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Home made mast for inverted 40-80 meter dipole

Oct 12th 2017, 11:44

k9zzp

Joined: Nov 26th 2013, 18:05
Total Topics: 0
Total Posts: 0
Hello,
I am trying to put a dipole in my garden and feed it with coax into my den. I have an attic dipole system upstairs that works ok but not great. I will not be able to go upstairs this winter and would like my station on the first floor. I have Antenna tuner at my radio and will use that to adjust if I need to.
I would like to make a 40-80 inverted vee. The 80 meters will be coil loaded.
I plan to use electrical conduit PVC as a center mast. A metal pipe will be pounded into the ground about 3 or 4 foot tall, and the PVC bottom pipe will be 2 1/2" by 10 foot long. A piece of 2 1/4" PVC will fit inside and either be clamped with screw clamps or through the pipes with a set of pins to hold at the right height. The 2 1/4" will fit 4 feet into the larger 2 1/2 leaving 6-foot exposed.
Guy ropes will be a little less than 10 foot high.
The same method and heights for other pipes down to 1" top piece. The top piece will be filled with four feet of pipe and a fiberglass rod at the top. The dipole will be pulled up with rope and pulley. This puts the top about 35 feet. (Unless I can't add.)
I know not all of the pieces will slide into each other without adjustment to outside diameter of a couple of them. I have a plan to reduce the size of those problem pieces.

Am I on a fool's path? Could this work? Ideas?

Thanks,
Mary
Oct 12th 2017, 15:28

W1VT

Super Moderator

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
http://forums.qrz.com/index.php?threads/35-pvc-antenna-mast-tower-ideas.286123/
Discussion of this on qrz.com
Oct 13th 2017, 06:59

N8CMQ

Joined: Feb 28th 2011, 01:24
Total Topics: 0
Total Posts: 0
Hi Mary, Jeff here.

What is your expectation for the antenna?
Are you looking to increase performance as well as to get it outside for the shack move? If so, you may be disappointed.
At that height, you will see little improvement, and it may decrease performance due to many factors.

An 80 and 40 meter dipole or inverted V will benefit from height. The apex height isn't what you need to worry about, but,
the overall height. You would want a minimum of 1/4 wave length, with additional height being better.

If you are unable to do that, an alternative is a roof mounted mast and the antenna suspended from there.
I am not sure if you have a single or multiple story house, but any additional height will help.

If that is daunting, then a ground mounted vertical 1/4 wave with lots of radials would be much easier!

N8CMQ
Oct 26th 2017, 19:25

k9zzp

Joined: Nov 26th 2013, 18:05
Total Topics: 0
Total Posts: 0
My goals are to get a better antenna and for time being fed into first floor. My attic dipole system is not great but it does work.
I have a story and a half so right now attic is maybe 20 foot tall.
I have given up on the pvc mast in the garden idea and I have now decided to go with a 40/80 coil inverted v dipole over a walnut tree branch. I have a pretty tall walnut tree close to my house. How high I get the dipole will depend on which limb I can get a line over(35 or 40 foot).
I want to go with a north-south line and I still need to measure how far I need the end supports from the tree.
I was talking to my tree guy and he was telling me that the tree was a hundred foot tall. I looked at him sideways and told him that there was no way it was a hundred, maybe 50. Anyway, he wants a thousand to remove it. If this dipole works, removing the walnut tree would give me a good place to put a simple tower or mast.

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