K2 Pre-amp and att

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K2 Pre-amp and att

Nick G3RWF
Seem to have a problem. Most gain is with no pre-amp (sounds fine). Some attenuation with att on and more attenuation with pre-amp on. Have checked out T6 - seems soldered OK. Any thoughts please?
Many thanks to those who responded to my filter post - very helpful indeed. 73 Nick G3RWF
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RE: K2 Pre-amp and att

Don Wilhelm-3
Nick,

Are your getting voltage to the collector of Q21 (measure on the case - 11
to 12 volts)?  If you have no voltage there, check T6 again and R74.

Be certain the leads of T6 are the correct color - leads 1 and 3 must be of
the same color.

If all is well above, then check R75, R76, R77 for correct values, check
them for good soldering and check the soldering at the leads of Q21. Also
check R72 and R73 as well as C142.

If exerything there checks out, then the relay is next to check - turn the
K2 on and set the preamp on.  Then turn the K2 off and check continuity with
your ohmmeter between K17 pins 3 and 4 plus pins 7 and 8.

If all checks are good so far, the preamp should work.

73,
Don W3FPR

> -----Original Message-----

>
> Seem to have a problem. Most gain is with no pre-amp (sounds
> fine). Some attenuation with att on and more attenuation with
> pre-amp on. Have checked out T6 - seems soldered OK. Any thoughts please?
> Many thanks to those who responded to my filter post - very
> helpful indeed. 73 Nick G3RWF
>
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