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Author Topic: Antenna height on a shoestring budget  (Read 1122 times)
WO1VES
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« on: March 11, 2008, 06:48:53 PM »

Hello everyone,

I'm fairly new here, so I hope this is the right forum for this question.  Basically, I want to know, what is the best way to get an antenna up as high as possible with as little money as possible?

Here is some background.  First off, my money is very tight.  Lets just say I helped my sick cat "fight the good fight," which he ultimately lost.  But he left me with a sizable debt due to vet bills.  So there really isn't any play money available.  Currently, I have a quarter wave ground plane made out of coat hangers.  I have it mounted to a vent pipe on my roof, but the top of the antenna is still below the peak of the roof.  It is also very rusty, and is getting on time to be replaced.

My birthday is coming up in less than a week, and I'm going to have a little money available.  A friend offered to sell me his diamond dual band vertical.  I think it will be a great replacement for my current coat hanger antenna, but I'd love to get it up higher.  I'm very limited by my budget, and the fact I don't own the house I'm living in.  No drilling holes in the roof, etc.  Any suggestions?

Thanks everyone, now if I could only figure out how to put up a tower in my back yard.  :-)

Brian Gudzevich
WO1VES
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WB2WIK
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« Reply #1 on: March 11, 2008, 06:58:35 PM »

You didn't mention the bands, but I imagine it's VHF and for a dual bander VHF-UHF.

All you need is a set of chimney straps ($9.95 to $12.95) and a longer mast, maybe a 10' "TV antenna" mast, to get you up 10' above the chimney.  The mast should be about $9.95.

All of this is available from Home Depot, Lowes or many other multi-purpose supply houses.

"Height above ground" means *everything* on VHF!  For every extra 5' you can increase antenna height, at an average location, you can work out about another 10-20 miles farther.

Your working radius is directly proportional to antenna height.  If you could place your "wire hanger" vertical 100' above ground, you'd be very impressed with what you can work.

WB2WIK/6
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N6AJR
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« Reply #2 on: March 11, 2008, 07:10:12 PM »

go for a 20 , 30 or 40 foot push up mast, and a bracket to the eves or a pipe in the ground to set it in and a couple of rope guys.. lots of ways, even three 1 X 4 boards  8 feet long in a A frame  tower.

here is some pics of my mess

 http://hometown.aol.com/catfishtwo/N6AJR.html
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W5FYI
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« Reply #3 on: March 11, 2008, 08:33:14 PM »

Check on galvanized fence rail. Our local Lowes has swagged sections as long as 10' and 20' each, in 1 5/8" diameter, all in the under-$20 price range. Radio Shack should have wall mounts, eave mounts, chimney mounts, tripod roof mounts, telescoping masts and 5- and 10-foot 1 1/4" steel mast sections.
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K5YF
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« Reply #4 on: March 11, 2008, 09:39:49 PM »

Hello Brian,

Welcome aboard!

Taking for grated that we are talking about VHF and/or UHF...

The previous comments are spot on. Higher is better.

The rusty coat hanger: Actually, the rust on your antenna isn't a huge deal unless there is a LOT. Even then, some gentle sanding with cheap sandpaper will take care of that. Add some cheap black spraypaint and you are good to go.... If the coat hanger antenna happens to be a vertically oriented j-pole and you are working mostly VHF/UHF FM voice or packet, for sure just clean it up and paint it. So long as it is in proper working order.

Feed line loss at VHF and up can be the killer. If you are using RG-58 or RG-59 type coax, spend your money on some good Flex LMR-400 or something similar. It will make a lot of difference. Its a LOT heavier too, so that is a consideration for my next suggestion.

If you have trees and your antenna can handle the stresses, shoot a 1 oz lead fishing sinker (painting it bright orange or yellow really helps to see it after shooting) into a tree using a wrist-rocket slingshot. Medium-light fishing line tied to the sinker (a big bonus is to have the fishing line on a reel) will allow you to pull a light rope or cheap String Trimmer Line back over. Tie the rope/trimmer line to your antenna and pull it up as high as you can. >>>cheap twine usually doesn't last more than a couple of months, but the trimmer line will last a couple of years<<<
>>>buy extra sinkers! You will likely lose a couple<<<

Twin lead J-Pole antennas are GREAT for this. Just remember that the wind will blow so leave some slack. Don't forget to account for the weight of feed line stress on the rope/line and also the antenna.  

I hope this helps you Brian. Best of luck and enjoy!

-Brandon
-N5JYK

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N5LRZ
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« Reply #5 on: March 12, 2008, 04:12:57 AM »

TREES, Natures Towers

N5LRZ

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WA3SKN
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« Reply #6 on: March 12, 2008, 04:56:26 AM »

You don't mention frequency, but building an antenna is cheap!  Just some wire and wood will do.  Sounds like you want something for FM/repeater style operation.
You DO want to get away from rusting steel... you can generate un-intended harmonics with it!
So, verify band(s) and mode please!

-Mike.
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AD4U
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« Reply #7 on: March 12, 2008, 07:51:54 AM »

Trees make good towers for VHF antennas, but there is another alternative.  Down here in 4 land there are stands of bamboo all over.  Many bamboo stalks grow over 50 feet tall and are quite thick at the butt end.  

Back in the 1960's when I had no money and was a new ham, I cut a few, left the "limbs" on them, and drug them home behind my car (was never caught by the cops).  The "limbs" got abraided dragging 10 miles down the highway, but they protected the main stalk.  When I got home I cut the limbs off and I had an instant tower.  

I dug a small hole beside the house, put the butt end in the hole, and made an eave bracket to secure the bamboo to the house about 10 feet above the ground.  The bamboo usually lasted two to three years.  I put a pulley on top and used a small nylon rope to pull my dipoles up and down.

You can mount a small VHF vertical on top of a bamboo pole, if there is any bamboo in "0" land.  The best part is the cost is absolutely zero.
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WO1VES
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« Reply #8 on: March 12, 2008, 08:08:14 AM »

Thank you everyone for the great replies!  This site is a wealth of information.  Sorry for not mentioning the bands, yes it is 2 meters/440.  I want it for local repeaters, as well as distant signal work.  For example, with my current antenna, I managed to work a guy 30 miles away on simplex with 100 mw.  Ignoring the fact he had a beam on a tower, I'm wondering what I could do with a higher, properly tuned antenna.

WB2WIK, I like your idea of putting a mast on the chimney.  I'm wondering if the antenna is light enough, if I could get away with a 20 foot mast?  The top of my chimney is not above the peak of my house.  My house has a section where it is only one floor, that's where the chimney is.

N6AJR, you're yard must be the envy of all your neighbors!  :-)  As mush as I'd love to put up a 40 foot push up mast, I'm sure they are out of my budget.

W5FYI, Interesting though on the fence rail, if I could find something for that price.  Sadly, I drive a Ford Escort, so I have no way of getting a 20 foot section home, but I suppose I could attach two or three 10 footers together, and somehow attach it to the side of my house.

Brandon N5JYK, thanks for the welcoming!  The coat hanger antenna is a ground-plane.  I had it down last summer, because the house was getting a new roof.  That's when I noticed how rusty it was.  I cleaned it up with sand paper, but that didn't help much.  Next time I have it down, I'll try your spray paint idea.

For the feedline, I'm actually using RG-8.  I picked up a 50 foot role with connectors at Radio Shack for $10 on clearance.  So whatever antenna mast I choose has to fit within the 50 foot range.

As for hanging it in a tree, I'm not sure if I would be thrilled about the idea of handing a vertical antenna and heavy feedline from fishing line over peoples heads.  And I really don't want it swaying in the wind.  Though it probably would work very well for the HF antenna I just built myself a couple days ago.  I've been wondering how I would get that into the tree.

I know twin-lead J-Poles are great!  I use one with my VX-2 all the time.  That was an option I was considering before my friend offered me the vertical.

N5LRZ, yes I have lots of trees in my yard.  Sadly, the only tree that isn't on the other side of my property from the house also has the power lines running right through the center of it.  Discretion must be used when placing antennas in this tree.  I don't have enough feedline to reach the other trees, and as I said, I really want a stable vertical antenna.

Mike WA3SKN, the only problem I have right now with building antennas is I don't have an SWR meter, so I can't tune them.  I lucked out with my coat hanger antenna, in that it works almost perfectly.  It seems my other antennas drain the battery on my VX-2 a lot faster than the ground-plane.  I suspect that is a good indication of the SWR levels.

That's why getting that other antenna from my friend is a good idea, I know it works, and it's tuned.  And it has some gain to it too.  I'm currently using an HTX-242 with my roof mounted antenna.  But it has an intermittent PL tone issue.  I'm seriously considering replacing it with a used dual band HT.  I'd like to see how much I can do with half a watt vs the 10 watts I'm using now.  But it sure would be nice to do it with a better, higher antenna.

I also use this setup with an experimental RF link to echolink, that I leave running during the day when I can monitor it.  I use that with my VX-2 around town.  But as stated, the 242 puts out 10 watts.  That's a lot more power than I need for work around town, and I'm worried I'm annoying people miles away that I can't hear with my 2 meter link.  I'd feel more comfortable with a half watt on a better antenna.  Since I seem to be a QRP kind of person, that is also a plus for me.

Thanks for the great advice everyone!  I hope this reply wasn't too long, I wanted to cover all posted points.

Brian
WO1VES
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WO1VES
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« Reply #9 on: March 12, 2008, 08:21:11 AM »

AD4U, I'm actually in New England "1" land.  Being Winter, there isn't any bamboo available, but in the summer, my uncle's yard is usually over grown with it.  But it never grows quite as big as what you described.  I've never seen it reach 10 feet.  It sure would be nice if I could find it here, I like that price.

Thanks,

Brian
WO1VES
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AD4U
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« Reply #10 on: March 12, 2008, 08:30:36 AM »

Brian:

You don't need a SWR meter to build a 1/4 wave 2 meter ground plane antenna.  Make the vertical rod 19 1/4 inches long and out of brass brazing rod.  Solder this to the non-threaded end of a SO239 coax connector.  Make four "radials" each around 20 - 21 inches long.  Solder them to the four holes in the SO239 and bend them down about 45 degrees.  Attach the PL259 from your coax to the threaded end of the SO239.  If you do this, the SWR should be about perfect, and this antenna will perform just as well as any commercial 1/4 wave antenna, regardless of the price.  How and where you mount it is up to you.

Dick

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WA3SKN
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« Reply #11 on: March 12, 2008, 09:34:37 AM »

OK, 2 meter and 440 Mhz FM.
Beware of coax losses at 440 Mhz.  So keep the length limited to 50 feet.  Now, how high can you get with that limit?
You are probably best off with a groundplane or vertical "fan dipole" antenna.  You can have a vertical element cut for 2 meters and another cut for 440 Mhz in parallel with the same groundplane, or just vertically mount the fan dipole... again 2 dipoles in parallel.  There is some inter-action, but you can get the VSWR down to a reasonable level fairly easily!
So, how high can you get with the 50 ft limit?  From the radio, how much horizontal run do you have before you run vertical... and anything available to mount it on?

-Mike.
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WO1VES
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« Reply #12 on: March 12, 2008, 12:24:39 PM »

Mike,

Limiting myself to 50 feet of coax is no problem, as that is all I have.  From my estimates, I need about 25 feet of coax to get from my radio to my current mast.  If I reroute to my chimney, that adds an extra 5 feet.  My house is all asphalt shingles, roof and walls included, so clipping the feedline to that would be no problem.

My current antenna is up at 20 feet.  It is attached to a rather tall vent pipe near the base of the roof, 10 feet above.  I'd love to bring the new one up to 30 feet.  I seem to have a few options for the mounting.  I have the chimney on the other side of the roof from my window.  This is a large chimney attached to the side of the house.  It goes from ground level to about 20 feet up at the peak.

I could stay attached to the vent pipe, but that would limit my hight to 20 feet as it is now, since I don't think the vent could handle a 20 foot mast.  Another idea I thought of, is I could attach the mast right to the side of the house, sitting on the roof of the lower portion, climbing up the side of the upper portion.  This could be fixed to the side of the house up there, if I can find a mounting solution and mast that wouldn't cost a lot.  Would this be a feasible solution to hitting that 30 foot mark?

If it would make it easier to understand what I'm explaining, I can go out and get a photo of the roof area I'm talking about to show what I have to work with.

Thanks,

Brian
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WA3SKN
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« Reply #13 on: March 12, 2008, 12:55:27 PM »

Chimneys are fairly weak, but would support a small 2 meter/440 antenna OK.  The smoke and gasses emitted can be a problem.
Vent pipes are EXTREMELY WEAK!  You don't want to have one break!  Replacement can be difficult.
I think your best bet would be mounting to the side of the house.  A couple of TV style masts or some 2x4s bolted together would make a fairly cheap and effective solution.  The antenna itself could be made of wire with little problem.  Check the local hardware stores for possibilities.
Spring is coming.... Antenna time!
73s.

-Mike.
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W3LK
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« Reply #14 on: March 12, 2008, 01:55:13 PM »

Backing up Mike's comments, I wouldn't put anything bigger than a 2m ground plane on a 5' mast on a chimney - ANY chimney. Chimneys are designed to support themselves and nothing else. They have very little lateral or torsional strength.

If the chimney is an active one, even a furnace, the flue gasses will destroy any antenna in a couple of years, or less.

If there simply is no other choice, then the mast MUST be guyed. Otherwise you run a very good chance of the chimney failing and good luck trying to get your homeowner's insurance to pay for it.

73,

Lon - W3LK
Naugatuck, Connecticut
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