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THE AM BULLETIN BOARD => Technical Forum => Topic started by: W1UJR on June 08, 2005, 12:12:28 AM



Title: Mast Materials?
Post by: W1UJR on June 08, 2005, 12:12:28 AM
Hi guys, in need a simple and cheap 20-30 foot mast for my new 6 meter antenna.
I tired thin wall electrical conduit, the couplers are too weak and snap on the trip up.

Any one have any suggestions?
I was thinking 1 to 1 1/2 inch stee pipe, but ???

-Bruce W1UJR


Title: Mast Materials?
Post by: w3jn on June 08, 2005, 06:55:09 AM
Radio Shack 10' steel TV masts are cheap and strong.  They fit together nicely also.

73 John


Title: Mast Materials?
Post by: K1JJ on June 08, 2005, 11:07:28 AM
Hi Bruce,

For a 30' strapping mast, take a look at PVC pipe. If you
start with a 20', 3" diameter and slip in a 10', 2 1/2"
[or whatever you decide upon] you will find it is pretty
sturdy.  Schedule 40.

A friend of mine did a 50' mast using that stuff and it's still
up supporting a heavy wire load.

To interface each section will take a little sanding of the
smaller section, but they will work- and slide together. Bolt
3-4 times with 1/4" bolts.

73,
T


Title: Mast Materials?
Post by: Ed/KB1HYS on June 08, 2005, 04:57:13 PM
PVC is good if you guy it well. Don't know about UV though. A coat of varnish would probably keep it well.
 
The handbook shows an easy wood mast Three 2x4's in an A frame arraignment.  (the A is the base and the 3rd extends from the point, the legs of the A are pinned to uprights in the ground to rotate the mast) another one to guy well.

You may try the local Fence Company,  get some tubing they use for Chain link fence top rails or posts. Many Sizes to choose from, heavy and well galvinized comes in 20 ft lengths.  Some types will have one end necked down to insert into the following end.  Drill a few bolt holes and Viola!


Title: Mast Materials?
Post by: Ed KB1HVS on June 09, 2005, 08:32:09 PM
I bought this  over this winter for a yet to be erected antenna project (this summer?)They seem to be quite sturdy and pleasing to the eye. Ill take some pics and send them to you. The mast kit I got is a little different than this one but the mast itself is the same.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4672&item=5780611905&rd=1


Title: Mast Materials?
Post by: Jim, W5JO on June 09, 2005, 10:28:48 PM
If you want metal, go to a company that sells irrigation piple.  Seems they are 20-25 feet long and already swedged to fit together.  Another possibility is metal guttering like you have on downspouts from your house gutter.

You will have to guy both, but binder twine won't fall apart in the sun.


Title: Mast Materials?
Post by: W1UJR on June 10, 2005, 07:25:23 AM
Tnx guys, that was helpful.

What I have done, just for the moment, is lash the antenna to the top of a 26 foot extension ladder.
The ladder is lashed to the railing on the back of my barn.

I best thing is for me to put up a tower/rotator ssytem, but I really don't want to do that until I get the barn replaced.


Title: Mast Materials?
Post by: Ed KB1HVS on June 10, 2005, 03:42:17 PM
Ha! A good "temporary " JS  8)


Title: MAST
Post by: flintstone mop on June 25, 2005, 08:11:48 PM
Halo dear friends
I always use aluminum schedule 40 masts. I think I was using a 20 foot long piece for a mast through a Rohn 25 top section while the the rotator sat in its little nest. The diameter was 1 7/8 inch or 5/8. Great stuff! Price was around $100. It won't break , believe me.

Fred


Title: Mast Materials?
Post by: K8SWL on June 25, 2005, 08:26:35 PM
Try fence rail for chain link fences, cheap and quite strong for 20-30 foot.
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