Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

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

Philco 90 1st IF xfrmr question
#1

Discovered that the 1st IF transformer in the Philco 90 early model I am restoring is open on the primary side. Does anyone know if there are any suitable replacements on other Philco models? The secondary reads ~65 ohms, I assume that the primary was the same, as the xfrmr links two 24 tubes.
#2

(03-10-2012, 01:01 AM)TA Forbes Wrote:  Discovered that the 1st IF transformer in the Philco 90 early model I am restoring is open on the primary side. Does anyone know if there are any suitable replacements on other Philco models? The secondary reads ~65 ohms, I assume that the primary was the same, as the xfrmr links two 24 tubes.

I would think that as long as the fq is the same and the mdl 90 doesn't have any extra windings you should be ok. I know that some of the early Philcos use 175kc or 260kc. 262kc was popular among the tube type car radios. As for Philco perhaps a model 70 or 91.
Terry
#3

The early (2-45) and "mid" (1-47) versions of the 90 used a 175 kc IF. The late 90 with push-pull 47 tubes used a 260 kc IF.

A 1st IF transformer from a 111 or 112 should work also, since they also use a 175 kc IF. The part numbers are different but they appear to have the same type of mounting. Worth a try if you have a junk 111 or 112.

I used to have a couple 111/112 junk chassis around here, but I got rid of them a year or so ago. And I don't have a spare dual volume control, either; if I did, I'd send them your way...

--
Ron Ramirez
Ferdinand IN
#4

I tried one from a PP47 112 chassis that measured almost the same resistance- ~65 ohms both primary and secondary. It worked! But the set needs an alignment as the reception is not consistant across the dial.
This set had some wild "interpretive fixing" done on it at some point in time. I had to trace most of the wiring and in several cases re wire these fixes. Additionally, several resistors were drastically out of tolerance. The 1M ohm was reading 2 meg, and all 3 .25 meg were reading .35meg, .45meg, and .6 meg!!

The local distance switch was disconnected, and the leads of it and both 6mFd mershons were loosely twisted together.

It appears that all except one trimmer were screwed down tight. The one that was not was almost all the way out. Soooo, I adjusted them all to more or less center and did minor adjustments using strong local stations for a temporary fix once I got the set to play.

I installed the PP output xfrmr from the console speaker on the cathedral speaker I have, which was formerly for a single 47 output.
#5

Excellent! Good that you had a spare 112 chassis. I looked in the garage yesterday, and sure enough, I don't have my 111/112 parts chassis anymore.

--
Ron Ramirez
Ferdinand IN




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 91 Restore Code ??
I wondered about that. Wish there was some place local to get this stuff.dconant — 04:20 PM
Philco 89 indicator light.
Bending the lamp bracket (moving the lamp, that is) can possibly change the shape of the pointer a bit, but not its loca...morzh — 04:01 PM
Philco 91 Restore Code ??
Because the usable power rating of it hen is (3,200/20,000)*25W= 4W. Maybe a tad more due to the mass, but not much. Yo...morzh — 03:59 PM
Philco 89 indicator light.
Thank you Dan, that was the trick. I kept trying to rebend the lamp bracket but that wasn't doing anything to help.Jim Dutridge — 02:18 PM
Philco 91 Restore Code ??
20K 25 watt. I thought it was a 20 watt at first.dconant — 01:37 PM
My Philco 37-116 Restore
Nah, too much and not that important.morzh — 01:33 PM
Philco 91 Restore Code ??
What's the full value of that resistor?morzh — 01:31 PM
Philco 91 Restore Code ??
Been running the radio for three hours now. The power transformer has settled out at 140 degrees. The filter choke is ab...dconant — 12:38 PM
My Philco 37-116 Restore
Parts-express.com has them for around 5 bucks and up. You can probably get them on Amazon too.RodB — 11:48 AM
An attempt to remove the Field Coil from a G speaker
Last time I needed one of those, I ended up making one using a milk jug, scissors and a exacto knife.Ed Locker — 11:23 AM

[-]
Who's Online
There are currently 2296 online users. [Complete List]
» 1 Member(s) | 2295 Guest(s)
Avatar

>