Thoughts breing here. I came across 2 102 inch whips adjustable ball and spring mounts. Plan on putting one if not both on the roof of my house. Wich would be the best set up? Use both in a dipole configuration? Or use one and make some sort of ground plane for it? Could the tv antenna be used for ground plane? Any input would be great.
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Help with ground plane for 102 inch whip
- Thread starter Jlwhitt77
- Start date
Dipole - Inverted V/Horizontal/Vertical - are all good options and more straightforward that a ground plane, but even that is easy to achieve.
How high will it be?
What are your communication goals, local, DX, combo ? (DX on 10/11m bands will be limited for a while due to poor propagation)
How high will it be?
What are your communication goals, local, DX, combo ? (DX on 10/11m bands will be limited for a while due to poor propagation)
1m guessing 20 to 25 feet maybe 30. Peak of roof on a ranch home and another 10 feet up from there.
Dual use but more for dx. I live way out in the stix and not many cbers around.
Holy crap! Thanks for the link. Lots of technical Information that i have yet to make sece of. I did see that antenna height can be fairly low for best performance. I did manage to get antenna up. The way it is on the ball mounts it can easily be changed to any configuration. V, horizontal, vertical, ect. ect. I did put an ugly choke on it. 5 turns around 4 inch pvs at the feed point. On initial Swr test, a little over 3 on ch 1 and well over 3 on ch 40. What im dont understand is how to tune a dipole. Do you shorten and lengthen the antenna that has the center feed from coax only or both? Hmmm. More reading today.
Start by getting rid of the springs. They aren't useful for a base install, and make the antennas too long. Find a dipole calculator online and it will even give you lengths and angles for inverted vee. The whips do need to be shorter for inverted vee. Should be around 102.5 flat, and 97.5 in a vee.
I think this is always said because of mobile installs with less than ideal mounting, and no bonding. It's a glass half full situation. Someone else may think their antenna is too short, but I see my ground as lacking. A dipole shouldn't have ground issues, therefore the math should be close.
468÷27.385= 17.0896
17.0896÷2= 8.5448
8.5448 x 12 = 102.54 inches per leg. Unless I made a mistake?
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Yes you do need the spring to make the 102" length. I was unable to get an acceptable SWR with this dual inverted v setup. Didn't want to cut down my whips so I aborted this mission. Put the radio back in my truck with the 102" antenna and have a flat SWR. Will work on a base setup at another time.
So your whip itself is 96" and you have to add a 4" spring to make 102"? Most guys claim a 102 whip plus a spring and ball mount for 108" total. My whips are very close to 102 by themselves.
You know, Im not sure what the original length was. I acquired 2 of these. They came off some old junk pick up trucks.