[Elecraft] SSB Audio Problems

[Paul Wilton]

Thanks for all the advice received so far from everyone on the list.

A couple of clarifications
a)   I do not believe I have an A-C field problem.  I will double check 
everything but I didn't have anything within close range.

b)  I don't also believe I have an RF induced problem since I am using a 
well shielded dummy load

c)  Re the power control, the behaviour I am seeing is occurring AFTER I 
hit the PTT.  The output of pin 6, U2 (PWR CTRL) on the SSB board seems 
to drift upwards from 1 to 5 volts pretty slowly.  However, if I turn 
the power control down, it drops very quickly.  Perhaps this is the 
intended behaviour.

d)  Annoyingly the raspy CW seems to be intermittent - it has now has 
stop misbehaving now that I have time to look at it.  I intend to listen 
to the BFO/VFO on another receiver next time it happens.

Thanks again for all the advice.

Paul
M1CNK

Message: 19
Date: Sat, 12 Nov 2005 12:59:58 -0800
From: "Ron D'Eau Claire" <rondec at easystreet.com>
Subject: RE: [Elecraft] Problems with SSB Audio
To: "'Elecraft Discussion List'" <elecraft at mailman.qth.net>
Message-ID: <000101c5e7cc$0addcd60$c5ddfea9 at RONPORTABLE>
Content-Type: text/plain;	charset="us-ascii"

"Raspy" is often the description given a signal from a K2 that is sitting
too close to a transformer so the a-c magnetic field modulates the VCO. If
you have a power supply, desk lamp with a transformer built in, or any other
transformer operated device nearby, try turning it off and see if your
signal clears up. 

If so, there's a mod for the K2 that will dramatically improve its
resistance to magnetic field effects. See www.elecraft.com for details.

About the power control, are you expecting it to go to work before your
transmit? It won't! The power control sets the "requested" output. The
actual output doesn't change until you transmit again, and transmit long
enough for the power monitor to note the actual output and adjust the
circuit to match the "requested" level you set with the POWER control. It's
not uncommon for ops to turn on a rig and notice that even though it's been
in receive for half an hour, when the hit the key the power stays at zero
for the first dash or several dits, depending upon the keying speed. That's
because the power control circuits are only then getting some RF to work
with to set the actual power output correctly. 

Ron AC7AC