> But what happens if you want full power in ONE yagi?
> Power combining at a common point would seem likely to result
> in some of the power going into the second amp, rather than
> the antenna. That's where my intuition goes a bit South.
If impedance and phase are correct there's no problem to parallel two amps
like it happens with antennas, put in parallel and then match to the load.
This perfect impedance and phase between two PAs is not so easily achieved
as one migh think, and a certain power surely doesn't go where whe should
like it goes.
Within certain limits this fact is acceptable but mistakes or failures may
happen and the parallel system may result in a destructive condition for
PAs.
It's a good practice, practically a must with solid state modules, to use a
wilkinson power combiner instead of paralleling.
A dummy load able to withstand half the power the single unit is required
with the wilkinson, if everything is perfect no power flows in the dummy, if
one amp is dead (or off) half power the good one goes to the load..
73,
Mauri I4JMY
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