As expected, other than an EA8 station apparently responding to a small, high latitude field disturbance before midnight, there were no overnight spots of any station at all, until well into the advancing ionospheric morning.
Earlier, I also ran a comparison of an elevated quarter wave vertical against my vertical delta loop, the former antenna running in the middle of a field, very far from any domestic mains electricity noise.
Unfortunately, I've discovered that there is (for critical WSPR use) fairly significant RFI from the Raspberry Pi computer, propagated by the various connections, especially that from the cable from the USB port to the sound card. This should be a fairly easy noise elimination process. But do beware the Pi, because it can have a significant impact on background noise levels, despite being quite small.
Despite this, my vertical quarter wave was producing spots on average only 2.5dB weaker than the delta loop, which catches a lot more wind and is somewhat more complex to deploy than the former antenna. When I address the RFI, I expect this difference will vanish, or even reverse.
1 comment:
Hello John, best wishes to you and yours for 2019. The USB RFI is indeed something many do overlook. If the RFI cannot be solved by ferrite you could look at the ZLP electronics USB isolator. I'm still monitoring 20m 24/7 for the last week. However I'm not in the WSPRchallenge list anymore since I spot below 100 different stations. I found the number has dropped the last few days. Have been looking and listening to the radio but do not hear anything different, no extra noise, antenna still the same SWR and position. Nothing changed so it has to be propagation. My 1W signal was still spotted in VK, ZS and many other DX, nothing wrong with the antenna. 73, Bas
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