Neutral Hydrogen Detection - sigh.....

[saac]

23 hours ago, Ed astro said:

 

Ed that is a really cool setup, would be good for outreach. 

Jim 

[Peter Masters]

Yes, I'm none the wiser about those bumps in the output.  I tried to get a reading on Saturday and it took me 4 hrs in the morning to capture the background, then I managed to get 1 reading in the afternoon, which was completely flat.  This is most likely because it took so long.  I'm not currently hooking SDRSharp up outside to the received, but using spyserver in the middle with a PI (as PI's are more portable to the garden and easier to waterproof!).  In other words, I have a desktop PC running SDRSharp doing a TCP/IP connection over WIFI to a PI running spyserver, which has the SDR and antenna etc connected.  The WIFI is good and I don't think it is responsible for the 4hr delay, but my next test will be to hook the sdr directly up to my PC and see if that works better.  It might account for the 4 hr delay, the bumps or whatever.  There isn't much in terms of guides on IF Average plugin - does changing the level/gain invalidate a (background) capture if its in progress?

Anyway, at the moment, based on the last couple of replies, I was having better success with the original VIRGO software, as I at least had a graph matching Ed's with the 3 peaks (tho no hydrogen bump).  At this rate, I'm expecting someone to show me they can pick it up with a milk bottle top, but that was a good graph, thank you!  I think you're right and that this is software - I can pick up other things like FM radio, the antenna etc fundamentally works and I have to assume it is getting at least reasonable gain on it (more than just the waveguide horn shown above anyway).  

[Carl Reade]

9 hours ago, Peter Masters said:

Yes, I'm none the wiser about those bumps in the output.  I tried to get a reading on Saturday and it took me 4 hrs in the morning to capture the background, then I managed to get 1 reading in the afternoon, which was completely flat.  This is most likely because it took so long.  I'm not currently hooking SDRSharp up outside to the received, but using spyserver in the middle with a PI (as PI's are more portable to the garden and easier to waterproof!).  In other words, I have a desktop PC running SDRSharp doing a TCP/IP connection over WIFI to a PI running spyserver, which has the SDR and antenna etc connected.  The WIFI is good and I don't think it is responsible for the 4hr delay, but my next test will be to hook the sdr directly up to my PC and see if that works better.  It might account for the 4 hr delay, the bumps or whatever.  There isn't much in terms of guides on IF Average plugin - does changing the level/gain invalidate a (background) capture if its in progress?

Anyway, at the moment, based on the last couple of replies, I was having better success with the original VIRGO software, as I at least had a graph matching Ed's with the 3 peaks (tho no hydrogen bump).  At this rate, I'm expecting someone to show me they can pick it up with a milk bottle top, but that was a good graph, thank you!  I think you're right and that this is software - I can pick up other things like FM radio, the antenna etc fundamentally works and I have to assume it is getting at least reasonable gain on it (more than just the waveguide horn shown above anyway).  

Hi maybe a factor maybe not I had read that the PI itself like most computers can cause interference via RF and needs to be a good distance from the LNA and antenna. Maybe the bump issue especially if it's using WiFi as well.

[Peter Masters]

Yeah it does actually cause a lot of interference, so I had moved it 5m away (using USB extension cables between it and the SDR) and I also wrapped it in tin foil (clingfilm first to ensure the tin foil didn't cause connections on the PI).  I don't think that is the issue still because I'd be seeing spikes on particular frequencies.

[Alex_Fla]

This is a very Old post, but I will suggest a few videos .. if you have any questions, Please Ask !  ..  Alex P

 

 

 

Edited September 13, 2023 by Alex_Fla

[Alex_Fla]

Finally got around to processing some 24 hour drift scans from March ... This is my 1.2 meter diameter Radio Telescope tuned to the 1420 MHz Neutral Hydrogen RF Emission frequency of the large hydrogen clouds within the Milky Way.. The Y Scale is their Velocity relative to Earth ... up to ~90 Km/Sec .. This is a slice at Declination + 40 degrees. Alex

[athornett]

Hi Peter,

I hope you've had some success now. I've had some success - see www.astronomy.me.uk for my setup and software I use. Keep going. You will detect hydrogen at.some point!

Andy