K2 Test and Alignment Part I - MIA ATT & Preamp Relays

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K2 Test and Alignment Part I - MIA ATT & Preamp Relays

Robert Brown-11
Just completed Test and Alignment Part 1 - and was
glad to see K2 4663 power-up without any sign of
smoke.  Going through the various tests, however, I
received positive LCD feeback when the ATT/Preamp
button was pressed - but no corresponding chatter from
the relays.  Every other function I have checked, has
worked perfectly as indicated.  Having looked at the
schematic, I see that K1-6 and 7 are the relays that I
should be hearing when ATT/Preamp is pressed.

Before attempting to replace one or both of the
relays, I unmounted the control board (where some of
my initial test readings had been mildly suspect -
while everything on the front panel board checked out
perfectly), and I am seeing somewhat low readings on
U6 and U8's various pins.  My ability to check
collector readings on Q1 and Q2 is constrained by the
limited range of my ohmmeter (must do something about
that). From my review of the K2's schematic, it would
appear that Q2 could be at issue (as the 8R signal
appears to play a role in K1 6 and 7's operation).

As I'm writing from Prague in the Czech Republic, I'd
sorely like to figure this one out from here - and
would welcome any insights from those of you on the
reflector.  Replacing one or both of the relays would
be reasonably easy, but I wonder if the problem lies
elsewhere.  

73 de Bob Brown, N1CVX
KX1 # 874

P.S.  As I generally read these comments in digest
mode, please copy my private address as well.
Greetings, as well,  to W2RBA from a former student.
Joe was responsible for getting me licensed in the
early 80's (KA1JVE).



               
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