How do I test for blown finals?

General discussion and support for the Peaberry SDR V2.

How do I test for blown finals?

Postby K0ZYV » Sun Jan 18, 2015 1:57 pm

How do I test for blown finals? On receive I measure about 200 ma current draw, and on
transmit to a dummy load on 80 meters about 590 ma. I cannot see any output on my milli watt meter.

How do I check the finals?

thanks, Paul K0ZYV
K0ZYV
 
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Re: How do I test for blown finals?

Postby AE9RB » Sun Jan 18, 2015 4:45 pm

Did you perform the oscilloscope tests in the manual? Is this a new build? Did it ever work? Are you sure your watt meter can measure 1 watt? Could it be a software/pc issue? Why do you think the finals are blown? ESD? Overcurrent? SWR?

Here's how to test a MOSFET with a multimeter:
https://www.google.com/search?q=how+to+test+a+mosfet
73 David AE9RB
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Re: How do I test for blown finals?

Postby K0ZYV » Sun Jan 18, 2015 6:31 pm

I did not have access to an oscilloscope, but will have shortly. It did seem to work and I
am using a milli watt meter from Kees. I am fairly sure it is working properly. It did work
on 80 and 40 (according to the meter) then I tried it on 30 by mistake. With no output, I stopped it immediately. It shows no output on 80 or 40 now. It is possible I changed the
software setup unitentionally.
thanks,
Paul K0ZYV
K0ZYV
 
Posts: 12
Joined: Sun Jan 06, 2013 9:16 pm

Re: How do I test for blown finals?

Postby AE9RB » Sun Jan 18, 2015 7:48 pm

An oscope makes these problems so easy to find. Just follow the TX path on the block diagram until the signal vanishes.
73 David AE9RB
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Re: How do I test for blown finals?

Postby K0ZYV » Tue Jan 20, 2015 2:23 am

I have an oscilloscope now, and will follow your suggestion. Sometimes it
will output about .6 watt, so my guess is that the finals are okay. Bug someplace!

thanks,
Paul K0ZYV
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Posts: 12
Joined: Sun Jan 06, 2013 9:16 pm


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