[Elecraft] K2 Op Gen Q's

[Tom Hammond NØSS]

Hi Kevin:

If the serial number of your K2 is one of the rather low numbers, there's a 
chance that R18 & R19 were installed at parts of the instruction manual at 
that time.

I just checked the (Field Test) manual for my K2 (S/N 00008, which has what 
I consider to be barely ample audio) and found that 1.2k resistors were 
installed for those two resistors in the Field Test versions of the rig, 
and it's possible that 2.3k R's might have been used in the first series of 
production units which came out.

I cannot comment uopn this with any degree of certainty however, because I 
don't have a copy of the Rev A version of the K2 manual available to 
confirm/deny it. But it's a possibility.

>Once while adjusting C22 I noticed a return to better volume for a while 
>but it eventually dropped again. Poking and prodding eventually tracked 
>down the problem to a bad solder joint on the control board for R19. 
>However, looking at the schematic to see why the volume would be affected 
>I noticed that R18 and R19 are in the audio amplifier area. I also noticed 
>that they should be jumpers and not resistors since I didn't have the 
>optional audio filter board in my K2.
>
>I removed the 2k2 resistors at R18 and R19 on the control board with wire 
>jumpers.  When I next turned on the K2 I had LOTS of volume out of the 
>speaker even with the top off. I didn't need to have the pre-amp on and 
>the volume control was turned down to about 1/3.
>
>I don't know why R18/R19 had 2k2 resistors installed (I bought a pre-built 
>K2 but have re-done one mod, done the grounding mod on the 4.9MHz Xtal 
>chain, reseated some of the components, and realigned the radio to get 
>more familiar with the K2).
>
>If you have low audio, Sean, I suggest you check the R18/R19 spots on your 
>control board. This might be a good addition to the troubleshooting 
>manual. ie. If your speaker volume is low and turning the volume control 
>all the way up does not seem to help very much, verify that jumpers were 
>installed in the R18/R19 locations on the Control board.

73,

Tom Hammond   N0Ss