The synchro used by Telrex is a 400 Hz synchro run at lower than rated
voltage at 60 Hz. It also has an unusual small diameter threaded shaft.
I suspect you will not be able to find a direct replacement on the
usual hamfest or ebay market. If a new direct replacement is available,
its likely to be very expensive. Perhaps rewinding your existing
synchro or redesigning the control box to use more readily available
components are the most practical solutions
---- Original message ----
>Date: Sat, 27 Jan 2007 03:52:00 -0800
>From: Jim Lux <email@example.com>
>Subject: Re: [TowerTalk] Telrex rotor Selsyns
>To: Bee Walton <firstname.lastname@example.org>, email@example.com
>At 02:24 PM 1/26/2007, Bee Walton wrote:
>>Anyone know a source for the Selsyn transformers for the Telrex rotor and
>>control box? Fair Radio or SSof NE do not have them. Details and specs
>>can be provided if required.
>Selsyn is a trade name for a synchro. (GE, I think).. so googling
>for synchro might find more info.
>These things are fairly standardized, in terms of size (i.e. is it a
>size 23 or something else) and voltages and impedances. C&H Sales in
>Pasadena, CA, used to carry a fairly large selection of them
>(transmitters, receivers, funky transformers, etc.) but I have heard
>that C&H is going out of business (after many decades) so they might
>not have any left.
>And, of course, you can buy new ones (Check the Thomas Register to
>find mfrs.. I think Moog is one http://www.polysci.com/ ) or get the
>old one repaired. A company called Windings, Inc.
>New Ulm, MN 56073
>ph (800)795-8533 fax (507)354-5383
>Synchros are widely used as position encoders, and there's a raft of
>special purpose ICs or modules that take the three phase AC signal
>from the synchro and turn it into a digital word. Companies like DDC
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