[Elecraft] AGC 8 volts? (Nope)

[Mike Markowski]

W3FPR - Don Wilhelm wrote:
> No, I do not believe the last digit on your measurement [...]

I didn't think so.  :-)  (But now you know where my earlier incorrectly
remembered number of 7.92 V came from.)

> my guess is: because your 8 volt rail is
> 0.12 volts low, you should initially set the AGC threshold so the voltage is
> about 0.06 volts lower than specified in the manual (set to 3.74 volts).

Thanks, Don, hearing it explained makes perfect sense.  Debugging on my
own in the midst of building, though, is difficult so I greatly
appreciate the pointers!

> I do recommend optimizing your AGC Threshold after you have the K2 up and
> running on all bands.  [...]  Further
> refinements/adjustments are possible, but I cannot go into all the details
> in a reasonable length reflector post.  [...]

When I get to this point in the build I'll probably bug, er, contact,
you off-list for the particulars if that's ok.  I'm sure once the
building becomes part of history I'll be glad to have an excuse to tweak
and otherwise mess around with the K2.  But for now, back to Step 2 in
the RF assembly.  Last night I finished installing the first armload of
resistors.  Tonight will probably be the similarly long list of
capacitors.  And then, oh no, on to winding some toroids.

Many thanks,
Mike  AB3AP
Avondale, PA

>>-----Original Message-----
>>
>>Thanks very much, Don, for your ideas.  My email had faulty numbers as a
>>result of a faulty (human!) memory.  I remeasured voltages just now at
>>Control Board locations you measured and got these results:
>>
>>   - U2 pin 5: maxes out at 3.792 V    if you believe that many
>>                                       significant figures.
>>
>>   - P1 pin 6: 1.2 mV
>>
>>   - U4 OUT:   7.88 V ... the culprit?
>>
>>I will disassemble and check my solder connections you mentioned.
>>
>>Thanks and 73,
>>Mike  AB3AP
>>Avondale, PA