[Elecraft] K2 "not hearing"

[Don Wilhelm]

Gil,

The sidetone signal does inject into the audio amplifier differently 
than the receiver audio.

The first thing to check is the 'dumb stuff' - did you remove the KAF2 
or KDSP2 and fail to put it back in.  That would create a break in the 
audio path.  Bid you remove the KSB2 and/or the KNB2 and not re-install 
them (or offset the pins in the headers) - that would break the receive 
path at the IF.

If those things above do not restore a working receiver, try the Quick 
and Dirty Signal Tracing method first.  You can download the document 
from the Elecraft website or you may also find it at Tom Hammond's (Tom 
is the author) website www.n0ss.com

73,
Don W3FPR

Gil Gibbs wrote:
>   I was going along fine on all my preliminary checks on my K2 
> "revival", got the sidetone going OK, then started in on the secondary 
> checks. To my dismay, I can't hear anything on any band, and I'm now 
> wondering if I let the smoke out of something in the receive. Not being 
> very good at tracing the schematic, I can't tell if the sidetone uses 
> the same circuit to the headphone plug that the receiver does or not.
>   Could I have fried a diode someplace, with that one problem of getting 
> the KIO2 wires "backward" when I wasn't paying attention, in the course 
> of setting up for the KAT100 addition?