Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

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
Stromberg Carlson 1500 Squeal
And life just keeps getting more complicated. By dconant. Dittos'Jimradio — 08:01 AM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
That looks a lot like an aircraft connector of some kind, even if it's a U.S.N power supply. I have a book somewhere abo...Arran — 02:56 AM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
hello david, I have a similar generator in my collection that features a cast iron, single-cylinder Briggs & Stratt...radiorich — 01:00 AM
under chassis parts locator diagram for 1938 Zenith 9s262
Has anyone gone to the trouble of creating an under chassis parts locator image?  Yes, I can identify components by foll...bobloney — 08:57 PM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
Try looking at this site the book mark is for a old generator that I was given. David    https://radionerds.com/index.ph...David — 08:36 PM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
Hello Everyone, I am looking for voltage identification for all the pin positions on the socket of a CRV-20130 power su...Tonym4704 — 08:16 PM
Philco P45-6365 Universal Transformer Instruction Manual
Can anyone guide me to where this may be found?GRG — 03:00 PM
54C Complete Teardown/Rebuild
I don't think that I have encountered a 12Z3 before, curious how it uses one of those but includes a #43, which is a 25 ...Arran — 02:17 PM
HiFi (Chifi) tube amp build - but my own design.
It's the other forum. I'm also in DIY, but mostly read there. Honestly, I kinda jumped into this without much thought to...TV MAN — 10:43 AM
Philco 71 Code 125
Hello,  I am in need of a schematic for this radio. Mine has the three separate circular tube shields and a shadow me...dconant — 08:06 AM

[-]
Who's Online
There are currently 1481 online users. [Complete List]
» 1 Member(s) | 1480 Guest(s)
Avatar

>