[Elecraft] [K2] lack of sensitivity...?

[Gil G.]

Thank you everyone for your suggestions.

I did have one bad solder joint on TR7, fixed it by soldering one lead on top. Maybe the problem is related to that.
Tuning L34 doesn't seem to do much of anything. There was no 3.3pf capacitor for C22 on the RF board, but I had one 2.7pf left over after finishing, so I assumed I had to use that..
I did try to compare the K2 with the K1 without the ATU, it does make a difference, now it is closer (with preamp on). Maybe I'm being too picky. I was assuming the K2 would run circles around the K1.
Don, what kind of additional data can I gather that would help make a diagnosis?
I do not have an RF signal generator, but I have a K1 and a dummy load.
It is peculiar that the 20m band is the most affected… Could filter setting be the cause?
I do have spectrogram on my iPod, but the interface is different than on the PC version, not usable for filter adjustments.
(I use a Mac…)

Gil.
--
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On Aug 30, 2012, at 10:16 AM, Don Wilhelm wrote:

> Gil,
> 
> It is difficult to make a definite answer without some additional data.  Yes, the atu in the K1 could make some difference, but not an extreme difference on receive.
> 
> The most likely guess is that you missed a solder connection somewhere in the receive section of the K2.  Go over the board with a suspicious eye.  The receive portion of the K2 is between the MCIO IC (in the middle of the board) and the front panel.
> 
> The fact that you have full transmit power on all bands says that the problem is *not* in the bandpass filter nor the Low Pass filter.
> 
> 73,
> Don W3FPR