[Boatanchors] Knight TR-108 question

[Bill Cromwell]

On 02/09/2014 10:47 AM, Wally Gibbons wrote:
> Good morning,
> I have a friend with two of these, and we've been trying to figure out why
> the rigs only put out about 3 watts. The output power isn't stated in the
> manual.
>
> Anyone have one of these? Are you getting 3 watts out, or more?
>
> Seems like a 2E26 should do more like about 10 watts or so.
>
> Thanks for any input you can offer.
>
>
> Wally Gibbons, AF7FH
>

Hi Wally,

There are already good replies about what a 2E26 can do in those radios 
on AM. I have some that I run conservatively in class C on CW. The specs 
show that applying maximum B+ and biasing it hard into class C and then 
applying sufficient drive it should make 27 watts. That's leaning on it 
*hard*. I run mine more conservative and with 300 volts on the plates 
and two tubes in parallel I'm making 10 to 15 watts. I plan to increase 
B+ a little (but not for maximum smoke) and try to get 20 to 25 watts 
from a pair of them.

How much smoke (B+) do those transmitters use? And then consider the 
factors for AM use as opposed to CW.

73,

Bill  KU8H