HFU HF Underground
General Category => General Radio Discussion => Topic started by: draadloos on September 12, 2009, 2242 UTC
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What's the best to transmit to you folks in the lower 48?
A Horizontal or Vertically polarized signal?
(New to this)
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Thanks Ragnar, you'll be hearing from me ... ;D
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Hey I got a listener!
You know of course- dipoles are some what directional, with the signal transmitting at right angles to the wire. I have read that receiving is better parallel to the wire but I have found this to be less true in practice.
Be listening for you.
RD
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Specifically, I want to try an antenna design of mine I call a framed Yagi.
It would be hell of impractical usually because it has to be suspended between to points (hills in my case)
and as such can not be rotated. However, because of my location (Tundra) all the DX'ers are south of me
so I have no need to rotate.
The Antenna is simple enough, two non-conductive rods run the length and the reflector, directors and driven element are attached between. This is super cheep to build but tricky to setup, and since it will be cut for 6.925Mhz it will be big (around 22 meters squared). I've had success with this design on the 2 and 6 Meter Ham bands, I just wanted to know if I should set it up flat or vert for you folks south.
Thanks again Ragnar, I've been listening for a while and it was a thrill to hear my question on your podcast.
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I'd go flat, as you are going to need the ionisphere to hit the lower 48. Figure at 6925 that you get roughly 300-miles a bounce :o and when conditions are super good, 600. Vertical gets eaten up with noise, QRM and everything you can think of ::), plus you need a good ground plane if you intend to do vertical. Wouldn't hurt with the horizontal either but most definitely for the Vertical. Plus for a structure as big as you describe, you need Belden 9913 or something similar to feed and some big-time power.
Post your design, if you don't mind, would love to see it! :D
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What you are proposing sounds a lot like the TCI 527 wire log periodic antenna.
http://www.tcibr.com/?PageID=203
I have used the TCI antennas, they are amazing, and really hold up over the years. Performance is outstanding!
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A 3-element, 40M ham antenna may be a wee more practical though.
Peace!
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But, if you don't need to turn it, the wire log periodic is a lot cheaper and will stand up to wind and weather a lot longer. Besides, they look so dang cool.
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...and will stand up to wind and weather a lot longer.
THAT is a big plus in an antenna on the tundra.
(they do look cool. CFB Aldergrove had a few 3-12 meggers up when they were a relay station to NZ)
Peace!
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That's a cool antenna TS, thanks for the link
I need to stay low profile on this as the Hams around here are very Fascistic.
I dont plan to leave the antenna up when I'm not transmitting.
Thanks for the info Mr. Burnz, makes good sense.
I'll post my designs ASAP.
P.S. I'm planning to use a free-banded FT-897, but I'm wondering if transmitting
for 30-min without pauses will fry it. Any thoughts?
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If you need stealth, think about wire dipoles instead of any kind of directional antennas.