Search found 178 matches

by JEL
Fri Aug 28, 2020 2:45 pm
Forum: Signal Identification Help
Topic: Is this interference i see at 137MHz?
Replies: 23
Views: 6248

Re: Is this interference i see at 137MHz?

This one i call the airband monster. I get those too. I am using the Airspy HF+ Discovery, but with that radio they are dependent on the gain (Or attenuation, as it is on the discovery) If I change the attenuation they will either show up or go away, at the frequency I am on. So that obviously make...
by JEL
Mon Jul 20, 2020 6:41 am
Forum: Antennas
Topic: Airspy YouLoop
Replies: 17
Views: 5686

Re: Airspy YouLoop

I'd say you've done pretty well, working with the restrictions put on you by the HOA. Are you using a balun or transformer to match the feed lines to the loops? Why did you not feed them both the same way? You mentioned your noise floor is some concern. Mine varies quite a lot, and as I sit here ty...
by JEL
Sun Jul 19, 2020 4:25 am
Forum: Signal Identification Help
Topic: switch mode power supply? (Tone sweeps)
Replies: 0
Views: 1072

switch mode power supply? (Tone sweeps)

It seems whenever people post spectrum-grabs like the one I have attached below, the source is called out to be a switched-mode-power-supply (Often known as 'SMPS' on google apparently) Does the spectrum I attached look like such a thing? There are multiple sweeps. They do not all sweep the same way...
by JEL
Sun Jul 19, 2020 4:07 am
Forum: Antennas
Topic: Airspy YouLoop
Replies: 17
Views: 5686

Re: Airspy YouLoop

The loop I made myself is at lawn-level, so despite being big it is not 'up there' where it would probably be receiving much better. From what I've read and seen on numerous YouTube videos, the height above ground isn't all that important. If you can get it up about two loop diameters above ground,...
by JEL
Wed Jul 01, 2020 2:26 am
Forum: Antennas
Topic: Airspy YouLoop
Replies: 17
Views: 5686

Re: Airspy YouLoop

Do you have a diagram, or maybe some detailed photos, for the new loop you made? I do have a tall tree nearby, that I wish I could 'decorate' with some wire, but the rules around here does not allow for putting up an outside-antenna, so looking for any possible alternative that can yield extra SNR :...
by JEL
Thu Jun 25, 2020 1:52 pm
Forum: Signal Identification Help
Topic: Is this interference i see at 137MHz?
Replies: 23
Views: 6248

Re: Is this interference i see at 137MHz?

The minimum noise-floor you can expect with the RTLSDR is probably not much lower than around 50 or 60 dB, so it does indeed sound like an LNA is necessary for your needs. I saw a video on youtube where somebody tests the BCFM and BCAM filter and concluded they lower the signal by about 50 dB, so se...
by JEL
Tue Jun 23, 2020 1:05 pm
Forum: Signal Identification Help
Topic: Is this interference i see at 137MHz?
Replies: 23
Views: 6248

Re: Is this interference i see at 137MHz?

You mentioned you're getting a band-pass filter. Which frequency-range is that letting through? This will probably be your best bet at removing those unwanted spikes. You also mentioned the broadcast-FM (BCFM) stop-filter, which I find is brilliant (If it's RTL-SDR's version you're getting, which is...
by JEL
Tue Jun 23, 2020 12:06 pm
Forum: Antennas
Topic: Airspy YouLoop
Replies: 17
Views: 5686

Re: Airspy YouLoop

Hahaha nice, tinkering is a lot of fun :)

I do hope you have fun using it too though, but I couldn't help but laugh when I read your comment :)

My own skills in antenna-design are very limited, so I'm not sure if a DC short-circuit is necessarily a bad thing.
by JEL
Sun Jun 21, 2020 12:11 pm
Forum: Signal Identification Help
Topic: Is this interference i see at 137MHz?
Replies: 23
Views: 6248

Re: Is this interference i see at 137MHz?

I was just about to say "Welcome to the hobby" :lol: Maybe somebody else with more knowledge and experience than myself can chip in, because I'm not really sure what you are up against. I want to show you one thing though, which I battled for a while some years ago: A neighbors guitar-amp :shock: ht...
by JEL
Sat Jun 20, 2020 9:53 am
Forum: Antennas
Topic: Airspy YouLoop
Replies: 17
Views: 5686

Re: Airspy YouLoop

When I follow the red wire from the connector-plug side (The red center-pin wire) I can only count 1 loop in the most direct electrical connection. (Through the green connection you get a single electrical loop and through the black connection you get two electrical loops) So what is the benefit of ...