Voltage drop resistor for 5 20LF6 on 120VAC

[Hawke77]

Of course you would want to use a non polarized electrolytic, otherwise you could expect a furious pop and a nasty smell. I would suggest one that is designed to be used as a start/run capacitor for an electric motor. They are non-polarized and designed for higher current and longer duty cycles.

Hawke

 

[357]

The result is in farads. For the 33.33 ohm impedance it would be approximately 80 uF.

So I need this?

New!! 80UF 80 UF RUN OIL CAPACITORS CAPACITOR 370V - eBay (item 380186908247 end time Dec-20-09 08:03:14 PST)

that's huge

thanks for all the replies!

It is the eagle 515
I have put in 26lx6 for drivers, all new caps and diodes in the entire amp.
It's running great but I really dont feel good blasting the 20lf6's
The voltage sag is not enough, I have 123v and it may go down a few V but it's still overkill.
I put in a softstart and tried to to tone it down with thermistors but they didn't help much.
The worst was when it is in stock shape, when you turn it on it BLASTS the tubes and the drivers get around 30V, not too good for 20lf6's.

I had 30kd6 for drivers but they were gassy so I got some 26lx6 that seem to work perfect.
They look dimmer than the 30kd6's did so I have a happy medium.

I'd like the final 20lf6's which are original eagle tubes to get a proper voltage or they won't last long.
24V is alot for them, 19.5 would be great.

I am limited on room in the amp and would be able to get away with a resistor but transformers or that huge cap are my last resort.

33Ohms and 12W is respectable, probly go 20w to be safe.

What about two 16.66 Ohm power resistors at 10 Watts gold anodized aluminum case?
One on each side of the ac input?

 

[ken white]

So I need this?

New!! 80UF 80 UF RUN OIL CAPACITORS CAPACITOR 370V - eBay (item 380186908247 end time Dec-20-09 08:03:14 PST)

that's huge...

...33Ohms and 12W is respectable, probly go 20w to be safe.

What about two 16.66 Ohm power resistors at 10 Watts gold anodized aluminum case?
One on each side of the ac input?

That cap is rated at 370V, which is why it is so big. There are other smaller solutions that are not oil filled.

Your resistor solution will work too. I would go with the next standard value larger than the calculated ideal value. This will give you a slightly larger voltage drop which should help with tube life.

Have fun.

 

[357]

OK I got 2- 16.66ohm 10W resistors comming.

Here's my plan, will that work?

 

[Suicide Ride]

I woulda just run 5ea NOS 27LF6's & been done w/ it...... but that's me.

SR

 

[357]

Will a 600W 120V light dimmer work?

 

[357]

YouTube - Kenrich Eagle 515 resitor mod for 5 final tubes 20lf6

 

[tj305]

So I need this?

New!! 80UF 80 UF RUN OIL CAPACITORS CAPACITOR 370V - eBay (item 380186908247 end time Dec-20-09 08:03:14 PST)

that's huge

thanks for all the replies!

It is the eagle 515
I have put in 26lx6 for drivers, all new caps and diodes in the entire amp.
It's running great but I really dont feel good blasting the 20lf6's
The voltage sag is not enough, I have 123v and it may go down a few V but it's still overkill.
I put in a softstart and tried to to tone it down with thermistors but they didn't help much.
The worst was when it is in stock shape, when you turn it on it BLASTS the tubes and the drivers get around 30V, not too good for 20lf6's.

I had 30kd6 for drivers but they were gassy so I got some 26lx6 that seem to work perfect.
They look dimmer than the 30kd6's did so I have a happy medium.

I'd like the final 20lf6's which are original eagle tubes to get a proper voltage or they won't last long.
24V is alot for them, 19.5 would be great.

I am limited on room in the amp and would be able to get away with a resistor but transformers or that huge cap are my last resort.

33Ohms and 12W is respectable, probly go 20w to be safe.

What about two 16.66 Ohm power resistors at 10 Watts gold anodized aluminum case?
One on each side of the ac input?

hi 357 i have a eagle 500 on low it does 200 on hi 500 if i put 27lf6 in do i still have to do 33ohm 50 watts resistors .........tj305 73's

 

[W5LZ]

... add a sixth tube?

 

[tj305]

eagle 500 amp

it has 7 tubes 2 drive 5 all 20lf6 if put 27lf6 do i still have to bring down the voltage