[Milsurplus] puzzler - module with glass rod?

[Ian Wilson]

My first job was working on SAW devices, in 1973. They were nowhere near
practical for use in equipment until the mid-to-late 70's at the earliest.
Bulk
delay lines were around much earlier.

SAW devices were very cool. You design the device by taking a Fourier
transform of the frequency domain response that you want, and then print
the result as metallization on the surface of a suitable piezoelectric
material (Lithium Niobate was a favourite). These days I don't think they
are used except for some very specialized filters with unusual group
delay specs.

73, ian K3IMW

On Mon, Apr 4, 2016 at 10:11 PM, <antqradio at sbcglobal.net> wrote:

> As far as I know, practical SAW devices date from the early 1960's.  The
> module looks to me to be from the late 1940's to perhaps the late 1950's.
> No obvious inter digital transducers are seen on the surface of the glass
> cylinder.  Then there is the issue of only one connection to the rest of
> the module so there is only an input to Z1 and no output.  So I don't see
> Z1 as either a SAW device or as a delay line.
>
> Since Z1's only port is connected to the flying coax lead and the closest
> vacuum tube is labeled V2, then that coax must be an output to some other
> module in the system.  There is a BNC female flange connector close to V1
> so this must be the module input.  V1 and V2 are 6AK5's but I can't see any
> markings on the top that identify the other four vacuum tubes so it is
> difficult to figure out the rest of the circuit.  T4 seems to be a coaxial
> transformer so the frequency is still very high up to this section of the
> circuit.  There seems to be a flying lead that goes through the partition
> near the input BNC input connector.  What is happening on the other side of
> the partition is anyone's guess.
> Jim
>
>
> ------------------------------
> *From:* KD7JYK DM09 <kd7jyk at earthlink.net>
> *To:* Ian Wilson <ianmwilson73 at gmail.com>
> *Cc:* Military Surplus Mail List <milsurplus at mailman.qth.net>
> *Sent:* Monday, April 4, 2016 10:03 PM
> *Subject:* Re: [Milsurplus] puzzler - module with glass rod?
>
> : Way too big to be a SAW device, methinks.
>
> Yes, BUT...  Look how it's designed, how it's labeled and work back,
> technology wise, a good chunk of a century...  Think of the first
> transistors compared to the ones we have now that are measured in size
> comparable to wavelengths of light.  Could be an old, inefficient and low
> frequency SAW filter.
>
> Kurt
>
> ______________________________________________________________
> Milsurplus mailing list
> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Milsurplus at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20160405/1998f76f/attachment.html>