Many years ago i build an SDR Display for GB3KM.
This allowed us to tap into the various IF’s available for different bands at KM and display a spectrum of narrowband signals on a waterfall display.
The new version will be HDMI output rather than Composite video but still based around a raspberry pi (4 this time). I will be using 4x IF Splitters that i designed a few years ago. this will replace the 6-way mechanical switch i was using before.
The IF Splitters also provide bias T’s too so will become a main part of the repeater Rx system.
Here’s a block diagram of how it’s looking:
I’ve been working on a web page based SDR display for my Deep Space receiver and I have used parts of the code for this project too. It uses python-flask server with socketio to get the spectrum data to the webpage, all hosted on the pi. I just call a number of piped programs in C that I’ve created, these tune, decimate, filter and FFT the IQ data. This is then piped into the python code and out to the webpage.
It’s very buggy still but will make it quite versatile to do what we want it to do…
Requirements are to be able to monitor narrowband beacons at various span/bin widths and also to be able to monitor DATV signals up to 1MHz bandwidth. I’d like to record signal strengths over time to at some point.
Some photos of initial testing stage:
An update will appear once it’s complete, but it’s all software from now on!
