Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: coldfire on September 23, 2019, 03:01:22 pm

Title: Mystery Xfmr
Post by: coldfire on September 23, 2019, 03:01:22 pm

Hi Guys
     
    Been reading the forums. Finally making my first post. Slight dilemma here. Rooting through a box of old transformers, I came across
this one. I want to say this was from an old Fender amp I had about 40 years ago but can't be sure.
I ohmed it out and got the following readings ( see attached). Has anybody seen one like this or know what it is. The only marking
on the transformer was stamped on. Unfortunately it has worn off. The only thing I can make out is "S-105". Any help would be greatly appreciated.

Thanks in advance

Title: Re: Mystery Xfmr
Post by: shooter on September 23, 2019, 03:16:27 pm

If you have an AC signal source ~~ 1Vacpp
read this thread, you can skip o reply #10 - 25, or read it all for fun  :icon_biggrin:

http://el34world.com/Forum/index.php?topic=25067.0

Title: Re: Mystery Xfmr
Post by: PRR on September 23, 2019, 08:08:45 pm

I am guessing 120/240VAC to 15-7-0-7-15VAC at around 20VA. A small transistor practice amp, not a tube amp.

Title: Re: Mystery Xfmr
Post by: coldfire on September 24, 2019, 05:40:30 pm

Hi Guys

     Thanks for the input. PRR, you were right on with the voltages. I measured it out
and got the following.

Unfortunately, can't use it for a tube amp.

Anyway, thanks again.