[Elecraft] K1 crystal grounding

[Geoffrey Mackenzie-Kennedy]

Carl,

FWIW when building crystal filters I have found that soldering the grounding 
wires to the bottom of the cans provides better isolation between crystals 
than to the top of the cans IF there is proper shielding in place 'below 
deck' and the crystals are laid out side by side in a straight line. If 
there is no shielding in place 'below deck' and if the filter crystals are 
not placed in a straight line there might not be any improvement gained by 
tacking to the bottom vs the top, since the crystal to crystal unwanted 
coupling could well be less than the unwanted coupling taking place 
elsewhere in or around the filter. The use a single wire and one ground 
connection to ground two or more crystal cans should be avoided if at all 
possible.

IMHO I would leave your K1's filter crystal grounds as they are to avoid 
reheating the crystal cans.

In my K2 I have the KSB2 installed and I did tack separate ground wires to 
the bottom of the crystal cans when building it, but the leakage around the 
filter masked any improvement in my case..

73,
Geoff
GM4ESD


WA7CS wrote on Thursday, January 03, 2008 3:33 PM

> I'm currently building the K1.
>
> When I built a K2 a few yers ago, there was an errata sheet or a builder
> alert, etc. advising that crystal grounding should be done near the bottom
> of the crystal can as opposed to the top of the can.
>
> I can't seem to find similar advice for the K1.
>
> I've already installed all of the crystals with the ground wire soldered 
> to
> the top of the cans.  I'm considering going back and tacking the ground 
> wire
> to the sides/bottom of the crystal cans.
>
> Also, in the K2, I seem to recall that all of the crystals were grounded
> together with a wire along the top - no similar instruction for the K1.
>
> Should I do this, or is any potential benefit not worth the effort/risk?