Philco 3537 interstage transformer - Printable Version

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+--- Thread: Philco 3537 interstage transformer (/showthread.php?tid=9364)

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Philco 3537 interstage transformer - morzh - 04-22-2014

I used my LCR meter to look at the 3537 transformer used in Philco 111. The Table on Chuck's website does not list inductances.

The primary inductance is about 25H, +/- 2H at 1000Hz.
The one half secondary is 93H to 100H, which makes the full one about 180 to 200H.
The leakage inductance is 165mH.

This makes the primary and leakage data closest to Hammond 124B.

Of course there is the discrepancy of 1:4 for Philco and 1:3 for Hammond's turns ratios.

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RE: Philco 3537 interstage transformer - vinzer - 04-23-2014

Outside of a rewind or custom wound transformer theres not much available I use a 124e in my sparton 1466 which the push pull driver to push pull output was all so 4-1 with a 124e which was 3-1 I have had this radio since the mid 1964 and the original failed about 2 years ago so I know what it sounded like before it failed could not tell any difference this radio has variable if bandwidth 20 watts output and 12" woofer two 5" tweeters. I think it should be fine to use a 124b in yours I put it in the old housing so it still looks original,

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RE: Philco 3537 interstage transformer - gregb - 04-23-2014

I just installed 124, sorry forgot the letter, driver for a guy in his Airline radio with a #27 driving PP 45's and it sounds great with tons of volume.

Gregb

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RE: Philco 3537 interstage transformer - morzh - 04-23-2014

I am considering buying an 124A or B (E is not necessary and in fact B is closer to the Philco one in primary inductance so the response would be the same more or less).
The difference between A and B is almost 20 bucks. I am somehow sure there will not be huge difference in quality - this is after all not a HiFi output.

But first I want to get replies with quotes from Heyboyer and MTT (the latter is in NJ close to me). Just wonder what they suggest money-wise, they would have to unwind and replicate.

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