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Old July 8th 07, 02:24 PM posted to rec.radio.amateur.antenna
Jimmie D Jimmie D is offline
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First recorded activity by RadioBanter: Feb 2007
Posts: 287
Default ADF NDB beacon antenna change seeking comments


wrote in message
oups.com...
We are going to drop using the shunt feed tower no matter how hard we
work on it we don't think it's going to work any better that it does
right now.

We have two choices :

We have two towers spaced 250 feet apart the towers are 95 feet
high. We could install a 'flat top' wire run it from tower to tower.

The horizontal run tower to tower would be 250 feet : The vertical
drop to the ground would be 90 feet or so.

The vertical wire would be connected to the flat top wire dead
center

We could series feed it against a good ground; 8 to 15 radials 500
feet long


Choice two:

We have two towers spaced about 140 feet they are 150 feet high The
'flat top' wire would run 140 feet horizontal tower to tower The
vertical drop would be 150 feet. same as above vertical wire
connected dead center of flat top.

series feed working against 8 to 15 500 foot ground radials.


My question to the group:

Is it better to have more (150 feet) vertical wire in the air with
LESS (140 feet) flat top wire or :

LESS vertical wire in the air (90 feet) but MORE flat top wire 250
feet??????


The flat top wire is insulated from the towers using power line
fiberglass rods

NDB freq is 529 KC

P.S.

Would their be a big difference if the 'flat top' has two runs of
3/8 aluminum cable side by side spaced about 30 inches ?? or
would one 3/8 cable do the job???

Thank you for your input

Dave WA4SZE


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