[hpsdr] AGC problem

[Rod Brink]

During the three weeks I've had my Hermes I've been experiencing intermittent problems with AGC.  Sometimes the receiver performs as if there's no AGC action at all.  This was first noticed when strong signals came blasting through, so loud as to cause distortion in the speaker.  With a signal generator connected to Rx input I was able to confirm no (or very little) AGC action.  The problem is highly intermittent - it occurs only occasionally and can be "fixed" by resetting the database and then importing it again.  The database itself remains intact but it appears that whatever is mirroring it into PSDR is getting corrupted.  

I have AGC slope set to 0 and Fixed Gain = 20dB.  I've measured audio level on a scope with a signal generator feeding into the receiver.  When operating correctly (which is most of the time) I see audio increasing in amplitude until about 70dBm, thereafter flattening out as signal level is increased.  When the failure occurs the audio level continues to increase with increasing RF until severe distortion occurs.  These tests are conducted in SSB mode with the signal generator frequency set 1 kHz into the audio passband.

I'm running W5WC RX2 v2.2.5.0 PSDR under Windows xp.  The machine is an older Dell and CPU usage is about 50% for single receiver operation.  I've seen the same behavior on a newer, faster machine running Windows 7.

I'm wondering if anybody else has seen this problem.

73,
Rod, KQ6F
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