Re: VTTC output

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Herwig Roscher by way of Terry Fritz <twftesla-at-uswest-dot-net>" <herwig.roscher-at-gmx.de>


Ed Phillips wrote:

> Unfortunately, there is a bigger problem with VTTC's than all of 
the above, which primarily applies to an amplifier coupled to a 
resistive load.

Ed,

Besides coupling there seems to exist another problem:
Normally oscillators use a very loose coupling between plate and 
grid circuit in order to get a pure sine. For stability reasons the load 
is held as small as possible. Therefore buffers, drivers and/or 
amplifiers are used to connect the signal to the load.

VTTCs employ power oscillators with relatively tight internal 
coupling. They are operated in C mode mostly and are SELF 
REGULATING. So if you changed e.g. the coupling between 
primary and secondary the oscillator changes its Q point. And this 
may change the output power and lead to wrong conclusions. 
Obviously there are lots of nonlinearities and mutual influences.

These are my 2 cents and critics are welcome of course.

>  Bottom line is that educated cut and try is probably the only 
practical way to go.
- That's a clear word, Ed.

Regards,

Herwig