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would this work as an antenna tower? Pros & cons


WRPQ991

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Wow!  That's actually really neat... but I personally wouldn't spend that much. 

The platform is only 17' high.  The shooting rail is the part that is at 20', and the rail doesn't look like it would hold much weight.  You will almost double your range on flat terrain, but we are talking about going from 3.1 miles to 5.9 miles.

I bought this instead....

https://mfjenterprises.com/products/mfj-1906h?_pos=25&_sid=bfd1eb1e0&_ss=r

I get about a 9 to 10 mile radius (in flat/level terrain) with my antenna on this.  A tripod, ground stakes and guy lines, I spent less than $280.   I designed it to be portable, but it can be a permanent setup with zero concerns...  in fact, right now and for the past 3-4 months, it's actually behind my house in the woods being used to hold up my 80 meter HF antenna.

 

Pot_2m-440_Repeater_Antenna_2.thumb.jpg.d46af1bc3c9a3f1dd419153667f1e5e6.jpg

Pot_2m-440_Repeater_Antenna_3.thumb.jpg.248cce85141f0e2a6445384797198b4e.jpg

 

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8 hours ago, marcspaz said:

Wow!  That's actually really neat... but I personally wouldn't spend that much. 

The platform is only 17' high.  The shooting rail is the part that is at 20', and the rail doesn't look like it would hold much weight.  You will almost double your range on flat terrain, but we are talking about going from 3.1 miles to 5.9 miles.

I bought this instead....

https://mfjenterprises.com/products/mfj-1906h?_pos=25&_sid=bfd1eb1e0&_ss=r

I get about a 9 to 10 mile radius (in flat/level terrain) with my antenna on this.  A tripod, ground stakes and guy lines, I spent less than $280.   I designed it to be portable, but it can be a permanent setup with zero concerns...  in fact, right now and for the past 3-4 months, it's actually behind my house in the woods being used to hold up my 80 meter HF antenna.

How flexible/rigid does that top section seem, Marc?  I bought a 40 foot Spiderbeam, which is great for portability, but the top section is so flexible that I would hesitate to use it for anything other than holding up a wire antenna.  To support a small vertical antenna and keep it vertical, I would probably leave the top section telescoped down inside the next section.

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2 hours ago, Sshannon said:

How flexible/rigid does that top section seem, Marc?  I bought a 40 foot Spiderbeam, which is great for portability, but the top section is so flexible that I would hesitate to use it for anything other than holding up a wire antenna.  To support a small vertical antenna and keep it vertical, I would probably leave the top section telescoped down inside the next section.

 

If you just stick it in a tripod and don't use guys, in low/zero wind it will hold about 5 lbs max at full extension.  It will not hold much weight at all.  In fact, I was up on Flagpole Knob when some 40 mph winds came through and damn near folded it in half.

Now, if its guyed with a good tripod, It will easily hold 25-30 lbs.  I use 3 tiers of guys with one set at the top 5 inches.  The guys keep the mast straight under the load for max weight capacity.  I have had my 10' vertical in 80-90 mph winds.  The top of the antenna was moving all over, the the mast didn't budge. 

The two heaviest loads I have run while fully extended is (1.) a mono-band 20m hex beam with thrust bearings and a rotor at the base, and (2.) a 10' tall 2m repeater antenna, 20m dipole and an 80m inverted V with a balun and choke.  That second setup was in a massive overnight snow storm we had during Winter Field Day a few years ago.

 

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That's a nice pole, but with the guy wires has a pretty big footprint. Do you encounter any issues with no ground plane, except the ground of course. While the hunting tower has the expanded metal..Here, where I am, the ground has very little reflective properties. Mostly limestone and sand. I see people using aluminum pipe from the top of a wire fence, or a few sticks of PVC, and all sorts of redneck engineering. For your heavy rotor and a set of moon rakers, you could remove the seat and use the pedestal.

I'm just kicking around ideas right now.

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I actually use a wide footprint to tolerate high winds.  You can bring them in and reduce the footprint, but it will reduce total tolerated wind speeds.  There is some math that can be done to find the critical angle if you want to go that route. 

 

I don't have any issues with a ground plane.  All of my vertical antennas have built-in ground planes in the mount or are half wave antennas that don't need a ground plane.  So, the actual ground quality doesn't matter.  It does play in if you try to use a dipole for HF, though. 

 

I have seen some creative engineering... and I aways ask "if it works, was it really a bad idea?" LOL 

 

Yeah, I was thinking pulling the seat and putting a short mast (5', maybe) and rotor would be good. Not to mention you can climb up there to work on it easily, which is awesome. 

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