[Elecraft] Spurious signal after k2 click mod

[Mario Lorenz]

Am 29. Feb 2004, um 07:46:46 schrieb Vic Rosenthal:
> Dale Boresz wrote:
> 
> >On what frequency were you operating when the spurious signals were 
> >observed?
> 
> 14.026.  KT5X heard them down about 40 db from the main signal, about 
> 550 Hz on either side, at power levels of 5 to 100 watts (so it isn't 
> related to the KPA100).  After our QSO, I confirmed their presence by 
> transmitting into a dummy load while listening on my TS850s.  It was 
> possible to hear them quite well when the signal was S9 on the TS850s.
> 
> I've since verified that the mod was done correctly, that D36 is not 
> backwards, etc.  The thing that bothers me is that I can't be 100% sure 
> I didn't have this problem before doing the mod.

I recently had the chance to take a quick look of my  K2 on a spectrum
analyzer, and I have seen similar spurious emissions there, all approx
in the -40 dB range, in some cases at about +- 600Hz, in some cases on
other places. For example, on 80m, a spurious signal at 4MHz was clearly
visible on the analyzer, which obviously is one of the MCU oscillators.
    
I did not have the time to look into that in detail, in particular if it
was really present or some form of measuring error, so I did not give
that much about it and decided to look into that matter once I get access
to a spectrum analyzer again.
	
I certainly have not done the keyclick mod yet, so I do not think this
behaviour has anything to do with that mod.
	  
Vic, have you got the counter probe still hooked up? I vaguely remember
Elecraft in their KPA100 manual suggested that it better should
be removed, because leaving it installed could produce spurious emissions
in some case.
	     
Mario

-- 
Mario Lorenz                            Internet:    <ml@vdazone.org>
                                        Ham Radio:   DL5MLO@OK0PKL.#BOH.CZE.EU
Remember: In god we trust -- all others we polygraph.
  -- Jim Christy, Assistant for law enforcement, US Air Force