Hello. I have recently started to see a problem with a Corsair II I
acquired. When I got it from the fellow the audio seemed a bit hissy (I
have a Corsair II available to compare to). Not exactly what I like,
and I didn't really feel much like using it very much, but did not proceed
to address its inadequacies over the winter (too busy with house
renovations).
Last weekend I noticed when I wanted to listen to a local net for a few
minutes
it was even worse, and had seemed to become harsher. Not useable at all.
So last night I began to just check out things - checking switches etc.
and I noticed that when moving the adjustment pot for the keyer speed that
the noise could be made worse, better, and maybe even non-existent at
different points in the pot's degrees of travel. I even used it for a
couple qrp cw contacts with the cw filter in and out, and with bandpass
width
filter adjustments. Worked fine and was OK to listen to - even to a weak
RST 229 sig that was maybe .5kc or less from a stronger station. Yes, it
does receive very well, cw filter engaged or not, when the noise is gone!
Thankfully at least I see to now make the noise gone (it seems) if I can
find the sweet spot in the pot's range.
Still, would like to fix this. I contacted Ten-Tec service this morning
and they feel this might be a bad bypass cap or bad ground, probably not
what they can diagnosis for a field fix. I'd rather not, if I can avoid
it, send it to Tennessee, as freight there and back from Toronto can cost
a bit.
If anyone has experienced this, I sure would appreciate hearing about it.
I am thinking of disconnecting the keyer pot and or checking all relevant
board interconnect pins/sockets etc. in terms of wiring obviously, as well
as what might be suspect cap solder connections. Still, it is funny that
the pot (or what it controls, roughly) can introduce non-linear (almost
random control of) noise into all audio (CW, SSB, SSB-Reverse).
TT tells me the processor involved shares duty of the frequency counter
and the keyer. If it is socket mounted I might reset it into the socket.
I'd like to fix it in the end, but if some short term solution (isolate
keyer speed control pot) fixes it for instance I would be happy using an
external keyer until maybe next time I am in the USA and can ship it to TT
from a place closer and cheaper at least from the one point.
Anyhow, that is data for the Corsair II and one
symptomatic problem and apparent 'source'. More if and when I find out.
In any case, when it is working fine I now am once again aware it is a ne
plus ultra rig, so somehow
and time it will be fixed. That and the K2 will be 'wrung from my lifeless
hands' only.
73 de
Brien Pepperdine
Amateur Radio Station VE3VAW
Toronto, Ontario Canada
ARCI QRP #8773 - NORCAL QRP "ZOMBIE"
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