Bush DAC90A O/P Transformer replacements

[Old Sparky]

Can an o/p transformer from either a BUSH VHF41, EKCOU319 or U354 be used to replace the Tx in a DAC90A? I realise that the '90A uses a UL41 o/p valve, whereas the others use UL84s, but, as the two valves are electronically similar, will a transformer made for the '84' work well with a '41'?

[tiv48]

I have used unknown output transformers to replace valve radio output transformers including in a dac90a and I know I used one for an el84 in a set with a ul41 .
it may not be the best thing to do but I have (so far) had no problems.
PS I now mark transformers from scrap sets with the model of the set and the type of output valve.
Rob T

[Radio Fixer]

In my opinion its not that critical. Providing you use a Xformer, of similar size, from a pentode set in a pentode set up (and triode for triode) and the speaker is the same Z it will work with no problems. For a more upmarket set then it may make a difference to quality and for Philips sets you may have feedback and hum reducing windings to think about.

Gary

[ed731pdh]

Any decent transformer of the correct ratio and resistance will do but be prepared to experiment with a few odd extra resistors in series with the primary winding to match it up.

[Steve_P]

Simple answer, Yes. Why are there universal ones if not?

A set like the DAC90A is a 'bog standard' design so any transformer from any other bog standard design will do just as well. Mains ones that is!

If you want to be sure, then pick one from a set with the same output valve or a similar one and you should be OK.

A lot of this sort of thing was done. While we're about it, some Output Transformers feed a signal back for a tone control. When this happens, get another O/P transformer to do the majority of the work, put it nearby and keep the original in place for the feedback.

With the back on, who will know. Another cowboy tip from Bodgitt and Scaper.

Cheers,

Steve P.

[Aerodyne]

UL84 anode impedance is 23k ohms, UL41 is 20k ohms, so you are close enough! Go ahead, provided that you can fit it physically - it might be slightly larger than the original.
Tony

[Nick]

You could always rewind the duff one - it's quite fun if a bit fiddly and only takes a couple of hours. ..

I wrote up the one I did at http://www.vintage-radio.net/forum/showt...hp?t=87213