[Amps] 4-400A low output, VU3RAZ problem

[Roger (sub1)]

On 3/31/2011 6:13 PM, Carl wrote:
> Ummm, you guys are beeing very selective in the spec reading department.
>
> For AB1 the max is 800 and typical is 750. For AB2 the max is still 800 but
> the typical is 500 since the tube is being run harder; 800V would likely
> exceed the anode dissipation with full drive and loading.
>
> OTOH, for Class C AM its 600/500.
>
> But what do hams care about ratings....run then until the anodes get a hole
> in them.

Were you looking over my shoulder when I fired up my first 6C21?   I 
didn't even get to "He" out of "Hello Test" and half the plate was 
gone.  Bright too! <:-))  But what the hey... Back then they were $5.00 
or less and readily available.
Unfortunately I had to disassemble the 800 ma plate current meter to get 
the needle off the peg.  IIRC the 6C21 being the pulse modulator version 
had something like a 30A cathode emission capability which might exceed 
that 600 Watt (?) plates ratings just a tad at 2800 V.

73

Roger (K8RI)

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