[time-nuts] Glass Envelope Quartz Crystals

[iovane at inwind.it]

I think that these crystals were designed to be placed in an oven, which worked 
as a shield too. I have a similar crystal made by Racal in the 60's, and in my 
case it is fitted with the classic octal tube-type plug. It was housed (still 
is) in a heavy massive shimmering chrome-plated cylindrical brass enclosure, a 
beauty to see, It was the timebase of a tube-type synthesizer with lots of 
tubes. Themperature control was achieved by means of a mercury thermometer in 
which mercury actuated a contact when reaching a wire crossing the capillary 
tube.

Antonio I8IOV

>Da: Bob Camp <kb8tq at n1k.org>
>Data: 02/02/2016 13.15
>A: "Discussion of precise time and frequency measurement"<time-nuts at febo.com>
>Ogg: Re: [time-nuts] Glass Envelope Quartz Crystals
>
>Hi
>
>Since the 25 MHz crystal has already been soldered into a circuit, putting it 
in a 
>socket is probably not a real good idea. It’s also a leaded part. Even with 
fat pins
>sockets can be an issue. With wire leads, you are asking for trouble. 
>
>Functionally, there is little there is little difference between a glass 
package crystal 
>and a metal package. About the only real one is the obvious - one has a metal 
shield
>you can (but sometimes don’t)  ground. 
>
>Bob
>
>
>> On Feb 1, 2016, at 9:58 PM, Daniel Watson <watsondaniel3 at gmail.com> wrote:
>> 
>> Hi,
>> 
>> I purchased a pair of interesting glass envelope crystals for a project.
>> Here are some pictures:
>> 
>> http://syncchannel.blogspot.com/2016/02/glass-envelope-quartz-crystals.html
>> 
>> Does anyone have an idea about what mount/socket I should buy for these? I
>> read a previous thread on the list about Bliley crystals using a B7G mount,
>> but I'm not sure if that type might work here.
>> 
>> Also, when building up a circuit to make these oscillate, are there any
>> specific differences about crystals in this package that I should keep in
>> mind?
>> 
>> 
>> Thanks much,
>> 
>> Dan W.