will believe that Eddie isn't Pemberton. True, the real Francis Pemberton has just returned home from Mexico. But at this moment, Eddie and his friend Chuck are back in Arnold's apartment with their livid host shaking a large and worthless check under Eddie's nose. For two years, Mr. Pemberton. For two years, you cheat me out of my $12,000. And now you deliberately distort your signature on this check so the bank will not honor it. Well, how could I sign Francis Pemberton's name if I'm not Francis Pemberton?  Still on? Go downstairs and get the car. We're going someplace again? Definitely. We planned on going to Beaver Dam, Wisconsin. Your plans have been altered. I'm taking you back home. Oh, no. Francis, incredible as it seems, Joan and your imbecilic grandfather here allowed themselves to be taken in by an imposter. But who was he, Uncle Wells?  Well, your wall-eyed catfish, he was his twin brother. Ask Francis. Go on, ask him. I don't know, Uncle Wells. It's possible, I suppose. Mother and Dad told me I was adopted, of course, but they never mentioned a twin brother. I was there when they got you, identical twin baby boys, but somebody else had spoken for the other one. That is before they knew what allowed she was going to turn out to be, Francis. So I've got a brother, huh? Dead ringer, except he's got a backbone. Joan found him rather pleasing, didn't you, Joan? Yes, I did. Well, it's all ridiculously clear. He knows you're in Mexico. His wife and two of them, they schemed to kidnap Susan. Kidnap Susan? I don't believe it. Oh, don't worry, they won't get far. It isn't true, Francis. Mary only took Susan for the day. I know it isn't true. Uncle Wells, about Mary, are you sure the things that came out in court, the things you wrote me about, are true? Well, of course, my boy. I've had a lot of time to think things over. I came home because I decided that most of what happened between Mary and me was my fault. Francis. And I thought if I pulled myself together again, we could make a go of it again. But I can't understand Mary doing a thing like this. Kidnapping Susan. Son, a woman like that will stoop to anything. But don't worry, I've called the police. Now you're all tied out. Francis, you'd better rest. Yes, I... I think I'll go upstairs. Go ahead. I'll be back later. We'll have a nice long talk. Well, Joan... I just came in to tell you I'm leaving. You're leaving? I've made up my mind. Well, Joan, if it's because of what Uncle Wells said downstairs, I'm sure he was mistaken. Uncle Wells is mistaken about a great many things, Francis. If you'd just open up your eyes, it's not true what he says about Mary. He's only trying to... Oh, what's the use? We've been over this so many times. I'll come in and say goodbye before my cat gets here. Joan... You ring the doorbell.  Open the door. But I haven't got a key. I tell you, I don't live here. All of a sudden, a mink farm seems like a nice place to me. Mr. Pemberton, good evening, sir. Good evening, Bert. We're going into the library for a few minutes. Yes, sir. So there's no need to say anything to the family. We'll be going right out again. Yes, sir. Still, sir, you can't do this, Mr. Arnold. I am taking the equivalent of $12,000 from one of your first editions, Mr. Pemberton. If any further explanations are necessary, I will leave them to Mr. Long. Oh, Bert, was that my cat just now? It was him again, Miss. Him? The other Mr. Pemberton, the bogus one. Where? They went in the library. You sure it wasn't Francis? Positive, Miss. Why, I just brought Mr. Francis a tray. He's up in his room. Oh, I must notify Mr. Wins at once. We'll observe, Mr. Pemberton, that I brought along a catalog. You will get full catalog price for these books. Yeah, but it's still robbery. Yeah, I'll say it is. You pay $5,000 for Shakespeare and only $900 for Dickens. Somebody's getting rocked. Oh, hello, Joan. We came back.  The check wasn't enough. You had to come back with a second hand, man. Please, please, collect her. What you really mean is a receiver of stolen goods, don't you? Joan, I can explain all this honest, I can. It seems to me it explains itself. I was wrong, that's all. And don't let me disturb you. You'll find the jewelry upstairs and the silver in the dining room. No, Joan, wait. Ah, even your family seems to mistrust you. Well, don't stand there looking at the door, Mr. Pemberton. Here is a pencil and paper, make a list of these books and then sign them over to me. And please, this time, your correct signature, Mr.... Here, where are you going? Joan, Joan, where are you? Get him, Mr. Long. Wait a minute, Annie, I'll hold him here. Kate, give me that key. I want to play tag. No shooting, Mr. Long, no shooting in here. Get away from that window. No. Okay, you caught me. You took the key out of the window. If I was you, I wouldn't go out the window after it. Somebody might think something phony was going on and call a cops. Boss. Get the work on the door, quick. We've got to get Pemberton. Joan, where are you? Oh, hello, son. Grandpa, where is she? Where is Joan? In front of the house waiting for her taxi cab. Joan! Don't you come near me. Go after her, son. Don't let her get away from you. Wait, I want to talk to you. Oh, old man, where did he go?  Say, is that thing loaded? You'll find out if you don't answer, Mr. Arnold. Well, under the circumstances, seeing that he left here in such a hurry after you were locked up in the library, I guess he went for the police. Boss, cops. In my opinion, Mr. Long, this old man is lying. Mr. Pemberton is undoubtedly pursuing that girl. Why don't you just blow, Arnold?   Say, which Pemberton are you boys after, anyhow? Is there more than one? Oh, yes. That's impossible. I want Francis Pemberton. The worst well sure it has been my bad luck to ever come across. That could be him, all right. And I do not believe he went for the police. I could be mistaken. But he may choose to go to the police on a later and equally embarrassing occasion. I cannot take these books without him signing them over to me.  Do him a world of good.  You'll get? I'll be back here in a minute.  Ah, Mr. Long, this is an experience we will never forget. All these riches and not the same person in the house. Can you come in, Francis? Oh, hello, Grandpa. In the sleep, huh, Francis? Say, some man downstairs wants to see you. Oh, well, what was he? Seems to think you owe him a lot of money. I can't imagine who. Well, maybe he could kind of jug him every Francis boy. All right, I'll put on a robe and come down. Here he is, Mr. Here's Francis Pemberton. Mr. Arnold. Hey, Eddie. What's the idea to make up? I beg your pardon. Cut it out, Eddie. These mugs ain't kidding. Mr. Arnold, what are you doing here? What, Mike? For two fantastic days, I've been chasing you and you ask what I am doing here? Oh, you must have been involved with my twin brother. He's been around here impersonating me. Oh, your twin brother. He's not at York anymore, Mr. Long. No, now he's somebody's twin brother. Instead of beating you up, I should get ready for this moment as a public service. Oh, this is good. Mr. Arnold, exactly what do you want? What do I... All right, I will tell you once again. Two years ago, you placed a bet with me. That's right. I lost $12,000 to you at Hyalia. You act as though you hadn't been paid. I see if I hadn't... But I told my uncle to pay you. He evidently overlooked it. He certainly did. Well, I'll make you out of check right now. Oh, no, no, no, no, no. If you don't mind. Well, why you never refuse to check of mine before? Uh, would you mind writing your name, please? Well, not at all. There. Ah, Francis Pembert. Are you sure this time the signature is correct? Well, of course I'm sure. Uh, you. You seem to have an honest face. Is this his signature? Yeah, that's his, all right. Thank you. But when are you going to beat him up? All right, make out the check, Mr. Bemberton. Hey, Grandpa, is that him? Or him? Oh, that's him. Then where's Eddie? Eddie, hey! But, Joan, I tell you, I didn't know I had a twin brother. I had to pretend I was Francis. It was my only chance of getting our $3,000 back. You could have told the truth. Well, every time I did, nobody'd believe me. You wouldn't have believed me, would you? All right, I agree with you. I wouldn't have believed you. And furthermore, I don't believe you now. Oh, Joan, listen. Eddie, Eddie, is that you? Hey, the guy is back. Pemberton. Yeah, I know. Joan just told me.  He is? Joan, this is what I've been trying to tell you. Now I can prove it. I hope I haven't caused you too much inconvenience, Mr. Arnold. Inconvenience? No, no, no, not at all. Just here, here is your bomb check and your wallet with the $3,000. Bomb check? Wallet? Well, I can't take this, Mr. Arnold. It isn't mine. Where did you get this check? Why, you... No, no, no, no, no, no. Such a strange, strange case. Oh, this must be the check Uncle Wills was talking about. Oh, yes, yes, we... Mr. Long, come, I must get out of here. Coming out of the house? Mr. Arnold? Yeah. He's still got our $3,000. Hey, Mr. Arnold. Mr. Long, look, Pemberton. What we just left him is... Mr. Long, certain things are beginning to dawn upon me. Well, you've got your money, didn't you, from Mr. Pemberton in there? Just a minute, just a minute here, you are on the terrace and inside the house, sitting in that library where the light is... Is Francis Pemberton. So could I please have my wallet? Yes, I am beginning to understand then you are... Eddie York, that's what I've been trying to tell you. Sure, we're mink ranchers. Only we ain't got a mink or a ranch. Well, well, well... Mr. Long, we made such a mistake. Yeah, some joke. Mr. Arnold, my wallet. Oh, yes, yes. Mr. York, I have done your grave injustice. My profound apologies and your waltz. Here, now look, Joan, you see, there's our $3,000. Now do you believe me? Yes, I do believe you. Then let's go, Eddie, huh? We're off to the minks.  What do I want to talk to him for? But he thinks Mary kidnapped Susan. He does. Kidnapped?  Didn't anybody explain to him? Yes, someone did explain. Uncle Will's. Oh, I see. And Uncle Will's is called the police. Well, all right, I'll talk to him. But Joan, before I go in, there's something I want to tell you. Chuck, will you keep an eye on Joan's bags down the driveway there? Huh? Oh, I get it. Sure. Lamour. You know, Joan, when I talked to you this afternoon, when I thought Chuck and I were leaving... Yes. Well, I know I said a lot of things that didn't make sense, then, but at the time, I figured the sensible thing to do was for Chuck and me to go on to Beaver Dam, and then after we got all set, why, I was going to come back and ask you to marry me. You were, Eddie? Yeah, but, well, I didn't go, and now you're leaving the house, and that changes everything, doesn't it? Well, yes, I guess it does. But I think it's better this way, don't you? Because now we can all go to Beaver Dam together, and, well, while you're fixing up the house, Chuck and I can be out working with the minks, and how's that sound to you? Well, Eddie, I think it would be just the... Eddie, Eddie. I know you ain't interested, but do you hear that siren? The police? Yeah, coming up the driveway. Yeah, I'll take care of this. Eddie, but how? Look, that's Mary and Susan in the car. They found them. Yeah, I've been Francis Pemberton for two days now. I guess I can stand it for five minutes more. But if Francis should come out and found out... Don't worry. If he does, try to come out stalling. Well, I don't know Eddie. I don't know that... John, hurry up to here! Oh, uh, good evening, officers. You'll miss the Pemberton? That's right. Well, we got him.  I'm afraid there's been a little mistake, officers. Well, this here is her, ain't it? Well, yes. Francis, what a horrible thing to do. Well, I'm sorry, Mary. They're not going to take Mommy to jail, are they? Oh, no, of course not, Susan. I'm very sorry about all this, officers. I thought this was a kidnapping. Well, no, not exactly. Well, yes, it's to pick them up, didn't you? Well, yes, I did, but it was a mistake. Say, what kind of a razzle-dazzle are you people trying to pull? You think we're running a taxi service? The minute I heard it was Pemberton, I said to myself... Well, you did your duty, officers. Thank you very much. Thank you very much. You better watch your step, see? Wasting the taxpayer's money.  Francis, you must be out of your mind to humiliate me like this. You told me I could take, Susan.  I know, Mary. Then what happened? Well, Mary, I... Look, Joan's inside. Why doesn't Susan run in and... and Joan can put her to bed? She looks all tired out. Well, maybe you'd better, darling. Mommy will be in in a minute. Good night, Susan. Mary, Mary. All I can say is that I didn't do what you think I did. It was Uncle Will's. Uncle Will's? Yes. Well, you don't have to shout, Francis. Did Uncle Will's know when he telephoned the police that I had Susan with your permission? Well, you see, I... Or were you too weak-need to tell him? Oh, I was so hopeful this morning. It wasn't just that you let me take Susan. You seem so changed, so different. I see how mistaken I was.   Is that Grandpa there in the library window? Yes, that's Grandpa. I didn't realize we had an audience, Grandpa. Well, don't let me interrupt you, Mary. I don't know what an audience is a good thing sometimes. I think maybe you're right, Grandpa. If he had any brains in that skull of his, Francis Pemberton would do a little thinking. Well, I... I'll go in and say good night to Susan, and then I'll leave. I want to talk to you again, Mary. I wouldn't do you any good. Oh, don't say that.  If I have any sense at all, and I hope I have, why, it might do a lot of good. I'll be waiting for you in the library, Mary. All right, Francis. Hello, Grandpa. Where is he, Mary? Oh, there he is. Eddie Boy, you're wonderful. Are you sure Francis heard what we said? He's no account, but he ain't deep. I was sitting right next to him in the library. We heard every word. Now, when Mary comes down... I told her to meet me in the library. Don't worry, Francis will be there. He can pick up where you left off or not, but I still think it's best that Mary never finds out there was two of you. Uh, I guess maybe you're right. Eddie? Oh, uh, Joan. Uh, Grandpa, will you excuse us a minute? Oh, sure, sure.  Where's Chuck? Joan, uh, you never did get a chance to answer any of them about Beaver Dam, I mean. How about it? Well, Eddie, it sounds wonderful, but getting married is something a girl thought I'd have a little time to think about. Oh, sure, sure, I understand. I'll give you two minutes. Pardon me. Oh, Chuck. In case anybody cares, there's another car coming up. Uncle Will's? He gets a chance to talk to Francis before... Look, uh, do you think Francis would listen if Uncle Will's told him himself? Of course he would. That's all I wanted to know. Chuck, start walking down the drive. I want Uncle Will's to see you. Hmm? Oh, okay, mastermind. And Joan, uh, you'd better get out of sight. And, uh, keep thinking about that, will you? I ain't had so much fun in years. I'll just, uh, stand here in the terrace and hope for the best. Hi, Uncle Will's, old kid. How's the old schnoz? Oh, so it's you, is it? Yeah, you want to make something out of it? Well, I'll attend to you later. Is that you, Grandpa? It ain't Sandy Claus. Well, did they get him? That imposter? Yep, they got him. He's in the library, Will's. We're just waiting for the police to take him away. Uh, Uncle Will's, I haven't time for you now, Francis. I've got a few things to say to that criminal in there. But I want to know what's going on. He's made some pretty serious charges. Charges? What charges? Against you. Oh, that's ridiculous. And while I was away, Mary wrote me some letters. What happened to it? Well, I destroyed them. Anything I've done has been done entirely in your own interest.  You just wait a minute. I found out that Mary didn't kidnap Susan. She thought she had my permission. And you knew that when you called the police. I'll explain everything later.  I have a few things to say to that imposter. Well, my fine-freithed friend, it didn't work out, did it? No, I guess it didn't. Coming here posing as Francis Pemberton. What kind of a child do you think I am? But I understand you made some charges against me. There will be a few more, too. That's absolutely nothing you could do that could embarrass me in any way.  Oh, I have. So I'll make you a proposition. Promise to get out of town, and I'll make good that check I gave you this morning. If you don't, I guarantee to put you behind the bars for 20 years. Do I make myself clear? Very clear. Good.   What are you talking about? About a little mistake you've made. I'm Francis. Francis? I just sent Francis up to his room. I know. I heard you talking to him. Except it wasn't Francis. It was my twin brother. Uncle Wills, I don't know exactly what you're trying to pull, lying to me about Mary and sending me off to Mexico. But whatever it is, it's all over. Now, wait a minute, Francis. I can explain. You can save your explanation for the auditors because I intend to find out for whose benefit you've been managing my affairs. Now, get out of here. What, my dear boy? Francis, I said get out of here. Stay out. Francis, you've done it. And right down the schnoz again. Francis, you... Mary, don't say anything, Mary. Just try to forgive me. And stay here. Please stay here. Oh, darling. Darling. Francis has come to his senses at last, thanks to you. Yeah. You know, Grandpa, I kind of wish I'd met him at that. He'd be worth meeting now. Yeah, but I don't think now's quite the time, Grandpa. Eddie, can we please get out of here? What about them menks? Well, that's right. Well, come on, Joan. But, Eddie, I haven't said I'd go yet. Well, that's right. You haven't, have you? Well, will you? Of course, you will. Won't you? Well, I... Well, yes. There you are. Goodbye, Eddie. Goodbye, Grandpa. Goodbye, Joan, dear. Goodbye, Chuck. So long, Gramps. Hey, wait a minute. That's my car. That's right, Uncle. And you're driving us into town, ain't you? I most certainly am not. Ain't you? Oh, very well. Get in. Everything's all set, Joan. We can get on the train in five minutes. Just a minute. Oh, no! Oh, relax, Mr. York. Relax. I forgot for a minute. Here. Here, this box with my compliments. For me, Mr. Arnold? Open it. Now, look out, Eddie. It's probably a bomb. I regret so much the inconvenience I have caused.  Eddie! Oh! Hey, this is wonderful, Mr. Arnold. Chuck! Look! Eddie, rats! Eddie! They're minks! Sure they're minks! They agree. They're here on the paper. Yes, I don't know what to say, Mr. Arnold. Joan, this puts us right in business. They're beautiful. Mr. Arnold, thanks. If you ever get the beaver dam, you look us up, huh? Well, thank you. Well, goodbye, Mr. York. Goodbye, miss. Goodbye, clock. Chuck. Oh, I love to see happy people.  Well, you can start right now. All right. Here, hold this box, Chuck, will you? I hope I don't have to listen to this mush all the way to Wisconsin. Chuck can ride in the club car, can he, Eddie? Sure, Chuck and the minks. If anybody ever told me I'd wind up as nice-mate to a couple at... Hey, Eddie. Hey, Eddie! What's the matter? The box. Something's happened to them or I got the DTs. Why, they... Yes, they have. One, two, three, four, five. Five kittens. Eddie! Hey, what do you know? 250% profit already! We take leave of Joan and Eddie on their way to Beaver Dam and meet them again as they are in real life. Fred McMurray and Marguerite Chapman. Fred, I don't think many of our audience know that Beaver Dam is actually your hometown. Well, that's right, Bill. It's a great place, too. I grew up there. Is that where you learned to play the saxophone? Well, Bill, let's just say that that's where I tried to learn to play the saxophone. You must have had some very tolerant neighbors, Fred. Well, I didn't have them very long, if you get what I mean. What's your hometown, Bill? Philadelphia. But my ancestors came from the English town of Keely. K-E-E-L-E-Y? No, spelled like my own name. K-E-I-G-H-L-E-Y. I understand, Marguerite, you came from White Plains, New York. That's right, Bill. As a child, my ambitions were to become an actor. I hope in your early training you didn't overlook lux toilet soap. As a matter of fact, I've always used lux toilet soap for my complexion. It's a great help.  Well, that's one we'll have to see. What's the title, Marguerite? The Walls Came Tumbling Down. Well, I'll pick a seat where I won't get hit. Put a tack on the seat, Fred, and you'll have the name of your next Paramount production. Suddenly, it's spring. Sudden spring, you get the point, Fred? Well, no, but while I'm working on it, why don't you tell us what you have for next week, Bill? Next Monday night, we're bringing our audience RKO's exciting mystery, Deadline at Dawn. Starring Joan Blondell, Paul Lucas, and Bill Williams. Take a baffling murder mystery, set a deadline on resolving it, and you can get ready for plenty of breathtaking thrills, fast action, and suspense with more than a sprinkling of romance. I wouldn't miss it, Bill. Good night. This is CBS, the Columbia Broadcasting System.