[Amps] Soft Tubes?

[TexasRF@aol.com]

In a message dated 3/28/2005 10:54:45 P.M. Central Standard Time,  
W4EF at dellroy.com writes:

Good  point, Gerald. A more likely explanation for the low efficiency
on 10  meters might be a combination of higher tank circuit losses
and wattmeter  calibration error.

Still, I hear people talking about "soft" tubes a  lot. I can understand
broadcast pulls have low filament emission, but aside  from that
are there any other mechanisms which will result in  diminished
output capacity from a tube like the  8874?

Mike,
W4EF........................................................................
.

-----  Original Message -----
From:  <TexasRF at aol.com>
>
>
>
> And this brings up the  question: Why would a soft tube show up on 10m
> operation and not lower  frequencies?
>
> 73,
>  k5gw






Hi Mike,
I didn't intend to question the validity of soft tubes showing first at  
higher frequencies. I have always been under the impression that this is true  but 
just now wondering why it might be true or even if it is true.
 
73,
Gerald/k5gw