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Trying to rig a base antenna.

Help with installing an Antenna, or just choosing the right antenna to go with your radio, or your mobile.

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Chrisnick
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Trying to rig a base antenna.

Post by Chrisnick » Saturday, 25 February 2017, 17:18 PM

Ok so here is the deal. I am an apartment dweller and I am trying to rig up a base antenna. That won't get me busted.
So I have tried dipoles with crappy luck.

I have resorted to a mag mount on a piece or sheet metal. I cannot hear my buddy a couple of miles away, he can barely hear me. If I mess around and try to ground the antenna by running a ground wire to my railing or something I can get the static to drop but it causes my SWR to climb to about 2 1/2. No ground wire makes my SWR to drop to a better value but causes me to get a lot of static. I just can't find the in between. Weird thing is that the same radio and antenna on my car 30 feet away from my balcony booms. But as soon as I bring it onto my balcony it turns to crap.

Anyone know what I am missing?
My balcony has an aluminum floor. With iron railings. The balcony above also has aluminum floor. I know all that metal is not helping me. This is my last attempt on trying to get a base going in my apartment.

I looked at the NGP antennas but read they work horribly.

Thanks for any advice.


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Re: Trying to rig a base antenna.

Post by 443 Arizona » Saturday, 25 February 2017, 20:10 PM

do you have a tree or pole near your balcony? a rain gutter? you could string up almost anything if you understand the math. you might try building a simple dipole and clamp it to your railing, scrap off some paint to get contact to it and ground radio to it also. you could put a ~108" copper wire taped to your railing and put the magmount ant. in the middle,sticking out sideways and see what that gets ya,,, might be directional in the same way as the longer wire.
or, make a loop ant. with 108" circumference,,, keep researching , :cheers:

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Re: Trying to rig a base antenna.

Post by Dusteos » Sunday, 26 February 2017, 7:11 AM

You might try hanging a counter poise approximately the same electrical length as your radiating element. Roll it up when not in use.

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Re: Trying to rig a base antenna.

Post by 543FtWorth » Sunday, 26 February 2017, 15:01 PM

I posted a paint drawing of the apartment antenna I used to use somewhere online. It was a whip mounted to some pvc tied to the balcony rail. The pvc would put the base of the antenna at the eve of the roof and I ran a single radial tied off the the storage closet door. If there is a way that I can post a picture on this forum without resorting to a 3rd party FREE image hosting site I will be happy to share.

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Re: Trying to rig a base antenna.

Post by MDYoungblood » Sunday, 26 February 2017, 18:41 PM

543FtWorth wrote: If there is a way that I can post a picture on this forum without resorting to a 3rd party FREE image hosting site I will be happy to share.
543, you can use the "upload attachment" tab just below the subject text box, it doesn't require an outside pic poster. I drag the pic to my desktop and post them that way if they are too big for postimage.org .
Chrisnick, I have a friend that lives on a second floor apt. and he tosses a coax out the window to a antenna on his car, think he's using a tri-mag mount and a 102" whip now, does fairly well. Mounting one on the balcony with the aluminum overhead creates a problem, might have to lean it out away from the building as much as 45°.

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Re: Trying to rig a base antenna.

Post by Chrisnick » Sunday, 26 February 2017, 19:17 PM

MDYoungblood wrote:
543FtWorth wrote: If there is a way that I can post a picture on this forum without resorting to a 3rd party FREE image hosting site I will be happy to share.
543, you can use the "upload attachment" tab just below the subject text box, it doesn't require an outside pic poster. I drag the pic to my desktop and post them that way if they are too big for postimage.org .
Chrisnick, I have a friend that lives on a second floor apt. and he tosses a coax out the window to a antenna on his car, think he's using a tri-mag mount and a 102" whip now, does fairly well. Mounting one on the balcony with the aluminum overhead creates a problem, might have to lean it out away from the building as much as 45°.

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I thought of tossing a coax out the window. But am worried about some one tripping or complaining or whatever. Plus if I was gonna have to go out to connect and unconnected coax, I might as well just use the mobile.

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Re: Trying to rig a base antenna.

Post by 543FtWorth » Sunday, 26 February 2017, 20:12 PM

MDYoungblood wrote:
543FtWorth wrote: If there is a way that I can post a picture on this forum without resorting to a 3rd party FREE image hosting site I will be happy to share.
543, you can use the "upload attachment" tab just below the subject text box, it doesn't require an outside pic poster. I drag the pic to my desktop and post them that way if they are too big for postimage.org .
Chrisnick, I have a friend that lives on a second floor apt. and he tosses a coax out the window to a antenna on his car, think he's using a tri-mag mount and a 102" whip now, does fairly well. Mounting one on the balcony with the aluminum overhead creates a problem, might have to lean it out away from the building as much as 45°.

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Greg
I see it now. Thanks.
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Re: Trying to rig a base antenna.

Post by Chrisnick » Sunday, 26 February 2017, 22:04 PM

543FtWorth wrote:
MDYoungblood wrote:
543FtWorth wrote: If there is a way that I can post a picture on this forum without resorting to a 3rd party FREE image hosting site I will be happy to share.
543, you can use the "upload attachment" tab just below the subject text box, it doesn't require an outside pic poster. I drag the pic to my desktop and post them that way if they are too big for postimage.org .
Chrisnick, I have a friend that lives on a second floor apt. and he tosses a coax out the window to a antenna on his car, think he's using a tri-mag mount and a 102" whip now, does fairly well. Mounting one on the balcony with the aluminum overhead creates a problem, might have to lean it out away from the building as much as 45°.

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Greg
I see it now. Thanks.
Very cool. Thanks

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Re: Trying to rig a base antenna.

Post by MDYoungblood » Monday, 27 February 2017, 15:00 PM

What floor do you live on?

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Re: Trying to rig a base antenna.

Post by Scipio Kid » Monday, 27 February 2017, 15:20 PM

You have a unique situation. So you'll have to find a unique solution that fits your conditions. All these suggestions are good but might not work at your place. Your aluminum balcony might be a big asset or a detriment depending on how it's interacting with your mast. One of the best antennas I've ever seen was a 102" SS whip mounted dead center on a retired 40' semi trailer with a shiny, all aluminum roof. The radio was inside the trailer and that thing skipped all over the world and 40 miles any direction site to site with a stock radio shack desktop radio. The SWR match was perfect on all channels, no movement whatsoever. I'm no expert on radio waves but have seen the same results as you, having something that works great in one place, not work at all in another. I watched a vid on an apartment di-pole that worked great. I made one up exactly the same, put it in a similar manner on my home (where I have severe antenna restrictions with neighborhood covenants) and thought I was brilliant. But it pegged the SWR meter, and I mean pegged. The worst reading I'd ever seen anywhere on any antenna. (I broke the one on my truck and it still had a better match.) I don't know or understand why mine didn't work, only theories. I abandoned it and tried something else and got it to work, not great but it works. Now I'm experimenting with a different di-pole that started out bad but following advice from forum members, I'm now getting excellent RF from all over but the SWR is still too high; about a 2.3:1. Some say you can live with that but it only gets out a couple miles while my pickup, sitting 10 feet away will get out 10 -20 miles from the same location. I'm still trimming and modifying the mount, did a choke thing that helped and still have several other good ideas to experiment with. Don't give up. You'll find something that works. When you do, share it with us so we can learn from it too.

Another suggestion here, I had a third story apartment in the 70's when everyone had radios and base stations etc. I had access to a machine shop (but you could make it in a garage) and made a bracket to bolt (screw) to the aluminum window frame and set a small (automotive) baseload antenna out about 10" from the building wall, away from the aluminum window frame about a foot. It was inconspicuous enough that I never got in trouble, had about a 1.5:1 match and and it got out pretty well. Worked great for the 2 years I was there leaving only two small holes in the aluminum when I left. I can't remember that far back (or anything past 15 minutes anymore) but I had to experiment with the ground plane, using steel and aluminum radials, grounding it to the plumbing etc. and found a match that passed for the conditions and had fun using it. I'd always talk to my wife when she ran errands (no cell phones back then). She'd call me from the grocery store to see what I wanted or just to tell me to shut up. Everyone in the complex thought we were rocket scientists. (Actually, I think she was ... while I majored in ballet.) (That's a lot funnier if you've seen me.) I had a buddy in another building put a similar antenna on his window mount air conditioner and it seemed to work great too.

Well good luck on it and let us know what you come up with.
Happy Trails



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Re: Trying to rig a base antenna.

Post by HomerBB » Monday, 27 February 2017, 20:21 PM

If you are on an upper floor make a dipole,

Cut a piece of metal tubing, aluminum, steel, copper, etc, 8' 7" long and mount it as a flag pole on an outer wall with one of these made from plastic:

Image


Cut a very thin piece of wire for the other end of your dipole. attach it to the plastic flag pole holder allowing it to hand down along the wall.
Attach the braid of your coax to the hanging down wire where it's attached to the flag holder, the coax center wire to the flag pole tube.

Should work well.

It can work on a lower floor, too, except you may need to angle the lower wire of the dipole at a slant to keep it off the ground.

You can use a dipole indoors, too. run each of the wires at an angle attached to a wall to shape an upside down (inverted) V - ꓥ - with the coax attached in the middle of the vee.
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Re: Trying to rig a base antenna.

Post by Scipio Kid » Tuesday, 28 February 2017, 8:21 AM

Great idea. This Dipole works for a lot of guys. But I tried it on my house and it was a disaster and I couldn't figure it out. I tried everything I could to fix it but nothing worked. I've concluded it's because I have stucco exterior and under the stucco is chicken wire and under that is wall board with a foil covering. I figure all that reflection just screws the antenna up beyond recovery. I was hoping the reflectivness of the wall would help it work as a directional antenna down the canyon but, like I said, it won't work. Amazingly, It receives beautifully, better than anything else I've tried but I can't get the SWR's down to any acceptable level to transmit. When I do my SWR goes up to about a 3:1 and my normal 4 watt output jumps to 11. At first I thought this was good but apparently all I'm doing is overdriving my amp and I'll fry it if I keep it up. I also tested actual performance and I can't even hear it a few blocks away. I'm thinking I'll make a bracket to move it off the wall a foot or two and see what happens but that'll have to wait until the snow is gone and today it looks like it'll be around forever.
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Re: Trying to rig a base antenna.

Post by Chrisnick » Saturday, 18 March 2017, 12:29 PM

I am going to try to ground the sheet metal that the mag mount antenna sits on. That is my last effort. After that I think I have exhausted all other ideas.

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Re: Trying to rig a base antenna.

Post by 543FtWorth » Saturday, 18 March 2017, 16:10 PM

Chrisnick wrote:
Saturday, 18 March 2017, 12:29 PM
I am going to try to ground the sheet metal that the mag mount antenna sits on. That is my last effort. After that I think I have exhausted all other ideas.
A tuned radial might help you if you have room. Attach it to the sheet metal or better yet the base of the mag mount so that it is directly bonded to the coax shield. Tie it off with some string so it doesn't touch anything and trim for lowest swr, I'd start with 9 feet. You can use thin wire so it's almost invisible. I've ran 100 watts through a dipole made of 20 something gauge mag wire.

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Re: Trying to rig a base antenna.

Post by Chrisnick » Sunday, 19 March 2017, 16:14 PM

Well I tried to ground the sheet metal with no real improvement. I think my ideas of having a base have been dashed.

I guess I will do all my chit chatting in the mobile.

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Re: Trying to rig a base antenna.

Post by 543FtWorth » Monday, 20 March 2017, 4:47 AM

An antenna doesn't necessarily need a ground to function. Think of what you're trying to set up as a variation of a dipole. That's why I mentioned the radial, you're missing the other half of the antenna.

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Re: Trying to rig a base antenna.

Post by Scipio Kid » Sunday, 26 March 2017, 21:55 PM

Don't give up! Figuring out how to make it work is half the fun of having it. I put a 96" fiberglass whip on a firestik Mag mount right in the middle of my A/C condenser and got a near perfect match without any further tuning. It gets out good, not great but good and that's fine while I experiment with a couple of different dipoles I'm working on. And I can talk from home to any of the mobiles for testing.

Keep working on it, you'll come up with something that works.
Happy Trails




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