[Elecraft] AGC 8 volts? (Nope)

[Mike Markowski]

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

W3FPR - Don Wilhelm wrote:
> Mike,
> 
> Are you measuring on the correct pin, and do you have the RF GAIN at full
> Clockwise rotation (Max gain)?
> 
> I see no indication that 8 volts should be measured for the AGC.  The manual
> page 47 calls for setting the AGC Threshold pot to achieve a voltage of 3.80
> volts as measured at Control Board U2 pin 5.  If you are not able to adjust
> that high, check the soldering of Control Board RP6 and pot R1 carefully,
> make certain the resistance from Control Board P1 pin 6 to ground is close
> to zero (if it is higher, check the connectors), and lastly check the
> voltage available at the OUT terminal of Control Board U4.  There are no
> active devices in this part of the circuit - it is just a resistive voltage
> divider with two legs and driven by the 8 volt supply rail.
> 
> 73,
> Don W3FPR
> 
> 
>>-----Original Message-----
>>
>>Last night I completed what the manual calls "Assembly, Part I" of the
>>RF board.  What a great feeling to power up the K2 to check out the
>>control and display boards, and to hear the relays click and see the
>>menus working.  So far the only thing that hasn't quite reached
>>recommended values is that my control board AGC voltage maxes out at
>>7.92 V rather than the 8 V mentioned in the manual.  I'll have to search
>>& see if anyone has reported a similar thing.
>>
>>Anyway, once the K2 is up and running I'll be glad to check into the net
>>from Delaware once I make a portable dipole for 20m.  Maybe another
>>month, plus or minus a little.  In my year and a half on the air as a
>>ham I've never checked into a CW net, though, so that'll probably be an
>>adventure itself!
>>
>>Mike  AB3AP
>>
> 
> 
> 
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