[Hallicrafters] SX-111 Crystal in a Tube

[Glen Zook]

Actually, all HC6/U and similar type (longer like in
the 100 KHz ones) crystals are vacuum sealed.  If you
look near the top of the package you will see a
"solder drop" where the vacuum has been "pulled" and
then sealed off.

Now, the vacuum is not necessary for the crystal to
operate properly.  Basically, a vacuum was pulled and
in many cases an "inert" gas was then put into the
crystal package before sealing.

Collins used a metal type crystal with a tube base in
the crystal calibrator for the 75A2 / 75A3 receivers. 
I have had them go bad and have removed the metal
cover and replaced the insides with a "normal" type of
100 KHz crytals, replaced the cover, and no one knows
the difference!

Glen, K9STH


--- Bill Gerhold <wpgerhold at eLONGO.com> wrote:

Others stated the element is in a vacuum.  Does it
require a vacuum to operate?  I don't believe standard
or todays crystal packages are vacuum sealed.

=====
Glen, K9STH

Web sites

http://home.attbi.com/~k9sth
http://home.attbi.com/~zcomco

__________________________________________________
Do you Yahoo!?
Yahoo! Tax Center - File online, calculators, forms, and more
http://tax.yahoo.com