[Antennas] Dipole "Multi-band" pairs?

Wed Nov 30 16:35:13 EST 2005

The ARRL Antenna Book (1984) shows a very easily home-built lightning protector for open 
wire lines on page 8-26 (fig 21 & fig 22). Nothing like it in the newer publications from 
ARRL. If anyone needs a copy I can send by e-mail direct.
This is the way i bring my o/w lines into the shack:
	The lightning protection (mentioned above) is mounted on the shack wall just above the 
holes through which the leads are brought through the wall. From the lightning protector 
into the shack I use coax cables (a pair of them) one for each wire of the two-wire feed. 
The shields are left floating at that point.
	On the inside the shields are connected together and grounded to the tuner chassis and 
ground lead, the inner conductors are connected to the 2-wire output of the tuner.
	There is no need to worry about the difference in impedance between the 450-ohm line and 
the dual co-ax, the tuner takes care of that.
	My present set up is 300 foot center-fed wire up 50 feet at the center and about 12 feet 
on the ends. The feeder is about 80 feet long. Note: if the tuner will not match on some 
frequencies, try adding 10 or 12 feet to the feed line. That will do it in most cases. For 
best results, the feed line should be brought off the center of the antenna at right 
angles as nearly as possible.
Harvey/W4TG