Egnater Reble 30

[Jay D]

Hello Forum:
Has anybody troubleshot an Egnater Reble 30 amp with the variable wattage control?


Thanks,

Jay D

[drewl]

Had one in a couple weeks ago.
What's the problem?

[Jay D]

Hello Drewl:
The problems I am having with the Egnater Reble 30 amp is the Reble 30 watts control.
The amp had vacuum tube 6V6 screen grid shorting , and took out the HV fuse F1, 315 mA Fast Blow.
Now after the change of tubes and fuse, the 30 wattage control has no effect on lowering the output power of the amp.
Traced the circuit, and replaced series pass mosfet transistor, TR1, and control transistor, Q1. Checked components in the series pass regulator circuit, and check o.k.
Went back to the Reble 30 watt control, and the pots are receiving 12 VDC from transistor, Q1 (MJE3055) wired on amp chassis.
Cannot get more than .8 VDC to the input R7 (47K resistor), and no matter which pots are switched into the circuit by the relay I have no control over the output power, derived by adjusting the +B voltage.
Is there any other components to check. I have a schematic with NO parts values, and filling them in as we go.

Thank You,

Jay D.

[drewl]

Can you send me the schem?
FWIW the one I had, the wattage control didn't seem to have much of an effect either.
The customer didn't say anything about it so I didn't bother checking it out.

[soundguruman]

Hello Forum:
Has anybody troubleshot an Egnater Reble 30 amp with the variable wattage control?


Thanks,

Jay D

If you call Bruce Egnator he might be able to tell you in just one minute what's wrong.

[g1]

You had a screen grid short, have you checked the screen resistor and screen voltage levels? Maybe they are doing something with the screen voltage to reduce the power?