Tagged: New Uno user
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December 12, 2020 at 9:13 pm #1538IanFParticipant
I’m new on the group. I’m ex Civ Service RO with a lot of experience in Comms generally, but if ever I had a problem then I yelled for a Tech. That now has to change! I’m currently reading up on he RSGB Novice exam requirements and hope to sort that in the new year.
I’ve put up a Sloping V centred on the 40M band, coax fed with good quality cable.
I installed the RSP1A and the Uno software and have been experiencing problems, which I’m beginning to suspect are down to my own ineptitude with the software.
This afternoon I had a noise floor around -120 to -130 and lots of morse activity on 7MHz. I left the kit running while I was out for a couple of hours and when I came back things went a bit wrong.
Still being in ‘poke it and see what it does’ mode, I changed the Decimation from 1 to 2. The noise floor shot up to around -60 with only a few big signals showing. So, I immediately changed the Decimation back to 1. No change in the noise floor or visible/audible signals, still -60 noise and virtually empty spectrum. I tuned around between 3MHz and 10MHz but all bands show the same high noise.
I’ve restarted Uno twice, done a Reset to Default – no change.
Can anyone offer any advice on what I’ve broken, please?
IanFDecember 15, 2020 at 8:52 am #1543Andy2Participant
What happens if you remove the antenna? Is it possible you have a local noise problem that has just appeared (Christmas lights etc)? If this persists, I’d recommend a visit to the ‘support’ tab on the main site. The team is very helpful.December 15, 2020 at 9:16 am #1544IanFParticipant
Thanks for the reply. I’ve just done what I should have thought of before – removed the antenna from the Rx. Noise drops drastically!
I’m just waiting for delivery of a ferrite Toroid which I was going to put in the supply to the PC hoping that might help, but if the noise is coming through the antenna then that probably won’t help.
I live on an ordinary housing estate with no industrial units nearby which could be generating the RFI,so unsure what to do next.
IanDecember 15, 2020 at 1:42 pm #1545Andy2Participant
Ian – A few random things to check, if you haven’t already: Reduce RF gain or select the MW notch, just in case something is overloading the front end. Overloading often causes the noise floor to shoot up. Check the braid of the coax is connected. If it has come off at the receiver end, you will get noise from your own computer etc. Check you haven’t switched on something nasty! We have two LED room lights, one in the kitchen, one in the bathroom and although they don’t have a dramatic effect across the bands, they do radiate narrow-ish bands of ‘FM hum’ at harmonics of the switching frequency.
I can’t think of anything else right now. Good luck with it, it’s a growing source of frustration.December 15, 2020 at 2:21 pm #1546IanFParticipant
Thanks, Andy, I’ll check those ideas later thisaft.
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