[hpsdr] Penny[lane] V1.4 firmware issue - progress made

[Paul Fletcher]

Hi all,

I have been making progress tracking down my distorted TX audio problem and 
I can now make the problem appear or disappear at will. I'm none the wiser 
as to why this happens but it is totally repeatable.

Setup is 1.9.3.5 PowerSDR dated 9/18/11, Metis and Pennylane V1.4 and 
Mercury V2.9

Basically it appears related to the distance (physical) Mercury/Pennylane 
are installed away from Metis. I get the same symptoms is Metis is installed 
in J1 or J6. Starting with Pennylane installed furthest away from Metis and 
Mercury in the next slot the distortion is present. If I switch the position 
of Pennylane and Mercury it gets less. If I leave Mercury where it then is 
and move Pennylane another slot closer to Metis the distortion gets less 
again. Moving Pennylane closer to Metis after this without moving Mercury 
shows no further improvement.

If I then move Mercury 1 slot closer to Metis and install Pennylane between 
Mercury and Metis the distortion is almost gone.

If I move Mercury 1 more slot closer to Metis and again install Pennylane 
between Mercury and Metis the distortion is gone completely.

I performed this test with Metis installed in slot 1 and slot 6 and the 
pattern is the same.

Hopefully this is clearer than mud!

At this stage I'm not sure if there is a timing issue somewhere or if there 
is a problem with the backplane. Equally I'm not sure why this wasn't 
apparent with V1.3 firmware but there is definitely something different 
going on.

73 Paul M1PAF