PAR antenna on 80 meters

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PAR antenna on 80 meters

K. Rice

Hi Grif -

This is an interesting idea, but when I try to sketch out the schematic, it looks
a little odd to me.

The Par transformer is either a true, flux-coupled transformer with a ground
return connecting the ground sides of the primary and secondary windings, or
it's an autotransfomer with a similar ground return.  The little voltage
measurement test I did a few years back doesn't  discriminate between the
two designs, but it is one or the other.  (The case is sealed with epoxy.)

The Par is a broadband design, given that there's no capacitor to tune when you
change from a half-wave wire at 40m to a half-wave wire at 20m, for example.

If you short the primary and connect a counterpose at the rig, you end up
with the transformer's secondary in series with the antenna, and with complement
current flowing on the counterpose.  

The problem is that any magnetic flux generated by currents flowing in
the secondary induces current in the (former and now shorted) primary
where it will be dissipated as heat.

I may not be thinking about this correctly - I welcome any critique of
this analysis -- but it seems to me you might do better with a non-resonant
(say 44-foot) wire connected to the coax connector's center pin and with
a 1/4-wave counterpoise connected to coax connector's ground.

The latter arrangement should tune well with most simple L network autotuners and might
turn out to be more efficient.

73,

Ken
K3VV

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K2/100 SOLD

John L Merrill

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