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Custom Hammond Power Transformer - Printable Version

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Custom Hammond Power Transformer - jrblasde - 12-20-2024

Has anyone ever gone the route of requesting a custom transformer design from Hammond? The transformer on my 46-480 looks to be in horrible condition. It’s heavily rusted, which has me worried about eddy currents in the laminated core. The holes for rivets are also all broken off, except for one. I’ve used their online request form to reach out with details of what I am needing.

Per the available Philco parts catalogs the Philco 32-8243 transformer is a 117V, 60Hz primary to 640V @ 85mA secondary. It’s got a 6.4V @ 3.45A rectifier output and a 6.4V @ 0.3A center tapped filament output. This is obviously very uncommon, and I can’t find a readily available replacement.

If anyone has gone this route, I’m curious about the turnaround time and pricing. I’m also entertaining a rewind, but I understand that this isn’t really any cheaper.

RE: Custom Hammond Power Transformer - Steve Davis - 12-20-2024

Just because it is ugly, doesn't mean it's bad. I would pull the rectifier and turn it on, check voltages and make sure it does not overheat. If it passes the test, clean it up and repaint it.

Steve

RE: Custom Hammond Power Transformer - morzh - 12-20-2024

For the transformer itself, I would (provided, I even consider dealing with a set like that) try to clean the surfaces and the bells (remove, de-rust, paint).
The rust on top of the core does not necessarily mean it is all the way inside.
By removing the bells, you will be able to see the conditions inside and judge as to whether the moisture/rust has penetrated deeper.
You could, after that, test the transformer and see if it functions, or it does not.


As for Hammond....considering the prices of their off-the-shelf products, I suspect their custom products of larger sizes will be not cheap at all.

I used to order custom from Heyboer; they had very reasonable prices, but they since stopped with custom ones.

RE: Custom Hammond Power Transformer - jrblasde - 12-20-2024

—Edited because I now see that the quote is confidential.—

Fair enough. You’re right, it’s worth the try!

No sooner than I sent this message, I received a response from Hammond. Definitely a prohibitive price for this restoration, but it was a fair price given the investment involved in a custom design. The lead time would be six weeks, which isn’t too bad either.

RE: Custom Hammond Power Transformer - morzh - 12-20-2024

The saying in Russian is, "the hide ain't worth the dressing", roughly the same as "the game is not worth the candles".
Unless this is a very, very valuable radio, or a family heirloom (guess not, judging by the condition of it), or any such special item, it is certainly worth of trying to do things by oneself, but paying about $400 for the transformer for this radio, that during a good market day would not sell for $50 even in better shape, to me is unreasonable.
Of course, it is not my money, so if you are willing to pay it, sure.

RE: Custom Hammond Power Transformer - jrblasde - 12-20-2024

I think I’ll go the route of cleaning up and testing the existing unit. Worst case scenario, I can explore rewinding. Surely that’d be a bit cheaper.

Haha, I studied a bit of Russian in high school and college. Доброе утро, друзья!

RE: Custom Hammond Power Transformer - GarySP - 12-20-2024

If you do need a transformer when all is said a done you could try Mark Oppat.
https://www.oldradioparts.net/item.html
Take care and BE HEALTHY! Gary

RE: Custom Hammond Power Transformer - jrblasde - 12-20-2024

Thank you, Gary! I’ll keep Mark in mind. Hadn’t heard of his website before.

RE: Custom Hammond Power Transformer - morzh - 12-20-2024

And good morning to you too Icon_lol

The actual saying is "овчинка выделки не стоит" (lambskin is not worth the dressing effort).

I did not know Mark rewound transformers.

RE: Custom Hammond Power Transformer - TV MAN - 12-20-2024

Don't condemn that transformer just because it's not pretty. May be fine. You can ohm it with a meter and get an idea. You can, as mentioned, pull the rectifier tube and check voltages. I'd recommend clipping out the line cap 1st to avoid any fireworks Icon_lol If it IS bad, find a used one, sub or parts radio.

RE: Custom Hammond Power Transformer - morzh - 12-20-2024

I would recommend removal of it before testing, as it would have to be cleaned anyway. Clean it, then test it outside the circuitry. With proper respect to the secondary high voltage.

RE: Custom Hammond Power Transformer - Arran - 12-20-2024

Most people that have needed a special transformer had Heyboer rewind it, though I am sure they are not the only outfit that does this. Edcor might be an option for getting a custom transformer made, they seem to special in it, and are not a Boutique priced as Hammond seems to be these days. However unless there is definitely something wrong with the original power transformer a dirty, rusty exterior doesn't really tell you that it's a dud.
Regards
Arran

RE: Custom Hammond Power Transformer - jrblasde - 12-20-2024

This is very reassuring. Thank you all for the feedback. I will isolate it and test it this evening. If resistance looks good across the windings, I’ll power it up and let it run for a bit to see if it heats up.

RE: Custom Hammond Power Transformer - morzh - 12-20-2024

Start with a Variac if you have it.

RE: Custom Hammond Power Transformer - TV MAN - 12-20-2024

You can also use a dim bulb tester. It wont isolate, but it will act as a fuse if something is shorted. Plenty of info out there about how to make one. You just stick a light bulb, like a 40 or 60W in series with your cord to your transformer. Cheap and effective. You probably have the stuff in your garage to make it.