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Mystery RCA transformer
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. |
#2
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Mystery RCA transformer
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#3
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Mystery RCA transformer
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. |
#4
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Mystery RCA transformer
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." |
#5
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Mystery RCA transformer
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! |
#8
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Mystery RCA transformer
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 -- Due to SPAM innundation above address is turned off! |
#9
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Mystery RCA transformer
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 -- Due to SPAM innundation above address is turned off! |
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