The PHILCO Phorum
transformer 32-7993 in 39-116 console - 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: transformer 32-7993 in 39-116 console (/showthread.php?tid=20848)


transformer 32-7993 in 39-116 console - k6ddj - 01-10-2020

Hi all,
Need a little help understanding a circuit connection.  I am restoring a 39-116 console.  The separate filament transformer 32-7993 physically has 2 primary leads and 2 secondary leads.  The transformer is stamped as 32-7993 and is original.  The problem is that the schematic has this transformer as 3 (three) leads for the secondary.  The actual transformer has almost exactly 6 ohms between the two secondary leads that are there which is correct by the schematic but does not have the third lead as shown on the schematic, which is supposed to have less than 0.1 ohms and powers the 2A4 Filament.  What the heck is going on with this transformer and this wacky schematic?.  Examination of the leads inside the transformer's case shows no sign of there ever being a third lead in the secondary.

Thanks for any help
Dean

RE: transformer 32-7993 in 39-116 console - klondike98 - 01-10-2020

Here's a link to the schematic so folks can better help you out. Having said that, it looks like the center tap on the secondary is connected to one leg of the primary and that is likely a connection made internally in the transformer.

RE: transformer 32-7993 in 39-116 console - Bill Bacco - 01-10-2020

Looking at the schematic, it appears as if the center secondary connection is also connected to one of the primary wires. Maybe that is done internally. Either that or the schematic is wrong. Do you get any continuity between the primary and the secondary for the 2A4 filament?

RE: transformer 32-7993 in 39-116 console - k6ddj - 01-10-2020

Excellent call!  Yes the connection is internal and now fully understood what is going on.  I never considered the possibility of an internal connection.
Thanks so much for your insight and knowledge.

Dean