Plate load Z? =? loaded B+ / (1.8 x? DC plate current).?
On all those old amps, the higher voltage was always 41.4 % higher than the lower B+ setting.? ?The DC plate current was 41.4%? higher, when in the higher B+ setting.?
You can use different V ratio's as well.? ?IE:? ?1/2 the loaded B+? and 1/2 the loaded? DC plate current, and now you have 1/4 the power.
You can use any B+ ratio you want.? ?( as long as the current ratio uses the same ratio...which implies careful control over the drive levels).
In all cases the plate load Z? remains the same.? It works superb.?
?And works much better? if using lower power data modes.... vs? using the existing high B+ rating......and reducing plate current in 1/2.? ?That fubar method results in doubling the plate load Z.......? which then screws up the tank values.? Double the plate load Z, and you now require? 1/2 the value for the Tune and load caps..... and double the uh on each band.? ?Since you didn't do that, the tank Q just doubled =? lousy tank eff....and circulating RF current in the tank coil and bandswitch remains the same.? And with data modes, the average dc plate current is double that of processed? SSB,? so now the amount of watts? dumped into the poor tank coil and bandswitch has quadrupled..... and you just cooked the bandswitch.? ?It's just I squared x? R.? ? In this case it's? RF current? squared x? ESR? ?ESR is effective series resistance...aka? RF resistance.?
IE:? Ameritron? 'big 3'? amps being driven to 1/2 plate current...... while stuck using the oem? B+.?
