Hello everyone,We’ve seen some people receive broadcasts without optimising their SDR receiver to reduce fading, get higher fidelity audio and reduce noise so we have written this short guide to give you a few ideas to optimise listening to us (and other broadcasters)! 😄
First, we’ll show you a little demonstration of how AM is demodulated on SDRs
Note: We have decided not to use all the technical terminology to summarise things in a very easy way to understand. This guide is a rough idea, if you want to learn more you should probably do some research on Google! 📖
We are using SDR# for these examples.
What can be done to help?
In most SDR software there is an option called AMSync or DSB (SAM in KiwiSDR), these options are magical for reducing fading distortion. These modes generate their own carrier meaning that when the carrier fades for a moment, the audio doesn’t distort!
In the same example this would happen:
This is a short video demonstrating AM mode and then DSB mode on ÖRF’s broadcast:
2 More useful tips
There are 2 other things to do to get the best sound from a broadcast; Filter bandwidth and Noise reduction!
We’ll start with noise reduction. On SDR# there is a simple check box and slider. What you want to do it set it to -30dB, if you hear noise: good, if not: lower it until you hear noise.
Now you want to dance it around a few dB at a time until most of the noise is gone but little of what you want to hear is!
And lastly, check your filter bandwidth!
Most stations broadcast at at least 5KHz audio (10KHz filter BW) so make sure to widen those filters. If you leave them narrow you’ll loose out on the higher fidelity sound!📻🎶
Hopefully these tips have given you ideas on how to optimise how you listen to RNEI and other stations on SW,
Wishing you all the best! 😄