K1 crystal grounding

[WA7CS]

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?

Carl

WA7CS

[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?

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[bill KE5KWE]

I am currently building a K2 and there is no such caveat.  Each crystal is grounded, individually per instructions.  Some are tied togeather, others are grounded on the top and others are grounded on the side or bottom.  But I would follow the instructions in the manual and not improvise.

Good Luck, Bill KE5KWE

Geoffrey Mackenzie-Kennedy wrote

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?

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