1/4 wave ground plane for NOAA broadcast

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AronDouglas

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I finally finished this thing :) Now all I need to do is run 80ish feet of coax so I can mount it on the roof.

The vertical element is #10 wire with the insulation still covering it. Every other antenna I see that someone made is always a ground wire(copper wire with no insulation). I wanted a little more protection from the weather so I left the insulation on. I also wanted a little wider frequency coverage (in case I get more crystals for my scanner), so thats why I used #10 instead of #12 wire. The ground radials are 1/4" aluminum solid rods. Yes I know its a little big, but I could only get 1/4" ( I need 3/16"). I'll probably change it in the future if I find smaller aluminum rod.

The radials are attached to a 2"x2" aluminum square with the corners bent up at a 45 degree angle. I got the idea from a random Google search Help is On the Way The only downside to this design is in the construction, it takes a little skill to not break the aluminum plate when forming it and the aluminum rods dont like to be tapped for threads (they strip out easily).

















 

prcguy

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Wow, I think the ground radials and bracket could double as a jack stand for your car. It might be good to borrow or buy an antenna analyzer to make sure it resonates where you want since insulation over the wire will make it appear slightly longer than bare wire when used for antennas.
prcguy



I finally finished this thing :) Now all I need to do is run 80ish feet of coax so I can mount it on the roof.

The vertical element is #10 wire with the insulation still covering it. Every other antenna I see that someone made is always a ground wire(copper wire with no insulation). I wanted a little more protection from the weather so I left the insulation on. I also wanted a little wider frequency coverage (in case I get more crystals for my scanner), so thats why I used #10 instead of #12 wire. The ground radials are 1/4" aluminum solid rods. Yes I know its a little big, but I could only get 1/4" ( I need 3/16"). I'll probably change it in the future if I find smaller aluminum rod.

The radials are attached to a 2"x2" aluminum square with the corners bent up at a 45 degree angle. I got the idea from a random Google search Help is On the Way The only downside to this design is in the construction, it takes a little skill to not break the aluminum plate when forming it and the aluminum rods dont like to be tapped for threads (they strip out easily).

















 

AronDouglas

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Yep, an antenna analyzer would be nice to have. The sting form the radio bug is starting to take affect, so I'll be slowly buying more equipment as time goes by.

I live in the path of an international air traffic line (2 airports about 60 miles north and south of my house) so I'll be building an aircraft antenna some day. Then there is the CB base station that I'll be getting, plus I already made an off center dipole for the house scanner. And all that will go on the 40' tower once its set up. So yah, I'll be getting more tuning equipment some day.
 

prcguy

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If you don't have a ham license it might be something to consider since it would give you more options for making and using various antennas compared to CB. Plus you learn useful stuff while studying for the test.
prcguy


Yep, an antenna analyzer would be nice to have. The sting form the radio bug is starting to take affect, so I'll be slowly buying more equipment as time goes by.

I live in the path of an international air traffic line (2 airports about 60 miles north and south of my house) so I'll be building an aircraft antenna some day. Then there is the CB base station that I'll be getting, plus I already made an off center dipole for the house scanner. And all that will go on the 40' tower once its set up. So yah, I'll be getting more tuning equipment some day.
 

AronDouglas

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I still dont know if I'm going to get my HAM license yet, but I do plan on learning the test. The only reason I'm getting a CB base is because the work trucks have CBs in them...well that and CB is free :) I live about 3 miles from the Atlantic ocean and on some rare occasions when I'm listening to the CB range, with the BTC15X in the work truck, I pick up a few DX CB guys (one said he was pushing 1000 watts, he was talking to the west coast that day) .

Okay, I ran to the top of my second story house (about 30+ feet) and set a few screws to see how it looked and received. (I stood next to the antenna on top of the roof for these test). With my Icom IC-R10 in hand (radioshack collapsible antenna and GRE super amp) I could receive 1 NOAA station with close to half bars (that station is 40 miles away pushing 1000 watts). Next was a station 30+ miles away pushing 500 watts and I got almost 2 bars. And the third station is 60+ miles away with 500 watts and I got no bars and could barely make out words.

Then I hooked up the antenna to the Icom and I got full bars on all 3 stations. The station 60+ miles away was a little scratchy but it still came in nicely. I'd say it works :) Today was a nice and clear day with some spotty clouds, so with less favorable conditions and line loss I may not have such good reception.



The wire handing off the back of the mount is just the short piece I used to test reception. I will paint the mount, run and hide the coax later.
 

LtDoc

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Looks like it ought'a work just fine. Don't put too much faith in that 'larger conductor = wider band width', it just isn't quite that easy.
- 'Doc
 

davenlr

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Maybe if the conductor was 1/4" copper tubing :) AS for CB being free...well, there is no charge for Ham radio licenses. Granted the radios are a tab more expensive on the new market, but there are plenty of good used ham rigs for sale in the CB price range.

I love my CB in my work truck as well, so Im not a CB snob by any means, but you arent going to work skip to a guy running 1000w without breaking the law, unless you are just extremely lucky. With Ham radio, you actually can work the world on 4 to 10 watts, since there are so many more open frequencies to choose from, worked all states nets, and other opportunities.
 

LtDoc

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Copper tubing, or 4 inch pipe, or how about a 18 inch tin-horn? Don't waste you time, most of that 'wide-bandedness' is B.S.
- 'Doc
 
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