[Boatanchors] AM tubes and power levels (Was insulated shafts)

[Carl]

> On Wed, Aug 25, 2010 at 12:48 PM, Carl <km1h at jeremy.mv.com> wrote:
>
>>> Does a pair of 810s x a pair of 4-250s qualify? How about 2 450TH x 2
>>> 450TL? I'm really bad at math. (o:
>>
>> The former is a wimp, thats what I ran as a teenager. The latter just 
>> falls
>> short at 360W but you have been granted a waiver, I'll expect payment at
>> Nearfest. My 2x 250TH + 304TL's at 355W also needed a waiver but the 
>> pending
>> upgrade to 6C21's walks right in. Various combinations of 304TL's and
>> 4-1000A's gain you instant admittance. A 3CX3000A7 qualifies all by 
>> itself.
>
> Can't remember what the big ceramic jobs are that are still in
> storage, 3CX2500s I think. Stock tube for the 21E. Think they draw 7
> amps or so.
>
> Isn't a 6C21 basically a 450 rated for pulse service? Can't remember
> the mu, maybe medium, between the TH and TL?
>
> Don't forget to adjust for elevated line voltage.
>
> We'll sort this all out at the Friday night AM Dinner @ NEAR-Fest.  :D


The 3CX2500 has the same filament as the 3000. 7.5V @ 51A

The 6C21 has the same dimensions and anode as a 450T but a 8.2V @17A 
filament which is very close in emission to a 750T. For some strange reason 
Eimac only rates it at 300W PD in GG via an old Bill Orr blurb. Others rate 
it at around 600W with some air and I know several who ran them on AM with 
6KV and they survived. They werent a good SSB tube.

I also remember one very famous W1 who ran a pair of 750TH's on 75 SSB with 
10 KV on the plates and driven with a 30L1 and 75S something or other.