[ARC5] Transmiitters: Parameters: A suggestion.

[Kenneth G. Gordon]

On 21 Mar 2016 at 20:30, Dennis Monticelli wrote:

> Data from a T-22 measured in 2001.  All measurements key down.
> 
> Vp = 468V 
> Ip = 106mA
> Screen = 245V
> Osc - 210V regulated via VR tubes
> Grid bias = -52V across 16K (measured the R)
> Grid current = 3.25mA
> Coupling control at max
> Pin = 49.5W
> Pout = 27W  (54% efficiency)

Perhaps if you reduced the grid resistor to about 12 K from 16 K your efficiency MIGHT 
improve slightly, although, as you say, 60% is pretty darned good.

You might simply parallel the 16 K resistor you have there with a ~48 K resistor, which will 
give you 12 K. That way it would be easy to reverse.

Doing that would reduce your grid voltage to ~ -45 VDC at 3.25 mA, which would be exactly 
the "book" value.

On the other hand, "if it ain't broke, don't fix it". :-)

Ken W7EKB