Output Transformer Question... - Printable Version
+- The PHILCO Phorum (https://philcoradio.com/phorum)
+-- Forum: Philco Radio Discussions (https://philcoradio.com/phorum/forumdisplay.php?fid=5)
+--- Forum: Philco Electronic Restoration (https://philcoradio.com/phorum/forumdisplay.php?fid=8)
+--- Thread: Output Transformer Question... (/showthread.php?tid=20980)
+- The PHILCO Phorum (https://philcoradio.com/phorum)
+-- Forum: Philco Radio Discussions (https://philcoradio.com/phorum/forumdisplay.php?fid=5)
+--- Forum: Philco Electronic Restoration (https://philcoradio.com/phorum/forumdisplay.php?fid=8)
+--- Thread: Output Transformer Question... (/showthread.php?tid=20980)
Output Transformer Question... - mikethedruid - 02-14-2020
As you may have read, I have problems with my speaker for the 37-640 project I am working on. Just in case nobody has a K34 speaker they will sell me, and I have to repair what I have, I have ordered this output transformer from AES. https://www.tubesandmore.com/products/transformer-output-8-w They have a 10% off sale, so I figured I'd grab it while I could, such things are always useful eventually, even if I can't use it now. I read the reviews, and they said they work OK in such push-pull circuits. I am wondering if some of you might look at it, and give me your opinions on how it might work out as a replacement for the one in my 37-640. Any advice will be appreciated.
RE: Output Transformer Question... - radiodale - 02-14-2020
Just disconnect one lead going to the voice coil and measure the resistance. It will either be closer to 4 or 8 Ohms. Use that info to determine which terminals to use on the transformer.
RE: Output Transformer Question... - morzh - 02-14-2020
It is closer to 1 ohm in K34.
In early philcos it was from 0.3 ohm , 0.7 was popular. This one is 1.1, I think.
RE: Output Transformer Question... - mikethedruid - 02-14-2020
Yes, Mike, it is in the library here, 1.11 ohms.
RE: Output Transformer Question... - morzh - 02-15-2020
Magic number.