Jonti's Web Site

A place where I put things on the Web


Experimening with digital SCA signals. SCA is a way to add another audio channel to an FM transmitter. DSCA (Digital SCA) is a digital version. Here I see how it goes


A program to demodulate and decode Classic Aero satellite communication ACARS. This program can be used with an RTL-SDR dongle and a homemade L band antenna to receive ACARS (Aircraft Communications Addressing and Reporting System) communication from satellites to Aeroplanes. Such information contains weather reports, flight plans etc.

GPS Basics

The Global Positioning System (GPS) is pretty cool. See how the signals can be used to figure out where you are in the world. Here we delve into the murky inner workings of GPS from the end users point of view. What are the signals that arrive at your Cell phone’s GPS receiver, and what does it do to turn these into an answer that tells you where you are. Find out that answers to these questions here.


A program to demodulate MSK signals. Its a coherent demodulator with performance similar to BPSK. It can be used with cheap $5 DDS modules as found on Ebay to create a long range transmitter while still producing side lobes low enough to be acceptable for transmission.

How this web site works

See how this Website is put together and how general HTML pages are incorporated.
I have updated the theme of my website after a long period of time of being unable to make any changes to it due to Microsoft pulling the rug from beneath my feet after they got rid of FrontPage.


The fascinating structure of a high speed modulation technique.

QAM idea

Eye diagram


An FM stereo encoder for FM stereo broadcasts. Implemented in software for a computer soundcard.

IIR pre-emphasis investigation and implementation

Interesting investigation into theory of IIR filters and how to design and implement a digital pre-emphasis filter.


I can’t really play an instrument very well, but that doesn’t stop me making some music. After one week from picking up a guitar, in an angry mood I put the following song together, it’s just guitar and me voice, but people find it amusing so here it is. WalkOn.mp3.

Then after a few more weeks I put together this one. It’s more polished. I was going for a “only shallow” by “my bloody valentine” sound. Long.mp3.

And here are some more, TCM all about well TCM. Dumb arse (kind of short). Won’t Win, Ahha, Ode 2 Edger.

One by the STDs, Dutch Tourist.


How about computer plots and animations as art? art.

Cyclone Pam

Cyclone Pam taken using an SDR-RTL dongle as it approaches New Zealand

Jonti. Last modified Sat, 25 Mar 2017 00:22:32 GMT.