Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

Heathkit W5m Power Transformer?
Heathkit W5m Power Transformer?
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 1st August 2019, 01:13 AM   #1
maniac303 is offline maniac303  Canada
diyAudio Member
Join Date: Sep 2015
Default Heathkit W5m Power Transformer?


I am rebuilding a pair of W5m and one has a short in the power transformer HV secondary. I have a few related questions;

1. Do any of you kind souls have a working power transformer for a W5m? (Heathkit part number 54-32) There are none on EBay at the moment.

2. The transformers have two numbers on them, both labelled 54-32, but one is labelled 138626 and the other 1386304 with STANCOR ELECTRONICS INC. on it as well. I know other manufacturers made TFs for this unit, but if I search these other two numbers the TFs that I find don't seem like a match. This may not be important but does anyone _know_ what these second numbers designate? Cheers.

3. The chassis are in pretty rough shape. I am considering stripping, blasting, repainting and relabeling. Does anyone know a good DIY source for hi-rez silk screens made from computer art? Feel free to lecture about resale value and all that, but I mean they are in _really_ bad shape, one is badly bent. I am rebuilding the non-functional amps with the intention to use them, not intending to sell.

  Reply With Quote
Old 1st August 2019, 06:47 AM   #2
indianajo is offline indianajo  United States
diyAudio Member
indianajo's Avatar
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
Getting a matching OEM transformer for a decades old product is like searching for the holy grail. You might find one in a similar unit, but then it might be easier to rebuild the dead unit you buy. Heathkit amps for parts or repair on e-bay tend to be pricey. If that is a vacuum tube amp that makes the purchase price even more improbable. This junk amp market may be moving to facebook, which will be invisible to me since I don't give out my birthdate to any publisher for free.
One can calculate the current demand at what voltages to determine what generic replacement transformer will work. Current use is in tube datasheet. Output transistor design currents tend to be in the SOA table @ what working voltage. The current limit in transistor tables is a rediculous number telling you only how big the bond wire is. If the transistors are house brand, go by what top end output transistor was popular in the year the amp was made.
Guitar amp shops are good sources of replacment transformers. In the US I can think of tubesandmore.com and triodelectronics.com I am sure you have as good suppliers in Canada without paying the stupid UPS/FedEx loan origination fee (~$20) for the customs fee. Hammond Industries is one brand that comes to mind. The stancor factory was redeveloped as a shopping mall or something. All the old US transformer brands are now built in the land of all manufacturing - and all counterfeiting, too.
I find the best bargains in amp hulks to be Peavey. They are reviled for some reason, I got a good PV-4c hulk for $20 with freight. $80 parts to reactivate. Two 65 VCT @ 4 A transformers, one for each channel. Crown & QSC for parts or repair are a little more pricey. Most other brands had figment of the imagination power ratings anyway.
Silk screen shops tend to be local, it is a low tech process much like photography. Ask around small run print shops. The same screen that works on T-shirts would work on a front panel.
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300

Last edited by indianajo; 1st August 2019 at 06:57 AM.
  Reply With Quote
Old 1st August 2019, 05:56 PM   #3
maniac303 is offline maniac303  Canada
diyAudio Member
Join Date: Sep 2015
Default Heathkit W5M Power Transformer?


The amps are circa 1951, Williamson based, running a 5R4GY, 2 x 12AU7 and 2 x KT66. I am planning to keep the iron (and nickel in the case of the Peerless 16309 OTs) and replace almost everything else. My affinity is for the elegance and simplicity of the amplifier circuit rather than the antique black beauty caps etc. The Heathkit build manual has a great description of the amp, and is a good read:


Given that the iron is about all I plan to keep I think I will try to be patient sourcing an original replacement. They do come up on eBay from time to time. At the same time they are known to fail, potentially a product of aging caps, higher line voltages and other issues. Heathkit actually advocated a mod, a 'surgistor', to address the issue, and I plan a number of minor changes in this regard as well. The failure rate of the PT may explain the high ratio of Chokes:PT on eBay. Several chokes available, no transformers.

The PT has somewhat unusual specs, 910V w/CT @ 140ma, 6.3 w/CT and 5. I have yet to find an exact, or even suitable match in the aftermarket, and I would prefer that both amps have matching power supplies. If all else fails I may be re-potting and repairing, a learning experience to be sure!

Thanks for your reply!
  Reply With Quote
Old 1st August 2019, 06:17 PM   #4
rayma is offline rayma  United States
diyAudio Member
Join Date: Apr 2011
Lot Of 10 Transformers From Vintage The Fisher & Magnavox Stereos | eBay
  Reply With Quote
Old 1st August 2019, 10:38 PM   #5
maniac303 is offline maniac303  Canada
diyAudio Member
Join Date: Sep 2015
Default Heathkit W5M Power Transformer?

Yes, this is an example of one of the few hits I get if I search for "1386304", but I have no idea if that is a vendor ID, manufacturing date code, or what it means exactly. The other number on that particular transformer on eBay, 300215-2 , has so far told me nothing.
  Reply With Quote
Old 3rd August 2019, 01:01 AM   #7
trobbins is online now trobbins  Australia
diyAudio Member
trobbins's Avatar
Join Date: Feb 2009
Location: Melbourne, Oz
You may find some snippets of information in the following 2 threads (as well as a lot of the opposite):
Heathkit W5M restorations and mods ideas | Audiokarma Home Audio Stereo Discussion Forums
Mystery Device found in Heathkit W4-AM | Audiokarma Home Audio Stereo Discussion Forums

Heathkit did use multiple transformer makers, but even some of those makers were just related divisions in a changing landscape of transformer manufacturing facilities over the decade or so of interest. The W5M started sales circa 1955, and appears to have still been part of Heatkit's adverts and warranty repairs in to the mid 1960's. There were lots and lots of these kits sold, and hence they are seen on ebay, and some have got them custom made as a repair, or looked around in detail for the closest commercial match. The many examples of them failing may just be equivalent to the many many units originally sold, but like any vintage gear I'd highly recommend adding some extra protection to alleviate the chance of the power transformer being collateral damage to something else failing, even it it takes away from the aesthetic 'original' condition.
  Reply With Quote


Heathkit W5m Power Transformer?Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
WTB Heathkit 54-13 Power Transformer (A9, W3M, W2M) deicide67 Swap Meet 0 12th April 2019 11:57 AM
WTB Heathkit aa1600 54-948 Power Transformer heathkit82 Swap Meet 2 18th April 2013 09:20 PM
WTB Heathkit power transformer Burnedfingers Swap Meet 6 23rd November 2007 12:58 PM
Wanted: Heathkit power transformer Boris_The_Blade Swap Meet 0 9th June 2007 07:13 AM
Need Help on HEATHKIT W-5M Power Transformer speedemon Tubes / Valves 2 20th March 2007 01:51 AM

New To Site? Need Help?

All times are GMT. The time now is 03:01 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio