[hpsdr] FLEX SDR1000 PA IMD problems

[Jay Johnson]

Hello Paul, I too have run into this with using my SDR1000 PA with
Penelope as the driver.  What I have found here is that I cannot run
more that 100 to 125 mw max out of Penelope for voice, typically
something less than 100 mw on average for SSB voice.  This results in
less than 100 watts out of the SDR1000 PA, but it is much cleaner.
Penelope by itself is quite clean on the RF output well pass this self
imposed limitation.  Running a two tone test and oscilloscope sampling
the RF out will show the results.

Jay
n2mga


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Message: 11
Date: Fri, 07 Jan 2011 15:21:29 +0000
From: Paul Fletcher <paul_fletcher at me.com>
To: hpsdr at lists.openhpsdr.org
Subject: [hpsdr] FLEX SDR1000 PA IMD problems
Message-ID: <F3DE9CD76E044CFFA21276E4EE0D90C9 at shackPC>
Content-Type: text/plain; format=flowed; charset=iso-8859-1;
	reply-type=original

Some of you might have realised that I'm in the process of employing an
SDR1000 100W PA in my HPSDR setup. It is all connected and working and I've
been reminded of why I stopped using the SDR1000 - transmit IMD (not very
good to be polite). The PA has also been re-biased as per the change note
but IMD on 40m is objectionable.

Does anyone have any experience of modding this PA to improve performance?

Regards,
Paul.

 1294445671.0