Half of my spectrum is constanly +30 dbz in the red!

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bubblegumpi
Posts: 49
Joined: Fri Oct 14, 2016 11:41 pm

Half of my spectrum is constanly +30 dbz in the red!

Postby bubblegumpi » Tue Dec 13, 2016 10:48 am

amwtrap15mhz.jpg
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bubblegumpi
Posts: 49
Joined: Fri Oct 14, 2016 11:41 pm

Re: Half of my spectrum is constanly +30 dbz in the red!

Postby bubblegumpi » Tue Dec 13, 2016 10:52 am

OOPs here the rest of my post:

This has a longwire>homebuilt AM trap to balun.But even without the trap (its new) the left halfof the waterfall is always filed with noise?

I'll post more on the trap but this doesn't seem to be related. When you scroll up or down the spectrum always looks the same with signal popping out on the right but then they get lost in the noise as you scroll up in frequency. I have had little phantom peaks stick around on the left side of the spectrum that don't "move" left as you tune up but this is half the spectrum. I even set my spectrum to 1MHz because I know this computer has its memory tied up,
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13dka
Posts: 127
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Re: Half of my spectrum is constanly +30 dbz in the red!

Postby 13dka » Tue Dec 13, 2016 12:31 pm

Your LO offset is around 500kHz in all 3 screenshots, but you say you selected a bandwidth of 1MHz, so you're tuned to the right edge of the spectrum all the time. Get LO and tuner frequency closer together.

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PG3
Posts: 29
Joined: Mon Nov 14, 2016 6:04 am

Re: Half of my spectrum is constanly +30 dbz in the red!

Postby PG3 » Tue Dec 13, 2016 8:44 pm

Try UN-zooming all the way out. It looks like you might be zoomed in on the end of your IF passband.
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Devotech
Posts: 8
Joined: Mon Sep 19, 2016 5:32 pm

Re: Half of my spectrum is constanly +30 dbz in the red!

Postby Devotech » Wed Dec 14, 2016 6:47 pm

I have had this happen also (SDRuno 1.11 & RSP2). I had tried restarting SDRuno, changing bands, tuning to random areas, etc. The only thing that worked was changing the selected bandwidth on the Main panel. Once I did that everything returned to normal and I was able to return back to my original bandwidth and all was again receiving as normal.

Tom

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bubblegumpi
Posts: 49
Joined: Fri Oct 14, 2016 11:41 pm

Re: Half of my spectrum is constanly +30 dbz in the red!

Postby bubblegumpi » Thu Dec 15, 2016 8:25 pm

13dka wrote:Your LO offset is around 500kHz in all 3 screenshots, but you say you selected a bandwidth of 1MHz, so you're tuned to the right edge of the spectrum all the time. Get LO and tuner frequency closer together.

So how do I change the LO offset? What does that do? Is it something you can play around with?

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bubblegumpi
Posts: 49
Joined: Fri Oct 14, 2016 11:41 pm

Re: Half of my spectrum is constanly +30 dbz in the red!

Postby bubblegumpi » Fri Dec 16, 2016 12:46 am

Devotech wrote:I have had this happen also (SDRuno 1.11 & RSP2). I had tried restarting SDRuno, changing bands, tuning to random areas, etc. The only thing that worked was changing the selected bandwidth on the Main panel. Once I did that everything returned to normal and I was able to return back to my original bandwidth and all was again receiving as normal.

Tom

This did work, I set it from 1 to 2 . But that changed the LO. So how do I actually set the LO? The SDRCook book doesn't really tell you what this stuff does or why its important. Also its heavy on the acronyms which can really slow down a beginner. I do know a little bit about electronics and RF so its a matter of matching up my knowledge. Once I know the why I can usually figure out stuff on my own.

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13dka
Posts: 127
Joined: Sun Feb 14, 2016 8:40 am

Re: Half of my spectrum is constanly +30 dbz in the red!

Postby 13dka » Tue Dec 20, 2016 10:50 pm

bubblegumpi wrote:
13dka wrote:Your LO offset is around 500kHz in all 3 screenshots, but you say you selected a bandwidth of 1MHz, so you're tuned to the right edge of the spectrum all the time. Get LO and tuner frequency closer together.

So how do I change the LO offset? What does that do? Is it something you can play around with?


Just click into the spectrum until the numbers (receiving frequency and LO frequency) shown to the right of the spectrum roughly match.

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