PSoC noise

General discussion and support for the Peaberry SDR V2.

PSoC noise

Postby hsquared » Fri Feb 20, 2015 5:08 pm

When I power-up PB and HDSDR I seem to get clean reception for about 30 seconds then the audio and the waterfall are overwhelmed by
noise, if I blow canned air on the PSoC it clears up briefly then back to noise. Reflowed all legs on chip and no help, I did snag and bend
# 5 pin with solder wick but repaired. My question is should I replace the PSoC or look elsewhere? I welcome any suggestions.

Charles KG7LQH
hsquared
 
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Re: PSoC noise

Postby TerryFrench » Fri Feb 20, 2015 5:24 pm

I'm really not an expert, but I built a Peaberry (and other kits).
You seem to have one (or more) bad soldering joint somewhere. Something gets hot, expands a little and maybe doesn't make a proper contact (or makes an intermittent one).
These can be tricky to check, but I would advise using a good loupe (good quality 10x or more magnifier), and looking at the psoc pins (but not only these) once the issue does repro. That might or might not be visible. The difficulty is that if you use a multimeter probe, you will push down the joint and it will work when you measure it. BUT you could try the "toothpick" method: get teh system warm/reproducing the issue, then with a thin toothpick, go push the pins one by one. You might find the one that is causing the problem.
You might also want to consider reflowing every pin again.

Also the cold air on the psoc is not only on the psoc but also around it. So the bad solder joint could be in some other parts of the board.
Note that someone else here might tell you what pins could more likely create the issue to narrow down your search.

Good luck, you are almost done (at least for the receive stage).
TerryFrench
 
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Re: PSoC noise

Postby hsquared » Sun Feb 22, 2015 9:10 pm

After almost 2 weeks of trying to trouble shoot my PB receiver problems guess what? I tried a different usb cable and now it works, "doh". :oops:
Thanks for the advice.

Charles KG7LQH
hsquared
 
Posts: 5
Joined: Wed Jan 28, 2015 9:29 pm

Re: PSoC noise

Postby TerryFrench » Mon Feb 23, 2015 6:17 am

Glad you have it working with the different cable (even if my comments were not helpful ;-) )
TerryFrench
 
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Re: PSoC noise

Postby hsquared » Mon Feb 23, 2015 5:21 pm

By the way Terry, before I found my defective usb cable I did follow your advice and examined my solder joints with a usb microscope
and found several questionable connections leading to hopefully a better build. And again thanks you taught me it pays to be thorough.
hsquared
 
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Joined: Wed Jan 28, 2015 9:29 pm


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