Home |
Search |
Today's Posts |
#8
![]() |
|||
|
|||
![]()
On Fri, 03 Apr 2009 00:36:10 -0400, Tim wrote:
Ok, looking at fig. 6 of the pdf, 4 bands,2 wires. I assume that the long top wire is somewhat resonate on 40 and 15, with the clipped wire being for 20 and 10. That means one wire is both 1/4 and 1/2 wave. Hi Tim, I already offered my best guess on that. Conversion of feet and inches to meters gives the story. I should have looked better at that because I am picturing a 1/4 wave vertical with a half wave radial...Or with rf, wouldn't that matter? It is only half the story. What the vertical element offers is the other half. The natural presumption is that it is a quarterwave in its own right, but with HF Multibanders, that can be a presumption too far. As they are generally loaded for the lowest band, tuning is difficult, narrow, and performance seems to suffer there (from my own experience with a GAP and other's reports of theirs). So then on my triband vertical idea, I would be better off staggering radials around in a fan shape, say one every hour of rotation, (3 bands, 4 radials) and have four resonant radials connected by some insulating material for mechanical stability. Harder to make but easier to tune. Going to look like a multi band vhf antenna on steroids, but as long as it works...... It probably won't be as easy as that, but it won't be as hard as anything any more cute. Even then, the shortcuts often work if you observe all the "gotchas," which usually means lifting the contraption into the air 10 feet or so. 73's Richard Clark, KB7QHC |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
10m - 40m non resonant vertical | Antenna | |||
Resonant radials | Antenna | |||
Resonant and Non-resonant Radials | Antenna | |||
Resonant frequency | Antenna | |||
RESONANT ANTENNAS | Antenna |