Who made this little amp?

[Birddog2009]

Got it free from a friend. has no high voltage. Need a schematic..

 

[RadioGuy772]

Looks like either a single 8417 "jobby" but from the pic it maybe looks like the anode (plate) of the tube has a cap on it. What kind of tube does it have in it, and how do you know it has no B+ (HV)? What does it do, not do, etc? Have you just checked the circuit without firing it up first to make sure everything reads the way it is supposed to. This is probably a very simple amplifier, so by tracing things out you should be able to find the problem fairly quickly.

 

[Birddog2009]

Because the tubes don't light up and i cant get any high voltage readings that's why. It uses two 6jg6 tubes.

 

[Birddog2009]

No low voltages to the tube filaments either.. Amp turns on and i have 120 volts but nothing else... Ill post pics as soon as i can..

 

[Atlasta]

Could be a Scout or one of it's derivatives.

 

[Birddog2009]

A mini scout? Who made them?

 

[RadioGuy772]

Gotcha. So you have 120 volts, as in the PRIMARY of the transformer, correct? But nothing out of the transformer secondaries? Are you sure you have 120VAC all the way to the primary? Also, check the caps. On older, cheap, garage amps like this (sweep tube amps) typically they would use cheap caps, and after 25-30 years they tend to dry out, add short, causing you to blow the rectifiers and heat up the transformer in the process when you do get it turned on.

 

[TonyV225]

I believe thats an old amplifier made by "Elkin"

 

[Birddog2009]

I just put in new caps as the old ones looked pretty funky.

 

[w9cll]

LOVE the big red light

 

[Birddog2009]

bad rectifier diodes... I wonder if Radio Shack has any that i can use??

 

[RadioGuy772]

Yep, they do. As long as you have the eletrolytic filter caps changed, then rectifiers would be a good idea, as long as they are actually bad of course. But you said you were getting no voltage to the filiment either, did you solve that?

 

[Birddog2009]

I replaced them and the amp is working 100%!
I had a Demco Demon 500 amp that had the very same issues with the diodes in the rectifier going bad and it blew fuses. I replaced them and it also worked 100%.

 

[Birddog2009]

Oh and the issue with the filaments B+ voltage was weird. It was the fuse that was bad that caused that however it did not blow when the 120 was applied to it only when the HV was applied then it blew.. So the amp turned on and had 120 volts that lit the status light but no HV... That's when i found out the diodes were at fault.. The bad diodes were causing the fuse to blow...