Allwave 23 power transformer

[Thomas Day]

My recently purchased allwave 23 seems to have a partially shorted winding, probably the primary. Unloaded the transformer pulls between 3 and 4 amps. Output voltages seem close.

Is there any hope of getting this rebuilt?

Thanks

Thom

[Leonid Soloviev]

I know some people do re-wind transformers. So it is quite doable, especially if parameters are known.

Second option would be finding a close replacement.

Leonid

[Norman S Braithwaite]

Thom:

This is the second inquiry regarding a failed AW-23 power transformer this week!  See discussion at http://www.antiqueradios.com/forums/viewtopic.php?t=163545

I may have an extra power transformer but will not know until another member receives and checks the transformer on a recently shipped power supply.  If available, it will be less costly than having one rewound.  In any event, save the old one even if a replacement is found.  There will be a day when someone will need it for rewinding.

Norman

[Thomas Day]

Norman:

Thanks.

I am in Chicago and can probably find some one to rebuild the transformer. 

If you have one available, let me know. 

Thanks

Thom

[Thomas Day]

Hi.

Just want to say thanks for the lead on Heyboer. They will have the original transformer this week and will build a replacement. It turns out that they built most of the transformers for my first employer, Heathkit. Will let the list know how it all turns out.

Thom

[Scott Seickel]

Wow, they will make a new transformer to the same specs.  Mind sharing what a custom transformer like that costs?  I would think a lot.

[Thomas Day]

Don't have the actual cost yet, but when I talked with Alden, I said around $150.00 and he seemed to think that would be close. Their new transformers of similar capacity list for around $100.00. With the cost of copper, all new core laminations and the labor involved, plus a one off copy, I think that is very reasonable. The old one weighs about 15 pounds. That is a lot of copper and steel. The end result will be a new transformer with all new windings, better insulation material and drop in fit. It should be good for another 75 years. 

Thom

[Scott Seickel]

That sounds like a real bargain for a transformer that should be better than the original by a good margin. I figured labor involved with a custom transformer would be the real killer. 

Keep us posted. 

[Mal Fuller]

I'm glad that this seems to be working out.  Incidentally, Heyboer is also skilled in audio transformers.  Their role as an OEM supplier to Heathkit is interesting too.

[Marco M Midon]

Hello Tom, I have an allwave 23 power supply with the larger transformer designed for 20hz.  The 2.5 philimant winding developed a partial short about 50 ohms to ground.  I solved the problem by simply substituting a 2.5 volt transformer for the philimants.  The rest of the transformer windings are working fine.  I removed the block of 0.25 MFD capasitors and put this little transformer in there place.    

[Thomas Day]

Hi Marco:

In this case there is an internal short in one of the windings. Altho the output voltages seemed close, the primary pulls about 4 amps and you can smell it getting hot after a few seconds. Some one had replaced the power cord and the filter caps and the 2uf and .2 uf bypass caps. There was an extra 2A3 where the 83V should be. Sadly it has an open filament.

A new transformer is being built. The cost, tho not cheap, is very reasonable for a one off copy. 

[Leonid Soloviev]

By the way, there is AW 23 power supply on e-bay right now. Starts from $1.

Leonid