Metropoulos Forum

Heys guys need some help with 50 watt build...tubes in V1 and V2 won't light up. Tubes test good. Voltage on pins 1 and 6 of V1 reads really high. Voltage on pins 1, 6 and 7 of V2 read really high. I have no reading at all at pins 3 and 8 of V1 or V2.
Everything on V3 checks out ok and the tube fires up. HELP!!!

Thanks
Kevrockitt

What about you heater filament voltage on pins 5 and 9?

SteadyEddie wrote:What about you heater filament voltage on pins 5 and 9?

Yes, your heater wires have a dry joint or broken wire between V3 and V2

I will check all heater wire connections. I have 3.15 AC voltage readings at 4/5 and 9 on all three pre tubes though. I will keep posting results.

Thanks
Kevrockitt

kevrockitt wrote:I will check all heater wire connections. I have 3.15 AC voltage readings at 4/5 and 9 on all three pre tubes though. I will keep posting results.

Thanks
Kevrockitt

But you say your heaters do not light up, if you have ac volts the heaters should light up?

You will not get much voltage on pins 2 and 8 on V1 those are the cathodes

Pin 1 is the plate as is pin 6, so if V2 is reading high on the plates (1, 6 and 7) this suggests that your bus wire from the mid board filter cap or the second 10k dropper is open circuit.

Headin' to the bench to check that now.

OK...checked all bus wire....all good. So I replaced the heater wire run from V3 to V1.
Valves are firing! Everything is checking out fine now thanks to my fine friends on the Metro Forum.
Once again you guys come to the rescue!!!!
Thank you guys so very much!!!
Kevrockitt