Topband: Re: Pennant Antenna with Remote Termination Control

[k6se@juno.com]

Andy Ikin wrote:

"Taking an other look at amplifiers for the Pennant.  I would suggest
using a Hi z input balanced J fet or mos fet amp directly at the antenna.
This would provide a good match to the antenna z and provide the 50 Ohm
feeder match.  More importantly, this would improve the common mode
feeder/antenna isolation."
==========
This was previously suggested by Bruce, AA4Z in his e-mail on 28 June
2000.  I thought his suggestion and K9AY's reply would be of interest. 
Here are those messages:

Bruce, AA4Z asked:

"Has anyone found a source for Pennent/Flag/Beverage antenna preamps with
a high Z adjustable input and 50 ohm output eliminating the need for a
transformer?"

Gary, K9AY replied:

"The scheme you propose may prove unsatisfactory.  The Pennant and Flag
antennas are independent of ground and must be isolated from the
feedline.  A preamplifier will almost certainly have a common ground for
both input and output, and thus, no isolation of the "cold" side.

A transformer with separate primary and secondary windings is required,
or an autoformer style transformer plus a choke balun. I suppose you
could use a choke balun on the feedline side of a Hi-Z input preamp, but
you were trying to eliminate the transformer so it defeats your original
purpose."
==========

73, de Earl, K6SE



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