From this station today (G4IYK), signals on both 80m and 60m were down below the noise although on 80 meters signals were reasonably audible using the Kenwood TS570D with the attenuator switched in.
Very different on 60 Meters using the PRC320 – where very little was heard.
For both sessions I ended up using the Hack Green Web SDR to receive and the audio is published below. As you will hear – mostly good copy except for some fading on 60m.
Have spent some time now (Sunday) setting up the computer to use the Windows 7 Audio mixer to compare results with. The link (see here) is to a screenshot. On the left is the Hack Green Rx showing the waterfall display and on the right my own local receiver (using Power SDR) with its waterfall display. The mixer is overlaid.
Using the mixer I can now compare the audio from both Receivers through the same headset. (I had to fix the Bluetooth issue first.)
The difference is quite overwhelming – on 80m, tuning the same station resulted in nothing but QRM on my own Rx but S9+20 signals at Hack Green. See also correspondence below. I did get a better result on the 60 and 40m bands.
Now I can see what is going on using the waterfall display. This shows up broadband noise characteristics – as you can see in the screenshot on the right it is showing interference across the 40m band, displaying vertical stripes at intervals across the spectrum. A bit like turning up at a swimming pool to find an oil slick.
On Net Today
Mike, G3RE (G4ICC). Gordon, G3WOV. Jack G3PWK. Tom, G4CMG, Bill, G4NRE and Derek, G3XWD.
80m between 0745 and 0800 and 60m between 0800 and 0830 from the hack green site.
The following message was sent to the sysops at Hack Green.
“Just a note to let you know we are enjoying your set up at the secret nuclear bunker. It has not escaped us how quiet the receiver is compared to the urban noise levels being experienced by most of us. For the last several weeks we have learnt some interesting things from it. Thanks – I hope you keep it going.”
Reply received from Joe Bell, G4PMY:
“Many thanks for your kind comments. We have worked hard on the system, particularly software embedded in the SDR receivers which were of our own design, and aerial distribution system with filters. An aerial upgrade is planned in the near future.
The plague of urban noise is simply not going to go away, and the flood of cheap Chinese equipment adds greatly to the problem. We not only stream amateur HF/VHF onto the web but also by request “other” traffic for MoD and MARS radio service
I am going to live in New Zealand next year, so I do hope the SOT radio club keep the system going as it would be good to tune into the UK from time to time.
Cheers & 73s
Joe Bell G4PMY”