Alliance tenna-rotor for beam?

[Slim]

It's not what you think! I'm thinkin of tryin to use one of these as a way to rotate a set of Maco 104's or 105's from vertical to horizontal and vice-a-versa. If some of you old schoolers out there remember these rotors,they had the "mast thru mount" configuration.I was thinkin of "adapting/reducing/enlarging" the boom to fit this rotor and thus have the vertical/horizontal option w/out the expense of that big ol' Yaesu rotor on the market! I'm gonna try it come spring and will let y'all know what comes of it.Not enough time before the snow flies here this year.I'm gonna try it w/some spare boom parts I have here and my experimental 15' tower on the shed before I go up the 40 footer and try it for a permenant install tho!!! I was just curious if any of y'all tight-wads (like me) have tried this? Also,I thought if I were to go w/the 105 beam I may be able to forgoe the additional boom support (guy wire) and have enough support if I were to use galvanized pipe (8'-10') as the pass thru boom section adapted to the factory boom? Just a BrainStorm I recently pondered about.Appreciate any and all input anyways!
Happy DX'in.Slim CDX285

 

[W5LZ]

Slim,
On a smallish light weight antenna, maybe (big 'maybe', sort of). I don't remember 'Alliance' ever making such a 'pass-through' type rotor, though.

As for a heavier boom, just remember that the increase in weight will probably be the determining factor. There really is a reason that manufacturors don't use thicker walled pipe instead of larger diameter. Part of that is weight but the 'biggy' is the strength of the boom.

Ought to be an interesting experiment.
- 'Doc

Nothing wrong with being 'frugal', but it has to be balanced with practical.

 

[Jay in the Mojave]

It's not what you think! I'm thinkin of tryin to use one of these as a way to rotate a set of Maco 104's or 105's from vertical to horizontal and vice-a-versa."

Hello Slim:

Your leaving a lot of stuff out of the picture here?!?!?!
You say a set of MaCo 104's or 105's, do you mean you are stacking them? Or do you just mean one each beam antenna? As then you talk about only one beam antenna????

In any case using a small light weight rotor may only work for a short time. This is because it will have to handle all the wind resistance of the a single beam antenna. How would a single rotor be able to move stacked beams?

Using a 15 foot "Practice" Tower is a good call. But you will want to also be able to easily access the beams tuning system to make adjustements. This is a big plus!

Adding in more weight, like steel pipe to reinforce Boom is a Bad Call. It will add siginificant weight to the antenna more uneeded stress on the rotor. Go with the factor Boom Truss Support Wire.

Guy wires should be used on all towers even stand along towers. The added support from guy wires in heavy winds is another real plus. You can use 3/8 Black UV resistance rope that will hold up and not interfere with the beam pattern.

Rotor rating for square feet, is valid only when the rotor is placed inside the tower cage assembly. And a Thrust Bearning is used at the top of the tower for the mast. If the rotor is installed as part of the mast, then the square foot rating is cut in half. So you want the rotor to be installed inside the tower. Makes sense.

Being a tight wad, sure we all like to save a few bucks. But building a tower with a large antenna on it is not the place to cut coners. During severe weather you want the tower and antenna to stay in place.

Suggest you look around and see other guys towers, and how there are installed. The ARRL Antenna Book has some good examples, and its at: http://www.arrl.org/catalog/8047/

Jay in the Mojave

http://www.a1antennas.com

 

[Master Chief]

It's not what you think! I'm thinkin of tryin to use one of these as a way to rotate a set of Maco 104's or 105's from
vertical to horizontal and vice-a-versa. If some of you old schoolers out there remember these rotors,they had the "mast thru mount" configuration.

The rotor in question is called the Alliance U-110, and I have some good news:
http://www.rotorservice.com/press3-alliance.htm

Now for the bad news:
Rotating a beam from horizontal (H) to vertical (V) (and vice versa) changes the SWR of the antenna due to effects from the ground. If you read any of the H/V antenna manuals you will see there are different gamma settings for H or V. Go ahead and try it anyway because experimenting is fine, but ye be warned!

Jay covered the rest!

 

[Slim]

No stacking Jay. Just one lone set of beams. Probably will just
stick w/the 104's anyways.I understand what you mean about the added weight of the steel pipe on the rotor too. Hadn't given that any thought either.

Very interesting link Master Chief! Thanks much!

"Rotating a beam from horizontal (H) to vertical (V) (and vice versa) changes the SWR of the antenna due to effects from the ground."

I hadn't even considered that Master Chief :shock: Thanks for
the wake-up call! I'll have to do some more research for sure.

What the hey,got all winter for that!!!!

I'll keep digging around and keep y'all posted on this project. Thanks for everyone's input. Great reading material at that also!
Slim CDX285

 

[Master Chief]

Just one lone set of beams.

Slim, "beams" is plural meaning more than one. This is where the confusion is. You are going to run a single BEAM. Correct?

 

[C W Morse]

I've had an old "clack" box rotor (Alliance) on a 11 element beam for about 8 years now. Still works. 8)

CWM

 

[Slim]

Slim, "beams" is plural meaning more than one. This is where the confusion is. You are going to run a single BEAM. Correct?

Yes you are correct sir. You're so right; I'm confusing the matter at hand aren't I? Just one 4-element beam. I don't think I'll pursue the 5-element.

I've had an old "clack" box rotor (Alliance) on a 11 element beam for about 8 years now. Still works.

That must be a small beam? 2mtr and or 70cm I'm guessing?
Even so,that's pretty darn good!

I like all the input here. It's getting fun and interesting!!!

Thanks again everyone.
Slim

 

[C W Morse]

I've had an old "clack" box rotor (Alliance) on a 11 element beam for about 8 years now. Still works.

That must be a small beam? 2mtr and or 70cm I'm guessing?
Even so,that's pretty darn good!

I like all the input here. It's getting fun and interesting!!!

Yep, mine is an 11 element 2 meter beam at 70 feet. Old clack box has held up pretty well--considering it cost me all of about 5 bucks!! 8)

73

CWM