Octal-based can, RCA # MI-9667.

Pinout:
6, 7 : winding #1
1,2,3,4,5: winding #2, multiple taps
8: electrostatic shield

Any idea what it's for? Thanks.

In article ,
(NewYorkDave) wrote:

Octal-based can, RCA # MI-9667.

Pinout:
6, 7 : winding #1
1,2,3,4,5: winding #2, multiple taps
8: electrostatic shield

Any idea what it's for? Thanks.


Input transformer?


Regards,

John Byrns


Surf my web pages at, http://users.rcn.com/jbyrns/

Since its an Octal can and probably quite small, its likely to be an input
transformer of some type. At a guess, microphone transformer with taps for
different mic impedances? The input side is what you refer to as winding 2.

If you can, put a low ac voltage from a signal generator on winding 1 and
measure the voltages on winding 2. You will have to play around a bit, but
you might find a common for all the secondaries. Find the ratio of the
voltages and this will give you the turns ratios (n). From this you can
calculate the impedance ratios (n squared) but don't forget that you are
driving it backwards.

Hope this helps, Mike


"NewYorkDave" wrote in message
m...
Octal-based can, RCA # MI-9667.

Pinout:
6, 7 : winding #1
1,2,3,4,5: winding #2, multiple taps
8: electrostatic shield

Any idea what it's for? Thanks.

NewYorkDave wrote:
Octal-based can, RCA # MI-9667.

Pinout:
6, 7 : winding #1
1,2,3,4,5: winding #2, multiple taps
8: electrostatic shield

Any idea what it's for? Thanks.

Put 1V at 60 Hz onto pins 6 and 7 and measure the voltages between the
pins on the second winding. You'll be able to figure out the ratios
this way, which is the first step toward figuring out what it is.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

In rec.audio.pro Scott Dorsey wrote:

Put 1V at 60 Hz onto pins 6 and 7 and measure the voltages between the
pins on the second winding. You'll be able to figure out the ratios
this way, which is the first step toward figuring out what it is.

The next step would be to put resistors in series with that
1 v source (1000 Hz is better than 60Hz but harder to find)
and when you find that value that divides the 1 volt, half on
the transformer and half across the resistor that value can
give a hint as to the function of the transformer. If the
input winding (6,7) is very high Z (100k or more) It's
likely a low Z mic to grid input transformer. If the Z is lower
than that then it may be some kind of line transformer.
It takes some serious measurements to work backwards to
the specs of a mystery transformer!

Benj

--
Due to SPAM innundation above address is turned off!

wrote:

It takes some serious measurements to work backwards to
the specs of a mystery transformer!


Awwww ! It's not that bad. ;-)

Had to do it often as a young hobbyist buying 'surplus' stuff on the cheap.


Cheers, Graham

In rec.audio.pro Pooh Bear wrote:
wrote:

It takes some serious measurements to work backwards to
the specs of a mystery transformer!


Awwww ! It's not that bad. ;-)

I didn't say it was impossible! ;-)

Had to do it often as a young hobbyist buying 'surplus' stuff on the cheap.

Me too! Of course like spy work it always helps if you
have some hints outside the transformer and measurements to
help you. Things like is it a power transformer? 60 Hz?
600 Hz? Audio? narrowband? wideband? etc. Even if you
know that the transformer is, something like determining
max levels or frequency response can take a decent test
setup. (Just did this with a mystery mic to grid transformer,
which it turned out was a really FINE unit!!! It is now
a very cool DI for my bass.)

Benj
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Due to SPAM innundation above address is turned off!