Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco 112 speaker specifications?
#1

Do you know the field coil specifications for the speaker in the late model Model 112 with the '47 output tubes?  Somebody gutted the speaker in mine, and used one winding of some puny transformer in place of the field coil.  

Web site: http://www.masekconsulting.net
Radio Photos: http://www.photobucket.com - album id FStephenMasek
#2

If you haven't already, check Ron's spreadsheet of Philco speaker specs (speakers.zip) which can be found here:

http://philcoradio.com/phorum/showthread.php?tid=215
#3

Thanks! The clown who worked on it previously used a winding with just a few hundred ohms resistance, when the correct choke should be 3,200 ohms. That would have made B+ way too high.

Web site: http://www.masekconsulting.net
Radio Photos: http://www.photobucket.com - album id FStephenMasek
#4

 Clearly something went wrong with the speaker field coil in this set, which was why they attempted to make a choke or of a small transformer. Either it was damaged by a shorted filter cap or the winding just failed mechanically for some reason. In any event it's the inductance that matters not the DC resistance, the DC resistance of a proper iron cored choke can be lower then a type H Philco speaker and still work as long as it has the same number of Henries. It would be easier just tracking down a replacement H series speaker rather then rewinding the field coil, but if the original speaker is otherwise intact, and you can get the bobbin out of the frame to rewind it, why not give it a go just for the experience?
Regards
Arran
#5

The original speaker was gutted, as I wrote above. The end of the field coil enclosure and mounting bracket closest to the cone was drilled out to make room for the magnet of a PM speaker fastened into the old basket.

Yes, I should have written about the Henries, and I do have a meter to measure Henries, but do not know the specification of the original in Henries, just the DC ohms listed on the spreadsheet. There is no way the one winding of the small transformer the hack used would have the same rating in Henries as the large old field coil.

Web site: http://www.masekconsulting.net
Radio Photos: http://www.photobucket.com - album id FStephenMasek




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco Model 76 Highboy
Back in Feb I scored a nice model 95 Highboy, see earlier post.  Saved from a guy that likes chopping them up into Liquo...slford310 — 09:49 AM
Philco Model 71B
Adding a pic from the other side and the inside.  It will be a bit of work and a challenge but that's what makes it fun....slford310 — 09:32 AM
Philco 89B code 123 newbie
Hi Kurt Welcome to the Philco Phorum. Lots of phriendly pholks (see a pattern here?) who are happy to help.  Keep posti...MrFixr55 — 08:36 AM
Philco 89B code 123 newbie
Hello Kurt, Welcome aboard and you have a nice set to start on ! Yes, the bakelite blocks and I too find them fairly...radiorich — 07:12 AM
Philco 89B code 123 newbie
Getting started on my first Philco here, done some research and hopefully I now know enough to be dangerous.  :) Overal...Kurt P — 01:44 AM
Delco car radio Peko vibrator converstion issues
Richard, I reviewed the Panasonic specification sheets for this type capacitor and though dV/dt is discussed, there a...Chas — 11:48 AM
Philco Shipping Crate
I picked up a nice set of KLH 20 speakers ca 1980, for $40, and a Telefunken 5083W "Allegro" AM FM SW radio, a...MrFixr55 — 10:52 AM
Philco Model 71B
Absolutely looking at replacing the arch veneer and sides. Good luck stripping the front face ... hope the paint hasn't...GarySP — 10:31 AM
1953 Music Masters 620-9 Australian Radio Restore
That's a very interesting radio Buzz. Looking forward to more installments on this one!Eliot Ness — 10:31 AM
Philco Model 71B
OOPs, Dumb me. The title of the post is Model 71B. DUH!! Yes, the 71 uses an autodyne detector, but it is more like t...MrFixr55 — 10:21 AM

[-]
Who's Online
There are currently no members online.

>