[time-nuts] Glass Envelope Quartz Crystals

[Tim Shoppa]

Very interesting! Hazarding a guess.... higher end of a NT-cut? Looks much
like the third from the right here:
http://www.pbgquartz.com/www.pbgquartz.com/images/foto1.jpg

Some crystals in this range were used as filters or LO's in telecom
SSB-type channel banks (I think that's what the vendor who made that photo,
used to specialize in) but I don't know if those were generally NT cut or
what.

Tim N3QE

On Wed, Feb 3, 2016 at 8:21 AM, Philip Gladstone <
pjsg-timenuts at nospam.gladstonefamily.net> wrote:

> I dug around in my junk box, and found this:
>
>
> https://plus.google.com/+PhilipGladstone/posts/JBNLMSq2rsE?pid=6247050011623528018&oid=115465617973526125523
>
> This is (according to the markings) a 71.137 kHz crystal made in 1948. I
> suspect that they just measured the crystal after manufacture rather than
> actually trying to make a 71137Hz crystal....
>
> After this discussion, I'm feeling the need to fire it up and see whether
> it still runs, and what the aging has done to the frequency....
>
> Philip
>
>
> On 03/02/2016 07:11, Bob Camp wrote:
>
>> Hi
>>
>> There is actually a range of crystals shown in the pictures. The gold
>> plated 5 MHz
>> crystal is probably an overtone part. It could be fairly precise. The 25
>> MHz part is
>> plated with something like silver. It probably is a *much* lower
>> precision part. There
>> likely are long stories that explain just why this or that package got
>> used in this
>> or that application.
>>
>> Bob
>>
>> On Feb 2, 2016, at 10:04 PM, Jeremy Nichols <jn6wfo at gmail.com> wrote:
>>>
>>> The OP's picture looks very much like the crystals that HP's "Frequency
>>> and Time" division in Santa Clara (02 was their division number) used to
>>> manufacture back in the 1970s. My picture shows a 1 MHz crystal that HP
>>> used in the predecessor to the HP-105A (perhaps the 101A).
>>>
>>> Jeremy
>>>
>>>
>>> http://s323.photobucket.com/user/Jeremy5848/media/Miscellaneous/Crystal_1140587_zps0jxjpoal.jpg.html
>>>
>>>
>>>
>>> On 2/2/2016 12:24 PM, Don Latham wrote:
>>>
>>>> You have it right, iovane. At the least, they should be protected from
>>>> light,
>>>> thermal radiation, and emf.   Won'drous things will happen if the
>>>> crystal and
>>>> its structure are subjected to radiation through the glass. I'd suggest
>>>> a foam
>>>> wrap in a tin can as a minimum. Put the oscillator cat in there too.
>>>> Don
>>>>
>>>> iovane--- via time-nuts
>>>>
>>>>> 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.
>>>>>>>
>>>>>>
>>>>>
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