David,
The only other thought I have is that perhaps the KPA100 PA transistors
are not operating at exactly the right point of their characteristic
curve. The only thing that will change the portion of the curve for the
PA transistors (i.e. the operating point) is the bias. The bias setting
given in the KPA100 manual is good for most applications, but that does
not say it cannot be optimized for a particular set of transistors used
in a specific application. I would suggest that you alter the bias
setting *slightly* on either side of the manual suggested setting to see
if you obtain any improvement. Good luck with your experiments.
73,
Don W3FPR
dberkley wrote:
Don,
At first I thought your suggestion didn't affect anything since I already
had dressed the leads fairly well. However, in bypass mode (less than 10
watts) the IMD is now back to -30 dB. Also, after running for about 15
seconds, the IMD at 25 watts now drops to about -27 dB.
So there is now a noticeable difference between bypass and KPA100 mode and,
I suspect, a difference in my SSB performance as well. Any other good
thoughts like that one?
Tnx and 73, David
K2MUN
Don Wilhelm-4 wrote:
David,
The KPA100 can be coupling back into the KSB2 option.
Remove the right side panel and tuck the ribbon cable and speaker cable
up into the space at the top of the KPA100 instead of letting it dangle
near the KSB2 board.
I will not guarantee that it will help, but it often makes a difference
on SSB, and can also help on data modes.
_______________________________________________
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com
