[hpsdr] P SDR 2 Tone Generator

[Kjell Karlsen]

Hi Frank.

I have done a lot of 2-tone tests using Penny and PSDR and find that the  
spectrum from Penny is extremely clean up to the point where the amplifier  
is starting to "flat top". This is at a level of 26-27dBm (0,5W) PEP.  
Below this point all IM products are more than 60-70 dB down and not seen  
on the spectrum analyzer at 100Hz bandwidth. This is the same when I  
measure Hermes (Beta) that use the same technical solution as Pennylane.

I do not understand your description of what you observe on the analyzer.  
How do you see that Penny is not as clean using 2-tone test as it is on  
SSB or AM? When you test with 2-tone the Mode should be SSB. If in AM, the  
spectrum will show the carrier + both sidebands.

Try running the Level at 0 dB and reduce the Power. Also the drive in PA  
Setting influence the output spectrum. Avoid using settings between 38,8  
and 40 dB. Use the default 700 and 1900 Hz as modulating frequencies. And  
Compressor must be OFF.

What version of PSDR are you using? I think Phil once mentioned that some  
versions had problems. I am at the moment using v2.2.3(W5WC 12/19/11)  
wcpAGC.


Are you sure you are not overdriving the spectrum analyzer?

73, Kjell



På Thu, 26 Jan 2012 03:33:34 +0100, skrev FRANCIS CARCIA  
<carcia at sbcglobal.net>:

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