[Elecraft] K2 no transmit power

[Rich Haendel]

After checking once again for shorts, wrong parts, etc I still haven't =
come up with an answer why I can't get TX power on any band.  I have =
looked and found the following:  =20
1.   EXCEPT  when using the internal frequency counter set up from the =
CAL menu, there is NO voltage on the drain of Q24 which supplies RF =
injection to the XMIT mixer.  Is this normal.?   I am checking this with =
the key in CW mode,  key down or key up.  =20

2. TUNE mode does not operate as in the manual at all.=20

3. There is no voltage on Q24 ( nor any power output) when in TUNE mode =
either, which normally I would expect. In this case, the keyer should =
not be needed.  Is this correct?=20

4. Collector voltages appear to be normal on all transistors from the =
predriver to the final amplifiers. =20

5. Checking with a scope, there does not appear to be any RF drive from =
any low level stages, that's why I traced the lack of signal back to =
Q24.   Q24 does operate normally when in the mode described in item 1 =
above.=20

6. When I am in OPER mode (not test) and I attempt to key the K2, I get =
a periodic burst of carrier for a few milliseconds.  It looks like power =
turndown is shutting off the rig at the trailing edge of the short =
burst.  Checking V-ALC from the emitter of Q8 on the control board shows =
no voltage at all except when in the condition in item 1.  I thought =
incorrectly that this is supposed to be turndown for too much TX power =
coming from V PWR. =20

Anyone have any ideas? =20


Rich W3ACO   S/N 4023






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