[Elecraft] K2 Op Gen Q's

[Kevin Cozens]

At 11:00 AM 02/02/2002 -0600, Tom Hammond N=D8SS wrote:
>Sean:
>>I noticed a few characteristics of the K2 that I wonder if it is normal.
>>First, the speaker audio sounds good but I find I am running the audio=
 gain
>>at 12 o'clock and on weak signals and/or using the passband audio filter I
>>will turn the gain up all the way.  It seems like I need 2 watts of audio
>>rather than just 1 watt as per spec.  There is no distortion of audio even
>>at full volume that is great but it is at full volume.  Any comments?
>
>Is this with the case buttoned up? Or with the top off? Putting the top on=
=20
>the case makes a significant difference in level!

I recently had a similar problem with my K2. The volume was ok at first but=
=20
then dropped. After the volume had dropped, I was running with pre-amp on,=
=20
full RF gain, and full volume and yet there seemed to be little volume.

Once while adjusting C22 I noticed a return to better volume for a while=20
but it eventually dropped again. Poking and prodding eventually tracked=20
down the problem to a bad solder joint on the control board for R19.=20
However, looking at the schematic to see why the volume would be affected I=
=20
noticed that R18 and R19 are in the audio amplifier area. I also noticed=20
that they should be jumpers and not resistors since I didn't have the=20
optional audio filter board in my K2.

I removed the 2k2 resistors at R18 and R19 on the control board with wire=20
jumpers.  When I next turned on the K2 I had LOTS of volume out of the=20
speaker even with the top off. I didn't need to have the pre-amp on and the=
=20
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=
=20
K2 but have re-done one mod, done the grounding mod on the 4.9MHz Xtal=20
chain, reseated some of the components, and realigned the radio to get more=
=20
familiar with the K2).

If you have low audio, Sean, I suggest you check the R18/R19 spots on your=
=20
control board. This might be a good addition to the troubleshooting manual.=
=20
ie. If your speaker volume is low and turning the volume control all the=20
way up does not seem to help very much, verify that jumpers were installed=
=20
in the R18/R19 locations on the Control board.

Hope this helps, Sean.


Cheers!

Kevin.  (http://www.interlog.com/~kcozens/)

Owner of Elecraft K2 #2172        |"What are we going to do today, Borg?"
E-mail:kcozens at interlog dot com|"Same thing we always do, Pinkutus:
Packet:ve3syb@ve3yra.#con.on.ca.na|  Try to assimilate the world!"
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