Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: upnorth2 on August 07, 2017, 03:25:31 pm

Title: BF Vibro Champ Power Transformer
Post by: upnorth2 on August 07, 2017, 03:25:31 pm

I've got a '65 Vibro Champ that has a unique PT. It's a factory original from what I can tell. The numbers were x'ed out and re-stamped. My question is this. It has an extra green/white wire that's taped off. I've seen this on other VC amp images on the web, just wondering if anyone else has encountered this and could it be a CT for the heater? I realize that Fender wired it the standard way anyway and if it were a CT I would need to lift the grounds from the tube sockets, run the extra heater wire, etc. Thanks for any insight. 


 (http://i.imgur.com/L0Z96W0.jpg)


 (http://i.imgur.com/JrYea03.jpg)

Title: Re: BF Vibro Champ Power Transformer
Post by: sluckey on August 07, 2017, 03:57:24 pm

Quote

My question is this. It has an extra green/white wire that's taped off... and could it be a CT for the heater?

It could be a center-tap. Use your ohm meter to see if it has continuity to both of your green wires. If so, then turn the power on and measure the AC volts between the green/white wire and each of the green wires. If it is a center-tap you should measure approx. 3.15VAC between the green/white and each of the green wires.