New Project with Wrong Power Transformer. WTD?

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Sorry to disappoint you but I don't have any beliefs. I'm just asking for info without getting an attitude in return.

Neither am I conveniently ignoring anything. There's much I don't understand here.

Others seem to be willing to help without judgement.

Proving me wrong on this forum is like bragging that you can beat up a two year old. Nothing is proved.

If you want to help, thanks. Otherwise, please don't post.
Get off your high horse and do some real listening.
It is clear you don't know much about the dangers of mains electricity and what can happen if your mains transformer is incorrectly wired up or incorrectly modified. And worst of all that some ningcompoop tries to rewind the primary without any knowledge. Your first post puts you into this last category.
Maybe I should have have been honest enough to have said that in my first post. My mistake.
 
Re-read post 4 - It answers your questions about winding space.
Also consider, the primary winding may well be in the centre of the transformer.
Meaning you would need to completely uncoil EVERY winding and start again with a bare bobbin.
Can someone answer me a hypothetical question -
can you use 2 - 110v primaries of a transformer to create an auto-transformer for this purpose (leaving the LV secondaries unconnected)?
Would you need to select the VA rating of the auto-transformer to match the VA rating of the main transformer?

yes of course, with one condition, that the traffo is big enough...
 
Hi Guys!
thanks up front!

On sale near me is a 110V VoM tape player that would make the perfect guitar amp:

1. all the right tubes 12AX7's, one 6V6

2. all the right secondary voltages 330, 5, 6.3, and it's center tapped.

So the problem is....... I live in a 240V area.

I saw on one site that if I wanted to rewind the primary to keep the secondary exactly as is, I would need twice as many windings. I'm going to assume that there's no room in there for 2X windings (Correct?).

I've also seen on this site warnings about not to run 240V through a primary designed for 120V, so I imagine that 240V requires thicker wires, making the space for twice the windings even worse. (Correct?)

So, short of buying a new power transformer or using a standard 240>120VAC transformer to place before the amp, what do you suggest I do?

the answer is on post #2 and as you hinted...just do it...
 
Are my assumptions about the windings correct?

I see that basically no one answered the actual original question you asked so I hope this is helpful.

No, the 240V windings would be wound with a somewhat smaller gauge since the mains voltage is doubled and therefore for a given power the current is halved. Barring core losses at the lower frequency power consumed in the transformer would be similar.

That said in Israel the economics of rewinding the transformer for 240V operation are not very attractive. (With care you can do it, I have, but it's not fun or easy.)

You do have several other choices; you could use a 240:120V autotransformer as suggested; you could have a local winder make you a new transformer with the correct specifications; you could purchase a new Hammond with dual primaries.

My family lived in Tel Aviv in the late 1960s and used an autotransformer to run our entire American stereo system, did have to modify the turntable pulley for 50Hz, but it worked. 😀

Shalom
 
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