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 Antenna ideas anyone?

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willy3486



Join date : 2012-10-30

PostSubject: Antenna ideas anyone?    2012-10-30, 4:54 pm

I want to make some type of antenna for my hallicrafters and am radios to use. I picked up a nice Rohm tower that is about 30 feet tall, 2 sections and a top piece. I am trying to figure out how to set it up to be used the best. I have no power lines where it will be, I live in the country. I want to make a hinge for it so I can raise it and lower it with a hoist. I a not looking to buy a antenna but I wouldn't mind making one if I need to. I do have a old analog TV antenna on a pole now. One of my Halicrafters I have used in the past I could pick up short wave all over the place.

So here are a few of my ideas. I can use a some porcelain insulators at the top and then use some of them on posts to tie the guide wires to. Then I could connect those guide wires that are insulated to the tower to a cable and run it in to use as a antenna. That way I could get 3 or four wires up in the air 30 feet for a antenna. The other thing is to just use the antenna I have and put it at the top. I also have a antenna rotor I used in my attic before I switched to satellite. I could do that or a combination of both.

I want to set it up so I can pick up AM and shortwave better. I don't want it to be only for am or a specific shortwave. So is there any suggestions on how I could set up the antenna for all around use?
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Cliff Jones
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Join date : 2010-11-22

PostSubject: Re: Antenna ideas anyone?    2012-10-30, 7:48 pm

insulators are not usually designed for antenna support. But it is feasible.
I would think a single would be the simplest. With on the feed end at a minimum height of 10 feet from ground height .
Since the length isn't critical anything over 50 foot would be desirable.

Just realize that the tower would effect directional receive patterns.

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willy3486



Join date : 2012-10-30

PostSubject: Re: Antenna ideas anyone?    2012-10-30, 8:53 pm

I am wondering if I would be better off to use the old TV antenna I have and the rotor. I could turn the rotor the direction I need. I had thought about running a wire from my workshop to a old barn about 75 feet away. That was before I got the tower. I was able to get quite a few short wave radio stations with the original halicrafters I had with just a small extendable antenna on the back, no external one. I was happy with it to a point. I also would like to get am and fm a little better.

Its been so long since I studied antennas I can't remember much. I learned how to calculate all the formulas on designing them in school but that was over 25 years ago. So do you think I might be better with just a antenna I can rotate? I am not looking to get every station out there just to get some reception from outside my shop. My shop outside is all metal and it blocks almost all signals. As far as the antenna goes now I have its not that bad, its only about 15 feet off the ground and barely goes above my roof. It still doesn't go higher than my house, the tower probably would . If I did use the antenna and rotor I have most of the stuff now I need and I could properly tie it down.
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Cliff Jones
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Join date : 2010-11-22

PostSubject: Re: Antenna ideas anyone?    2012-10-31, 11:45 am

Just something to think about, the length of the antenna has a direct correlation to its efficiency in terms of gain. I have thought of trying a multi-wire antenna off the same feed, so that way you would be close resonance on some of the bands.
tie point = O insulators for spacing so wires they don't touch each other from wind=8
Receiver____________O__________________________________________________________8
2nd Receiver wire____> \8____________8____________8_________________8
3rd Receiver wire_____> \8___________8______________8
the O being the tie point With insulators or spacers holding each separate but to the same connection wire.
As far as FM unless you are trying to get distant stations which are only line of sight anyway you are wasting effort other than a stronger local fed signal to your radio or TV, The problem with the new digital TV signals is that the old beam antennas had two different arrays, the longer for the now defunct analog signals (which have been moved to the higher frequencies) and the smaller array which all the signals of DTV are tuned to. So even though you have the older style, only half of elements are being used.

As far as using for short wave, you would be better off using the shielded coax as a vertical antenna going up the tower to the TV antenna. The shield would be connected to the antenna connection which should be ungrounded. Then use a separate wire to ground. The inner core wire is of no value because its shielded and useless this way.

If you are not using coax but twin-lead then it is acting as your antenna for short wave, because it is longer and picks up more signal than the TV antenna itself. However try the rotor and see if you have an improved signal strength as it to may be of help, but it wont be tuned to shortwave and you may notice no diffidence in directionality.

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shaidorsai



Join date : 2015-06-03

PostSubject: Re: Antenna ideas anyone?    2016-12-07, 9:00 pm

Attach a pulley to the top of your tower (hopefully before you raise it) with a loop of rope long enough to reach the bottom of your tower with a few feet to spare. Your best bet for simple installation would be a sloping center fed dipole as long as you can fit in your space.  Attach the center of the dipole to each side of an insulator (long wire broken in the middle by the insulator).  You don't mention transmitting, so feed it at the center with a long piece of TV Twin-lead.  Long enough to reach your receiver.  Solder each side of the twin-lead to one leg of the dipole where it is broken in the middle by the insulator.  Tape it good to the insulator to relieve strain.  Hoist the center insulator to the top of your tower.   You could also use coax, fastening the shield to one side of the dipole and the center conductor to the other.  Fasten insulators to the ends of your dipole and attach the insulated ends to something convenient that spreads the ends as far apart as space will allow.  Leave a small amount of slack.  Don't worry about cutting it to a resonant frequency just put as much wire in the air as possible.  This will vastly out perform your TV Antenna rig.  -Good Listening!
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wildcat445

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Join date : 2014-08-16

PostSubject: Re: Antenna ideas anyone?    2017-05-03, 4:47 pm

When I lived in Phoenix the best antenna I had was a Slinky that I threw down the stairs to my garage.  I connected the top end to the radio and let the rest of the Slinky lay on the stairs.  Another suggestion I read one time was to chuck up a 1" plastic pipe into a drill press chuck and slowly wrap 100 feet of telephone cord wire on the pipe.  You would have six small wires in the long telephone wire.  You would tie the six wires in the phone cord in series.  This would give the equivalent of a 600 foot long antenna.  IIRC, the pipe was three feet long.  I thought that sounded interesting, but I have never tried it.

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