Topband: 1/4, 1/2 or 5/8 vertical summery
Richard Cariello
rcariello at si.rr.com
Thu Jan 12 21:05:12 EST 2006
Thanks to all that replyed.
Well it seems the 1/4 wave vertical wins.
Score:
7 for 1/4 wave
4 for 5/8 wave
1 for 1/2 wave
1 for a single Delta Loop.
I would have thought that the 1/2 wave vertical would have come in first with the lack of a good ground radial system I alway thought the 1/4 wave and 5/8 wave performance was very dependent on the radial system.
Consern about feeding the 1/2 wave was mentioned. ON4UN's book describes a tank circuit with a 49 uh coil and a 160 Pf cap. I have used this simple tank tuning circuit in the past. It worked very well. Could anyone comment on the possable loss from this type of tuning unit. The coil I used had 1/8 inch silver plated wire.
Once the balloon is off the ground it dosen't seem to matter how high it goes. In fact after it gets past the 125 foot mark it seems to stabilize, at least in this area. Getting the current node of the antenna up away from the ground has always looked good to me. Where and how well the first hop is made can't be controled.
We are useing an inverted L off the tower with about 80 feet of the wire vertical. It seems to be doing the job but we are hopeing to get something better. I'm not convinced that a 1/4 wave balloon held vertical will do that much better then the inverted L we are now useing. We may have to fly two balloons and phase a set of 1/4 wave wire verticals to start seeing an improvement. We have a set of phased 80 meter 1/4 wave wire verticals being held up with trees. This antenna dose a very good job.
By the way. A Delta Loop is very possable but there isn't enough time to put it together for this contest season. I tried one on 80 meters during a Field Day. Very good performer.
Also we expect to use the 80 meter phased array as the receive array for 160 meters this season.
Thanks for the great reply. The information has been a great help.
Rich AA2MF
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