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Author Topic: 12 or 15 Meters?  (Read 4611 times)
N5INP
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Posts: 1276




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« Reply #15 on: January 30, 2014, 01:09:54 PM »

Looks like it's going to be 17m and 12m -  Cheesy

I'm working outside as we speak but I'll explain why I went with 12m this evening - it's weird ...
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N5INP
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Posts: 1276




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« Reply #16 on: January 30, 2014, 03:11:02 PM »

I thought this would take half an hour ...

So I did the calculation and added enough wire to the 10m dipole (which is below my 17m dipole) so I should have been able to trim back and get a good swr on 15m. But it didn't happen. I never got anything close to a dip near 1:1, and my swr was also affected on 17m.  I was using my Comet ant. analyzer and while trimming I went past where it should have been correct. I thought I wasn't paying attention so I actually started over with a new piece of wire, but the same thing happened.

After two hours of this I finally decided to keep trimming until I got to the next band (12m). As I cut more and more wire, I got better and better dips as the resonant freq. went up, and the 17m dipole started acting better too. Finally, I got a very nice 1:1 swr at 24.960 MHz, and my 17m dipole was back to normal.

So I don't really know what was going on, but I suspect that it had something to do with the geometry of the two dipoles and some sort of interaction between 15m frequencies and the chain link fence below both dipoles. Perhaps this particular ensemble of physical properties and the fact that 17m and 15m are "close" that I just couldn't achieve the desired results.

In any case - hello 12 meters!  Cheesy

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N0IU
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« Reply #17 on: January 31, 2014, 03:48:26 AM »

What about 20m?  It is open far more than 15m.

Well, a local ham told me he stays away from 20 M because of all the nets and crowding.  Sad

What kind of stupid convoluted logic is that? Yeah, that's what you want to do... stay away from 20 meters because there is a lot of activity on it!

That reminds me of the famous Yogi Berra quote... On why he no longer went to Ruggeri's, a St. Louis restaurant: "Nobody goes there anymore. It's too crowded."
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W4XK
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Posts: 61




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« Reply #18 on: February 01, 2014, 07:47:41 PM »

I'm surprised no one has offered a reasonable solution for your questions. Put up a piece of wire as long and as high
as you can. Center feed it with 450 ohm window line, connect to a tuner and enjoy trying out all of the bands that it
will tune on until you decide on what's best for you. Then concentrate your efforts on that band. That's what I use, and
work the world on all bands 80-10. Enjoy!

Bill, W4XK
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G3RZP
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Posts: 4842




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« Reply #19 on: February 02, 2014, 12:13:22 AM »

Lower loss than window line and less affected by weather is a true open wire line with spreaders every two or so feet. Otherwise, do as Bill says.
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K1PJR
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Posts: 148




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« Reply #20 on: February 02, 2014, 03:27:43 AM »

Try an end fed long wire. Mine is 124 feet and I can work 10-160. Is it resonant on all bands? No. Is it the "best" antenna? No. Does it work? Very well! I use a Palstar tuner and have no issues achieving a 1:1 SWR on all bands. I've logged 40 countries and 24 states with casual operating. The best part is I'm having fun  Cheesy

Ditto what Bill said. Forget all the nit picking trimming. It doesn't matter. As long as your tuner can get a match your on the air. Just get a bunch of wire in the air as high as possible and go from there. You will be amazed.
« Last Edit: February 02, 2014, 03:37:28 AM by K1PJR » Logged
KC8Y
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Posts: 257




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« Reply #21 on: February 02, 2014, 07:21:26 AM »

RE K1PJR:   do you have any grounds on the end-fed? how high is it?  type of wire (insulation on wire)?  is it a name-brand of antenna?  Interested in it.
I have a high-power tuner. 

Ken KC8Y
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