Posted by
G3VVT on
Oct 23, 2004; 12:14am
URL: http://elecraft.85.s1.nabble.com/Mod-for-more-AF-gain-on-K2-tp371029p371035.html
Another alternative to fit the 386 in the place of an LM380 audio amp in the
K2 would be to cut the print on the affected pins and fit insulated wire
straps to change the print layout. Have not checked the 386 pin out to confirm
the details, but pin 5 would need isolating from ground on the top/component
side of the control board and on the underside 4 lines of print to pins 6, 7, 8
would need to be cut with something like a Dremel tool. New insulated wire
straps could then be added to change the print to that required for the 386.
My own K2 (serial no. 4168) does not suffer from low audio and is run with
the AF gain control at 1/4 to 1/3 rotation from minimum for most uses with
either the normal internal speaker or a single earpiece headset/electret mic
that I use with the K2. Is mostly used for SSB with OP1 filter in use, only
resort to using the "drum" (CW) in extreme circumstances to complete a contact
when condition are poor. I would be more susceptible than many to the effects
of low audio after loosing most of my hearing on one side after an accident at
work and the remaining ear down to telephone bandwidth only.
Is the low audio complaint applicable only to early K2's, the effects of
narrow filters in CW reception or is it a random effect caused by gain variation
of active components?
Regards,
Bob, G3VVT
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