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  #51  
Old 07-12-2009, 04:22 PM
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Quote:
Originally Posted by W5LZ View Post
Don't get too worried about a dipole being directional. That depends a lot on how high the thing is. Until it get's above about 1/2 wave length above ground, it isn't all that directional at all. Even if it's very high, that directional thingy is never a 'spot light', more like a 'flood light', pointed in two directions.


- 'Doc

I'm starting to see this...its not all that directional.

Even with only a calculated 3.85 watts, I'm not having trouble hitting local stations...the real local stations are a little harder, but those around the 10 mile mark seem to be just fine. And that's even to a station almost off the tip of one antenna (the direction that should be "weakest").

Could this be the result of the "drooping"?
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  #52  
Old 07-12-2009, 05:19 PM
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"Could this be the result of the "drooping"?"
No, not really. It has more to do with a dipole not being all that directional even when it's high. Some, sure, but not nearly as much as people think. there are directions where there is 'less' signal, but very seldom ever places where there are no signal at all, until you get quite a distance from the antenna (as in more than several miles, plus or minus who knows how many miles). That doesn't take into account any obstructions that can affect a signal either. How much will an obstruction affect a signal? It ranges from no affect at all, to completely stopping it, and everything in between. Don't ask me, I have no idea about what may be around your antenna. And the biggest thing to worry about is if you've P.O.'ed 'Momma Nature', you -really- don't wanna do that!
- 'Doc
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  #53  
Old 07-21-2009, 03:36 PM
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Finally got it "done". Replaced some hardware with stainless. Sealed the coax better with heat shrink and silcone sealer. Cut some limbs back (they didn't seem to affect anything, but they were there so I hacked them).

Unfortunately, to make this vertical I would need to either relocate the antenna or have a professional tree trimmer come in because the limbs that interfere now are over 50 feet up (I live at the top of a steep bank)...well out of my reach.

Couple noteworthy observations...

Its not as directional as I initial thought. As Doc indicated, they are somewhat omni-directional. I have talked LOCALLY from the "tips" so-to-speak. I have made several ground plane contacts, ranging from under a mile to around 20 miles (as the crow flies)...all but two were mobiles, so they were most likely vertical. All this at around 14 feet to the feedpoint.

I have been able to talk skip on SSB and AM easily with only barefoot power...I am very happy with that since it seems to take at least 50 watts in the mobiles to do much on the fly. Once I get this Washington aligned and tuned, I should be good to go.

I have not heard from anyone that I am causing interferrence (TVI or otherwise). Most around here are on cable, but I know that unless they replaced their cable wiring, it is really bad. The coax in my house had been run through a drilled hole in a header and beaten to 90*s using a hammer, then stapled...every single one was like that, and it was only RG-59(?).

One more question (assuming best case for this antenna system). I have around a 1.5:1 SWR. Didn't someone indicate that was "the best" I would see due to the difference in the feedpoint resistance (around 70 Ohm) and the radio (50 Ohm)?? I know I could "improve" my SWR slightly because it is different on channles 1 and 40, but still under 1.6 at its worse.




Last edited by The Jerk; 07-28-2009 at 07:42 AM.
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  #54  
Old 07-21-2009, 09:54 PM
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There really isn't that much difference between an SWR of 1:1 and 1.5:1, practically speaking. Depends on how you get that 'improvement'. If it's at the expense of the resonance of the antenna, it isn't worth the effort at all. Nothing wrong with that 1.5:1 anyway.
- 'Doc
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Old 07-21-2009, 10:01 PM
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Quote:
Originally Posted by W5LZ View Post
There really isn't that much difference between an SWR of 1:1 and 1.5:1, practically speaking. Depends on how you get that 'improvement'. If it's at the expense of the resonance of the antenna, it isn't worth the effort at all. Nothing wrong with that 1.5:1 anyway.
- 'Doc
I fully understand that 1.5 isn't bad, but that "should" be the best I would see with a typical SWR meter?? Because of the mismatch??

I am not going to change anything...not for the miniscule improvement I might see. Just was thinking out loud I guess...
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