[Amps] amp with push-pull output and magnetic coupling to the antenna

[Ron Youvan]

Gene May wrote:

> 1.  Does anyone know of a source for components or parts that could be used to make such a system?  I am willing to consider taking it/them out of existing assemblies (e.g., military surplus) but would prefer assemble it from "basic" parts.  I won't go so far as to say I'm desperate, but after considerable looking, I am very flexible and open-minded.

   B&W made "plug in" P-P coil assemblies in 100 Watt and 1,000* Watt sizes, I am looking for a set 
of each each myself.  The coil sets can all be plugged in and relay switched, my plan.
100 Watts is the input coils, I plan on grid driven and input swamped.

> 2.  It is necessary for the Q's of the tube circuit (probably to be around 10 to 15) and antenna circuit (probably to be around 1) to be compatible with the range over which the coupling coefficient between the two coils could vary.  As I understand, it is difficult to impossible to get coupling coefficients higher than about .3 using coils that would be compatible with the voltages and currents associated with an output of 1.5 KW.  Comments, please?

   The swinging link (or in the case of B&W a rotating link) adequately loads the resonant circuit.
These coils did not have the third harmonic suppression (the second harmonic distortion is canceled 
out by the P-P circuit) that we need now so it should be followed by a low pass filter for each band 
and the swinging link should be made from coaxial cable, the ridged mw kind the size of # 6 wire to 
minimize the capacitive coupling.  (Cross neutralization is required!  And Easy!)

   I plan (5 or 6 projects down the road) on using a pair of 4-1000s or Russian tubes class "B."
Another advantage of P-P is the absence for the need for a "plate choke."
   The 100 Watt coils plug into a 5 pin tube socket (like the 807)
The 1,000 Watt size (frequently used with a pair of 813's) connector was a row of (5 I think) male 
banana plugs.

* not 1.5 kW OUT size, 1kW INPUT size!
-- 
    Ron  KA4INM - If you have any criticism for me constructive or otherwise
                  keep it to yourself, at my age I just don't care anymore.