[Elecraft] K2 Volume and a plead to Elecraft

[Don Brown]

Hi

There are several things that can affect the setting of the AGC =
threshold. The forward drop of D1 and the actual voltage on the 8 volt =
supply and the total open loop gain of the RF and IF amplifiers. The 3.8 =
volt setting is a nominal setting that will get the radio working but =
may not be the best setting for a particular K2. If I remember the =
procedure right. Connect the K2 to an antenna and tune to a quiet band =
then adjust the R1 pot on >3000 s/n or adjust the value of the fixed =
resistor R1 on <3000 s/n. The correct setting is just when the band =
noise does not change when the AGC is turned on and off. After making =
the adjustment reset the S-meter low and high settings. This should get =
the AGC working right and if that is the reason for the low volume then =
that should correct it.=20

Another reason the volume could be low is a miss-wired external speaker =
jack or the wires reversed in the speaker plug that connects to the RF =
board. If the AF signal is swapped with the ground then the audio will =
be low.=20

There have been speakers damaged in shipment where the frame is bent =
slightly out of alignment. This will usually cause a distorted or =
rubbing sound but could also cause low audio. You can try gently bending =
the frame by prying with a screwdriver between the magnet and frame. Try =
it at each quadrant around the speaker to see if it improves. If you =
find a place that improves the sound then apply a little more force to =
make the 'adjustment' permanent. This bent frame problem can also be =
caused by over tightening the speaker mounting hardware.


Don Brown
KD5NDB =20



SNIP
   Most respondents talk about adjusting the gain on R1...but it seems =
to me there are far to many of us out there who do not understand why =
two identical K2's can have different volumes when R1 is set to 3.8v on =
both. Also, what are the pros and cons of going beyond the manual's =
suggested setting? Wayne and Eric had to have a reason for suggesting =
3.8v.=20

  SNIP

  73/Tim NZ7C=20



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