[Elecraft] K2 IF alignment

[Don Wilhelm]

Tom,

Yes, you have a receive problem.  Make a quick visual check of a few 
things first.  T7 should have the green winding next to the crystal 
filter and the red winding next to the IF amplifier.
Check the orientation of the IF amplifier and the product detector ICs.
Check orientation of diodes D6 and D7 as well as all the diodes in the 
T/R switch - use the Parts Placement diagram in the back of the manual.

Check for 12 volts on the collector (case) of Q21 and Q22.  If not 
present, look for a soldering problem or inadequately stripped and 
tinned leads of T6 (preamp-Q21) or RFC11 (for Q22).

If that inspection does not reveal anything helpful, you will probably 
have to resort to Receive Signal Tracing.  Build up the RF Probe (parts 
with the K2 kit) and the crystal oscillator shown in the Troubleshooting 
appendix of the manual.  The XG3 does not have enough output for the 
signal tracing.  The crystal frequency is not critical, but must be at a 
frequency the K2 can receive.  An inexpensive 'computer' crystal will 
suffice.

Once Signal Tracing has isolated the failure to a specific stage, we can 
help localize the failure to the component level.

73,
Don W3FPR

On 5/4/2013 10:49 PM, Tom Field wrote:
> I'm at the building stage of IF alignment for the K2 I'm supposed to hear a
> signal around 7000 kHz. I hear nothing. I've done the 40 meter filter
> alignment and checked with an XG 3. The tuning seems spot on, but I only
> hear the X3 when set t0 50 uVolts. The 1uvolt signal doesnt' get through.
> Any ideas
>