Silly question for the seriously minded genius types

[Ferrarimx5]

Suppose you only have a base station and would like to maximize your antenna power.
Suppose you only had access to six complete sets, unopened packs of Over the road truckers (18 wheelers) phased 48" 7/8 wave Mirror Mount antenna kits (enough to set up six, 18 wheelers with dual antennas).

Suppose you had access to a very large, flat lot and could mount the antennas 30 feet into the air.

Note: I just happen to have 6 sets (From the 70's) that are still in the packages.
Is there a design that anyone could come up with to make these into a beam?
What would you do, with one or more of the sets if your only consideration was to use them for your base station?

Are they worthless? Or is it worth experimenting with?

Each kit has (2) 48" 7/8 Wave, Golden Jammer Power Anetnnas, 1000 watt rated

(2) 3-way Mirror Mount with SO-239 Connectors

(1) RG-58U Co-Phase Cable for Plug to Plug connections

Each kit is Made in America
Designed and built for the Professional Truck Driver and sold for $65.90 back in 1975..

Just thinking, perhaps there is an application..
Just moving stuff that was in one of my Storage sheds and thought of several ways to make them serviceable and perhaps quite directional. Might be fun just messing with the local bad acting CB'ers that are only a few miles from me , but mostly just thinking about how they might be able to work as part of a serviceable beam .

Or just see what comments would come out of the playful idea of salvaging some NOS that ihas been wasting away on a shelf.

 

[Robb]

No genius necessary to answer this; just understand how a beam antenna or vertical array works.

You don't have to spend that much money to get the same effect. You could use 2 or more 10 ft lengths of EMT conduit and do a better job.

A vertical array works like this:

1) All you would have to do is change the lengths of each conduit from a resonant length for a given freq (eg: a 1/4 wavelength of 27mhz is approximately ~9 ft).
2) The distance between each vertical would be important.
3) The direction of max gain would be defined by which direction they were arranged, and the length of each one would need to be decreased by approximately 5% from the tallest vertical - which is also the powered radiator.
4) You only need to power one element; not all of them.


But a beam antenna is better, because you can turn it with a rotor, and you can change its polarity from vertical to horizontal. Much neater package - too.

If you take some time to understand antennas and how they work; then you would be able to answer most of your own questions. Plenty of solid sources on the the net. You will need to understand what makes any antenna 'resonant'. But first you will need to understand what the relationship between wavelength/frequency is.

 

[Ferrarimx5]

Robb, thank you for your input.

Hmm, I've hand built a few antennas and set up a few towers:
Some of the projects included (J-Pole) 2 meter, 440. Several different types of TV antennas. Dual Long Wire, Shortwave antennas for a switchable North South and East West reception (Okay, technically not a difficult set of antenna to design and isolate). Scanner antennas.

Some designs were out of copper tubing, some out of aluminum.

I've tried phasing two Antron 99's and had limited success/failure.

Always built from a proven design and sometimes through a discussion, round table, think tank.

May phase a couple sets of the "Trucker Antennas" on the roof of my house positioning them 1/2 a wave apart, just to squirt a signal north-south and changing that to east-west with a flip of a switch.

Adjusting each pair of antennas for a beam would be a pain, but was hoping for some creative ideas on how to possibly add extensions to each element so they could be set up and tuned for 12 meter, 15 meter or even 17 meter. Not asking anyone to design the antenna array, just getting some suggestions so that I do not end up storing them for another couple of decades, or robbing parts to use on other projects.

I also have a Yaesu FT-857D with a tar heel 400a screwdriver but this discussion is more about gathering ideas to turn a few kits on a shelf into useful decorations for the back yard.

Ultimately you are correct, I can simply do this myself with little or no input, but thought it might turn into an interesting discussion reqardless of the outcome.

 

[StrangeBrew]

The four square array always had me curious, seems like quite a project getting one up and running though.

 

[DainBramage]

...) The direction of max gain would be defined by which direction they were arranged,....

Actually Robb, the radiation pattern can be changed from a figure 8 to a cartiod pattern by feeding them in or out of phase.

 

[Captain Kilowatt]

The four square array always had me curious, seems like quite a project getting one up and running though.

I have a friend that is just laying radials for his 40m four square. It should be awesome when completed. I worked ZS6CCY in South Africa on his 80m four square and it worked like a charm.

Speaking of radials I cannot image the radial field required for what the OP proposes with the short mobile antennas.

 

[RatsoW8]

Those six sets of dual trucker antennae are now vintage and rare- plus having been made in the 70's will talk farther that any similar antenna made today. They may even increase one's "loudness" if you get my drift. Sell those puppies on eBay and use the proceeds to buy yourself a good tri-band Yagi and rotator..

 

[StrangeBrew]

....
Speaking of radials I cannot image the radial field required for what the OP proposes with the short mobile antennas.

He just needs to get a bunch of truck mirrors. I'm thinking a tower or pole with four truck mirrors on extra long brackets mounted so that they form an X when viewed from the top, mount up his mobile antennas and he'll be set.

On a more serious note is there any reason a four square type arrangement wouldn't work with vertical dipoles? on 40/80m multiple vertical dipoles would be less than practical to build but with the antennas he's using it opens up some possibilities.

 

[Riverman]

You can always fashion a ground plane using five of the antennas (one as the vertical and four as the radials (sloped downward at 45 degrees).

I made one with only two radials and it worked fine despite only being 15' in the air. Two additional radials and an extra 15' of height should show a marked improvement.

 

[Captain Kilowatt]

He just needs to get a bunch of truck mirrors. I'm thinking a tower or pole with four truck mirrors on extra long brackets mounted so that they form an X when viewed from the top, mount up his mobile antennas and he'll be set.

On a more serious note is there any reason a four square type arrangement wouldn't work with vertical dipoles? on 40/80m multiple vertical dipoles would be less than practical to build but with the antennas he's using it opens up some possibilities.

Any type of vertical antenna can be used in a fourquare array. it is simply the spacing and phasing that needs to be done correctly. usually the antenna used is a ground mounted 1/4 wave vertical with a radial ground plane. Dipoles for 40 or 80m would be rather tall to erect especially for 80m but would eliminate the requirement for radials.

 

[Captain Kilowatt]

You can always fashion a ground plane using five of the antennas (one as the vertical and four as the radials (sloped downward at 45 degrees).

I made one with only two radials and it worked fine despite only being 15' in the air. Two additional radials and an extra 15' of height should show a marked improvement.

And a REAL base antenna would show even more of an improvement especially a directional beam if he is looking for something with a pattern other than omnidirectional.

 

[Riverman]

And a REAL base antenna would show even more of an improvement especially a directional beam if he is looking for something with a pattern other than omnidirectional.

Can't argue with that.
Just suggesting something he could do for fun with his trucker antennas.

 

[Tallman]

You could make a YAGI type of antenna. Set the reflector elements to resonate at the highest plus some end of your frequency, driven element at the center, and the director at the low end of the frequency. I built one like that for my home and it worked pretty well for about 10 days and the a high wind from a Thunder Storm flattened my radio shack and the tower as well. I was working on changing the spacing and tuning to get the best front to back ratio and best receive gain.

 

[2FB327]

Strangebrew, couldn't he mount all of them on his car with chicken lights and go down to the rest area and "mess with them truckers"?

 

[StrangeBrew]

Strangebrew, couldn't he mount all of them on his car with chicken lights and go down to the rest area and "mess with them truckers"?

I would imagine that if he bought a crew cab pickup and put west coast style mirrors on all four doors he may be able to make a mobile four square work.



Another idea for a base antenna would be a Lazy H.