40-180 Philco Power Transformer replacement part or substitution
Hello List,
I am restoring a Philco 40-180 radio and need a replacement power transformer. If you have a resource for cross referenced parts, forwarding it would be much appreciated. Part number for original transformer is 32-8052N (c. 1939). It seems that Models 40-180, 40-185, 40-190 could offer interchangeable transformers. If you have any information, I would greatly appreciate your assistance.
Thanks,
Larry
Posts: 139
Threads: 8
Joined: Aug 2013
City: Central PA
Hi Larry,
Welcome to the Philco Phorum! There are lots of great people here to help and provide insights.
The 40-180 is a pretty common radio, I am working on one right now. I dont have any additional cross reference for you, but these transformers should be easy to come by. Be sure to keep an eye on ebay.
Eric
Posts: 348
Threads: 48
Joined: Oct 2013
City: Tioga, Texas, USA
If you can find an original equipment type that is by far the easiest way to go. Of course if you have no way to verify it is good, it could turn into a can of worms. Make sure any such item has been checked at least by ohm meter to make sure the primary and secondary windings are good and have no shorts to the transformer case.
I did some checking against the schematic for your radio and I see these parameters about the power the transformer has to supply:
The B+ at the first electrolytic (item 61 ) is 270VDC and at the second electrolytic (item 58 ) is 185VDC. The field coil of the speaker serves as a choke and its resistance is 1100 ohms. There is an 85VDC drop across the field coil which means that the entire B+ load of the radio is drawing about 77.2 milliamps so round that up to 80 milliamps and that is the approximate power being delivered by the B+ circuits. The total amps of the filaments is about 2.35 amps if you allow for a couple of dial lamps of no. 44 type. Your radio may only have one dial lamp and it depends on what kind you install there. No. 1847 lamps draw only 150milliamps of current.
The rectifier is a no. 84/6Z4 type which has a separate filament winding requirement of 500milliamps at 6.3VAC. It would not be easy to find a readily available new manufactured transformer that would fill all of the requirements of voltages and current and still fit the chassis footprint of the radio. A replacement transformer would have to have two 6.3VAC filament windings, one capable of up to say 2.5 amps and one capable of the 1/2 amps the rectifier needs. The secondary windings of the transformer would likely have to provide about 390VAC across the end points and about 195VAC measured from the center tap to either end lead of that high voltage winding.
You may not find it easy to locate a type 84 rectifier. It has lower ratings for voltage and current capacity than the type 80 that is seen in many other Philco radios.
You might get lucky and find just a chassis available for spare parts with an intact power transformer. However, make sure it is checked before you spend your money. Also, make sure you have or can get a type 84/6Z4 rectifier tube before you go to far with any of this.
(This post was last modified: 01-03-2014, 12:57 PM by Joeztech.)
Posts: 214
Threads: 16
Joined: May 2010
City: Kokomo, IN
an 84 has a separate cathode so it can use same filament winding as the rest of the tubes and was wired that way the 40-180.
Posts: 13,776
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Joined: Sep 2005
City: Ferdinand
State, Province, Country: Indiana
Other radios that have usable power transformers for your radio:
40-150, 40-155.
41-250, 41-255, 41-280, 41-285, 41-287, 41-290, 41-296.
42-355, 42-380, 42-390.
I think Philco made seventy bazillion 41-280 sets (okay, 81,561), and there are plenty of parts chassis for these floating around. Not hard to find at all.
--
Ron Ramirez
Ferdinand IN
Posts: 348
Threads: 48
Joined: Oct 2013
City: Tioga, Texas, USA
Vinzer;
You are correct that it was originally wired that way and has an insulated cathode, but for best protection, B+ rectifier tubes should be on a separate filament winding, especially where there is no fuse on the AC input. If there is a fuse then I might trust it. I have seen such tubes short cathode to filament and if that happens and there is no fuse, the transformer goes.
Posts: 1
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Joined: Nov 2023
City: Vienna
State, Province, Country: Va
What size fuse did you use on the ac input?
Thanks
Posts: 1,906
Threads: 143
Joined: Jan 2013
City: Westland, MI
Hello Bwired9. This thread is over ten years old, so it may not be viewed by others as much. The 40-180 label lists the voltage at 115 and watts at 60. Using the equation A=W/V, the current draw is just slightly over 0.5 amps. Allowing for heavier draw on the circuits as the tubes heat up, I would use a 1.0 amp fuse. Take care and BE HEALTHY! Gary
"Don't pity the dead, pity the living, above all, those living without love."
Professor Albus Dumbledore
Gary - Westland Michigan
Posts: 1,472
Threads: 89
Joined: May 2008
City: Omak
State, Province, Country: WA
Hello bwire,
yes, I agree with Gary .
Sincerely Richard
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