[Elecraft] OT - Soldering Crystal Cans

[Stuart Rohre]

The soldering of ground leads to xtal cans is not a big complicated deal,
and is easily done even if you have not soldered much sweat soldered work
before, which is what you do here:

The side soldering on the xtal cans of the K2 was to be close to the holes
provided on both sides of the board for ground wires.  You can use any tip
from 1/8 inch up.  You tin tip well, and apply to bottom 0.25 in. of can in
spot size of the tip, while simultaneously applying solder.  As soon as the
solder wets the can and flows freely, remove the tip.   (2 seconds? or
less).   Then, you tin the solid wire lead.  I just use cut offs from
components.   Holding the scrap wire in plier or seizer tips, (narrow tips
to not suck heat away) apply the other, tinned end of the wire to the side
of the can in vertical manner, and apply soldering iron tip, (again wiped
clean first), and if needed apply some more solder to facilitate the wetting
and wicking action of the solder on the tinned lead and on the can side, so
that it joins.  Quickly again remove the iron.  Make sure there is a smooth
filet between lead and can solder.

As to harming the xtal, if you used a soldering gun, too big an iron/tip, or
carelessly laid the iron on for excessive time, you might harm the insides.
But, consider the sealed can xtals are welded or brazed shut, (high temp)
they have quartz element, (high temp) and maybe the only vulnerable point is
where the leads attach to crystal blank.  There it is plated, and the lead
"might" be soldered onto the plating, but I believe they may be sonically
welded.  The danger, if there is one, would be raising any interior gas
filling to an overpressure rupture point.  Even there, likely the can is
evacuated, (vacuum filled) or filled with inert gas like helium, if any.
In most xtal filters you lay out the board to have the wide sides of the
cans touching, or nearly, and thus the edge solder point for ground lead was
suited for that layout as well as how the board was predrilled.  That should
cover the subject---
Stuart
K5KVH