[TowerTalk] coax switch at tower

[K7GCO@aol.com]

In a message dated 12.06.00 19:49:55 Pacific Daylight Time, 
jskatz@sk.sympatico.ca writes:

<< 
 I want to feed each band on a triband quad band separately. Also, I am
 going to use a four square 40 m slopper and feed the tower as an 80 m
 vertical.  The distance from shack to the tower is about 50 ft. The
 height of the tower is about 60 ft. Any suggestions for a design that
 will minimize the cost of feedlines, switches, connectors etc for this
 antenna system?
 
 tnx
 Sylvan
  >>
Feed each DE of the triband quad separately and with balanced feed to prevent 
the "Dreaded RF Spill Over." and not exciting the other off band quads that 
occurs when all the DE's are tied together. That design concept has set the 
quads performance potential back more than another other concept and used by 
the Junk Merchants catering to the tight budget market.  That design is in 
the "Top 5 All Time Dummities Of Antenna Design".  You will need a remote 
controlled coax switch at the top of the tower for this.  Antenna Mart has 
the good ones.  Early quads had marginal mechanical construction.  Antenna 
Mart makes the strongest ones now.

If you feed the tower as a vertical, RF spill over on to the rotator cables, 
HF coax etc can occur and get into everything in the shack.  Ground the 
shield of coax at the base of the tower and by pass each rotator lead with a 
.1 ufd to the base of the tower also.
A Johnson Match Box and open wire line is a great system for wire antennas.
K7GCO

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