K-2 troubles, beginning on p.64 of manual

[ni0c]

I'm looking for suggestions and likely goofs on my part that might be the cause of the following symptoms with my brand new K2:

The receiver appears dead to an antenna input.  I have installed the 160m receive kit "un-module" (whose function seems only to replace the jumper at W-1.) I also installed C13, C14 and C75 per the un-module instruction sheet for incorporating the re-work eliminators in a new build K2.  I also installed the un-module for the DSP audio filter on the control board.

Here's exactly what happens:

I do hear noise from the receiver, also I hear the "weak internally generated signal near 7000 KHz."  However, when I adjust L34 to try to peak the signal strength, very lttle if anything happens.  Charging ahead to hook up an antenna (who can resist at this point) there is no perceptible change in receiver noise when I connect my HF-2V antenna.  Changing L1 and L2 doesn't do anything at this point, either.

Any suggestions would be appreciated.  Thanks in advance,

73,
Chuck  NI0C
 
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[Don Wilhelm-3]

Chuck,

You mentioned the 160 meter rework eliminator, and that begs the following
question:
Did you install the rework eliminator headers for the K60XV option?  If so,
did you change C71?  Did you add D19 and D20?  If you answered yes to all
those questions, then be certain the K60XV unmodule is 1)-plugged in, and
2)- contains the 4.7pf capacitor and have you set D19 = y in the K2 menu?
(it must be on).  If you answered ALL the above questions 'NO', then be
certain you have C6 and W6 installed on the RF Board (C6 is on the bottom)
and that C71 is 82 pf.

After that preliminary is taken care of, if you still have problems, you may
have to do a bit of signal tracing.  First check out the easy to do 'Quick
and Dirty Signal Tracing' by Tom Hammond, you can find that documented on
the Builders Resource page of the Elecraft website.  That may help you to
isolate the area that is giving trouble.  If not, you may have to resort to
the receiver signal tracing steps shown in the K2 manual (build the RF Probe
and the oscillator if you do not have a signal generator and 'scope).

You will most likely find that you have a soldering problem somewhere -
check the soldering, then re-check the soldering and when that is done,
check the soldering.

The second most common cause of failure is misplaced components.

Signal tracing is the quickest method to lead you to the area of the problem
and from there, the schematic is a guide to showing how that area is
connected and the component values that should be present, allowing you to
quickly find the problem component.

73,
Don W3FPR

> -----Original Message-----
>
> I'm looking for suggestions and likely goofs on my part that
> might be the cause of the following symptoms with my brand new K2:
>
> The receiver appears dead to an antenna input.  I have installed
> the 160m receive kit "un-module" (whose function seems only to
> replace the jumper at W-1.) I also installed C13, C14 and C75 per
> the un-module instruction sheet for incorporating the re-work
> eliminators in a new build K2.  I also installed the un-module
> for the DSP audio filter on the control board.
>
> Here's exactly what happens:
>
> I do hear noise from the receiver, also I hear the "weak
> internally generated signal near 7000 KHz."  However, when I
> adjust L34 to try to peak the signal strength, very lttle if
> anything happens.  Charging ahead to hook up an antenna (who can
> resist at this point) there is no perceptible change in receiver
> noise when I connect my HF-2V antenna.  Changing L1 and L2
> doesn't do anything at this point, either.
>

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[ni0c]

Success already!  Thanks to Don!

My problem was caused by failing to install the "W6" jumper and C6 on the RF board.  (I had skipped these steps, because they were referenced in the literature for the re-work eliminators).  The fault lies with me, not the instructions-- I should have paged through the manual more carefully to review my steps before firing up the rig.

At any rate, I couldn't be more pleased.  I just reconnected my antenna and heard some DX signals on 40m CW.  I can go to work now, not fretting about my new toy.

73 & Thanks again, Don!

Chuck  NI0C
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