Urei 1178 Power Transformer Replacement

[industrialarts]

Hi

I have an 1178 that needs a new power transformer. Can't find an original (not suprised) but having a little trouble finding a sub. The only thing I found so far is this - https://www.hammfg.com/files/parts/pdf/266G36.pdf

Any other suggestions much appreciated

Thanks

 

[dmp]

You're on the right track -- it needs a 18VCT secondary.
Decide how close you want to stay original - with the EI type mounted to the side and if you want it to fit the same mounting holes? (measure them)
Or put in a toroid for (possibly) better performance (less induced magnetic hum) mounted to the side wall, like this

 

[industrialarts]

Thanks - yes, I did do a bit of my homework. The footprint of this one is a little larger (few mm) than original. However, the original has bell covers and wire leads but no biggie.

I found this toroid searching now but the AnTek link you gave seems pretty inexpensive for a toroid. I don't much about them, any other info you could provide? Definitely looks interesting, I have a handful of other projects that could use something like that.

Thanks

 

[Whoops]

I have an 1178 that needs a new power transformer.

What happened to the original transformer? is it burned?

If that's the case that can be easily re-winded,
let me know your location

Can't find an original (not suprised) but having a little trouble finding a sub.

Not need for an original there's many many power transformers that could be used to replace the original one.
It's a simple 2x18V transformer

I found this toroid searching now but the AnTek link you gave seems pretty inexpensive for a toroid.

That Toroid in the link will work very well for sure.
That's exactly what I would do, replace the original one with a toroid transformer, you will have less EMI with a Toroid.

Basically you only need a Toroid transformer (or an EI transformer) that has 2x 18V secondaries and is rated from 30VA to 36VA, you can use 50VA also but the extra wattage will not be needed and it will be slightly bigger.

Some other options:

https://www2.mouser.com/ProductDetail/Triad-Magnetics/VPT36-1390?qs=wkKrz7WmEgM2EIrgD3Tzhw==
https://pt.farnell.com/en-PT/vigort...former-2x18v/dp/2817646?st=toroid transformer
https://pt.farnell.com/en-PT/vigort...former-2x18v/dp/2817653?st=toroid transformer

 

[dmp]

I've used a lot of antek toroids and like them a lot.

 

[CJ]

i rewound a 1176 xfmr, do they have the same specs?

came out to 336 turns of #30 times 2 on an EI 75, so about 1250 turns of #36 on each primary

the original was poorly manufactured, just like the brown acid at woodstock,

 

[industrialarts]

Thanks for all the help, the AnTek stuff is new to me and looks swell. I have encountered very few toroid ouput xfrmrs - that looks cool as well.

The Vigortronix VTX-146-030-218 seems to be fine as well, a little higher VA rating - the 50VA of the other is overkill and might not fit. I'll return the original to the owner for 'vintage value' and it can be rewound at a later date if anyone feels the need.

Thanks again!

 

[dmp]

For future reference, antek has a ton of transformers in different Voltages and VA

https://www.antekinc.com/grids/

 

[industrialarts]

I ended up using this one - the toroids were not a good fit to the case and pc board placement. The case and footprint are almost the same as the original

Thanks again for all your assistance