4CX1000A in grounded grid ( 4CX1000 GG )

[w4bfs]

Hi Patrick ..... W5CBS runs a 4CX1000 at 3 kV with screen grounded and control grid tied to cathode (W6SAI super cathode) .... 100 W in makes 1500 out and stable ....give Gene a call fo mo info .....73 ....John

[W4AAB]

I have a 3CX1000A7 that I want to grid drive, but have little circuit info available here. Most all my references have grounded-grid designs.Also I want to run a 304TL grid-driven.

[Opcom]

Thanks! I sent him an e-mail. I'm guessing that with some good advice and care for the tune-up it can be done.

Patrick

[W2PFY]

I have a 3CX1000A7 that I want to grid drive, but have little circuit info available here. Most all my references have grounded-grid designs.Also I want to run a 304TL grid-driven.

I would try to drive the grid using something like a MFJ small power antenna tuner if you don't want to take the time to build a grid circuit or just use a 50 ohm non inductive resistor from the grid to ground and drive the grid that way. You may not have to worry about neutralization in the latter configuration. My 2 cents worth.

[KM1H]

There is enough data in the spec sheet for grounded cathode, grid driven use in Class AB2 or C. For RF use it might require neutralization depending on frequency.

http://www.g8wrb.org/data/Eimac/3CX1000A7.pdf

[w1vtp]

Anybody remember the 3-1000Z finals at W1AW built by W6SAI?
That was a thing of beauty seeing them in the racks ready to kick butt.
I remember them lined up on a shelf in the basement when they were replaced by the Harris rigs. This was before my cousin was running the station. He suspects they evaporated. I told him that was their biggest mistake taking them out of service. They could have easily swapped over to newer tubes like 8877s or 3CX3000s

I wondered if I was the only one who asked to look downstairs at the old boat anchors.  Those were the days.

Al