D&A 12 tube phantom arcs over on high

[Onelasttime]

The 4CX250 requires much more HV plus a screen supply. Grounded grid isn't impossible but problematic. Grid driven through a swamped input is much easier.

The EU equivalent is the EL/PL 509/519 beam power pentode. These work well with the available 1K HV. There are many articles on their use throughout web as there still exists a 400w power restriction on "the" Island.
https://pa0fri.home.xs4all.nl/Lineairs/Frinear400/frinear400eng.htm

Any of the horizontal deflection amplifier tube (sweep, Novar, beam power pentode) based amplifiers are a relic consigned to the past and thankfully so.

I'll repeat that the proper disposition of any of these death traps is to part them out completely and sell any good tubes.
The Iron will always come in handy. The rest is scrap.

Which "the" Island are you refering too with the 400w limit? Thanks!

 

[Captain Kilowatt]

Which "the" Island are you refering too with the 400w limit? Thanks!

I believe he is referring to Great Britain.

 

[giboni]

No time to go thru all these Posts. tie point

1 Warrior
7x Phantom's & PDX400 in my collection.

Big problem with all of them.

1) The main load air variable condenser or capacitor. It is an AM/FM air variable.

Receiving air cap ? This gremlin Hv Arcing in this component reared its ugly head.

Repeatedly. In my Phantom to Warrior conversion. Went thru 3 of these. Could be a

post in itself. Solved it by using two. Transmitting A.V.C. With slightly larger spacing.

between the tuning plates.

2) Underneath chassis.

For reasons unknown to me. gues. Is dust buildup, rust thru the paint ?

Arcing starts from a soldering post to chassis. Once it starts . Tape. Liquid insulation.

Nothing stops it at that spot. Only solution. Is to move that hand wired post to a new

spot,

underneath the chassis. I surmise. That carbon buildup on the chassis where it arced

creates this problem. One last thought. If the main RF Tank coil is severely out of

"Resonance". This will start this arcing process. Every time U change out more than

two tubes in the "Finals". 8. Unless you have ORIGINAL marked D&A 6MJ6 .

The Final RF Tank Coil. Must be re-tuned. Or replaced completely.

Link to Phantom Promotion To Warrior. Might be of help. Maybe tonight will post

the new pics and Mods to this ongoing project. Yup. the Phantom image has a strong

back light. OEM Green !!!!

https://www.worldwidedx.com/threads/d-a-phantom-12-tube-promotion-to-warrior-high-drive-2017.223127/