Pulled the Television Yagi down this evening..

[ve6pg]

..gud luk geo...all this messing around, wont werk..best you should have gotten a light bulb and put that up there...why ask, when you dont take advice from the guys who have done this, fer 40,50, 60 yrs?...i guess next is something like a square wheel... geez...the guys here are the best, and you wont read/listen to what they suggest...and btw, it is not illegal to get into other folks tv, audio etc...who told you this?..it is their fault, if your station is clean, but again what do i know...only had my ticket since august 26, 1975...when there was a real exam...10 wpm cw receive and transmit, plus written theory, and knowing the federal radio act...no a/b/c/d crap...

...sk..

  ( that means signing clear, in CW)...
..and further, if you are not an advanced class ham in canada, you are not permitted to work on any transmitter, or have an rf output beyond 560 watts p.e.p. ..i'll look you up, and see...



..sk..

[VE3GZB]

There's no need for such bitterness.

I have to work within what I can afford, work within what materials are available to me in my area - because shipping costs will eat up the budget too quickly - and I have to work within the space I have.

I cannot put up a full length dipole for 20m because I don't have the linear space from my tower to the power lines, and I don't believe I have the necessary antenna construction materials and experience for a first time tower antenna project to put up something more complex like a Moxon design and expect it to remain up, in one functioning piece.

There are too many points in the practical construction of a Moxon which depend on maintaining fairly constant dimensions relative to other components, something that is not so easy to maintain up on a tower in a high wind.

After all, the last thing anyone wants is to wake up after a rain or wind storm at night and see pieces of their antenna in their neighbour's window or car windsheld.

I explored different ideas presented here, I weighed them against what would fit here and what I can afford and I brought these ideas to Bob at Maple Leaf Communications, who is also a ham and has a wonderful array of antennas on his property. We discussed which would be most practical based on what materials I could afford in my budget and a short dipole is what we ended up agreeing upon.

73s geo VE3GZB

[ve6pg]

geo, you are right, and i apologize...you want wire?..tell me...i've got miles of the stuff... i was thru grand valley twice on friday...might be thru there next week...i'll drop it off..you dont need to be there, i'll just leave it on your porch, or whatever...how about a half wave, dipole for 20, coax fed, as a sloper?...off the top of your tower, running at a 45* angle, facing into europe?..

..sk..

[K1JJ]

I'm using along the fiberglass poles a parallel pair of my favourite wire, speaker wire, coiled every 5", held on with nylon tie wraps and outdoor RTV silicone.

Geo,

Your idea of winding helical linear coils onto the fiberglass poles will work fine. It will give you a shortened 20M dipole as you desire and will have reasonable efficiency.

As for tying down the wire coils to the fiberglass rod, I would suggest using black electrical tape wound tightly over the wire.   Then spray it with a can of clear epoxy, the stuff you can find in any hardware store. This will seal it and keep out the rain.  

The tie wraps and RTV idea you mentioned above will break down and fall off within 5 years from UV and wind. Plus it is not as clean looking or smooth for wind.

Using the antenna analyzer will work fine to tune the coil lengths and then seal them off tightly with electrical tape and epoxy spray. There are other spray products that are good for the WX too.

* Be sure to tune the dipole at the center without using feedline. A short 3" temporary jumper coax is OK, but keep it short for 20M. Feedline will add errors in the initial tuning. The dipole center is the truth. Keep the ends away from objects and at least 10' off the ground when tuning it.

BTW, I think coax would be a better bet. Coil up about six turns at the feedpoint and this will prevent feedline radiation. Then you can tape the coax to the mast and run it anywhere.   You can connect the coax directly to the 50 ohm rig output with no tuners.

The problem with the speaker wire is it is balanced and sensitive to all objects. You will need to run it isolated an inch or so from all objects for the full run to the shack, just like the old TV twin lead days. Plus it will need a bal to unbal transformation at the rig. (tuner or balun)

I'm sure someone has some coax they can give you for the project.

Take a few pics and post them when you get it built.

Good luck.

T

[KB2WIG]

  "  I'm sure someone has some coax they can give you for the project. '


I dont know 'bout u, but jest about any home i've been in has lots 'o cable tv coax in the cellar, basement, attick walls, etc.   U just gotta mine it, rip it out and use it... its all over the place, and FREE if you get it...


I ran zip cord fer a feeline, outdoors, fer a few years..... it werked; but appropriate feedlines will werk beter.

gud luck,

klc

[ve6pg]

..geo..i might be going thru grand valley this week...do you need some wire?..understand, i've been picking this stuff up for 40yrs, and i dont want anything for it...as a ham, if a guy needs something, tubes, antenna parts, wire, etc., and i dont need it, i pass it along to anyone who requires it...this comes back, in kind..some day i might need something, guys have helped me...it is an unusual group...there are guys who will take advantage of course, but by and large you will find guys are willing to just say "take it, you need it, i dont"...
..again, i drive thru grand valley often..you want/need some wire, just say the word...

..tim..

..sk..