[Elecraft] Freq probe

[Vic Rosenthal]

Francis Belliveau wrote:
> 
> I find the need to have the top cover on interesting.  As I recall there was
> a note published about removing the frequency probe before buttoning up the
> K2?  Something about mixing or harmonics being introduced that got noticed
> during the early days of K100 production.

One possible problem is that the third harmonic of the BFO is around 14.9 MHz
and this could sneak through the 20 m filter, especially if the amplifier is
installed (or if you use an external amp).  The recommended procedure is:

1) Plug the probe into TP1 and put the cover on.
2) Run CAL PLL.
3) Remove the cover, move the probe to TP3, put the cover back on.
4) Run CAL FIL.
5) Remove the cover, remove the probe, put the cover back on.

I listened to the 14.9 MHz signal in another receiver with the probe in TP3 and
with it removed.  It was much louder with the probe in place.  I didn't have the
equipment to actually measure the strength of the spur compared to the desired
signal, so I left the probe out!

73
Vic K2VCO