tripods and antenna mounting

[mr_fx]

Yesterday I finished modifying a pair of Rohn TRT60 5 ft tripods to be a little stronger and to accept a Ham IV rotor

I need to decide how to mount the antennas...

I have the following antennas:

- Wilson SY-33 3 element tri band (a little over 5 sq ft )

- 11 element 2 meter yagi (1.25 sq ft)

- 28 element 70cm yagi (1.6 sq ft)

- 2 element 6 meter aluminum moxon (apprx 0.75 sq ft)

- 8ft tall fiber glass 2m / 440 colinear vertical







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[mr_fx]

I am also considering guy wires

the masts are aluminum

all parts are welded to the tripod, and the joints are welded as well

 

[wavrider]

Largest antenna on bottom smallest antenna on the top

 

[n8fgb]

That thing will never support the weight of those antennas. You need a hole for the 8 wire cable. Those arms will not hold the weight. The wind load will twist it li a pretzel. Start looking use Rohn 25.
Rich

 

[Captain Kilowatt]

Watch out for that rotator binding. Those rotators will not rotate concentrically unless the mast size is 2" O.D. unless it is shimmed. I ran one for 30 years. It only has one moveable plate. The Yaesu rotators have two moveable plates that allow for concentric rotation regardless of mast diameter. I use one of those as well now.

 

[mr_fx]

Watch out for that rotator binding.

I took that into acct while modding these I made sure everything could rotate smoothly before I started to weld everything in place

 

[mr_fx]

added the wind loads for the antennas to the OP

I am thinking that ti pod A should have only the 3 element HF tribander (about 5 sq ft)

while tripod B should have,

top - 6 meter 2 element moxon (about 0.75 sq ft)

MIDDLE - 70CM 28 element (1.6 sq ft)

Bottom - 2m 11 element (1.25 sq FT)

 

[mr_fx]

rohn's manual states to use guy wire IF the antenna wind load exceeds 2 square feet and/or is mounted for than 10 feet above the mast

 

[Captain Kilowatt]

I took that into acct while modding these I made sure everything could rotate smoothly before I started to weld everything in place

So you actually had the rotator operating to turn things before you welded things in place and you took the off-center rotation into account? Still not sure how that would work out because the entire mast will not rotate in a perfect circle unless the mast is the proper size. It will still rotate off center. The only way to account for it would be to shim the base of the mast to make it the proper size or leave LOTS of slack in any bearing or sleeve above it. Lots of slack.

 

[Marconi]

I don't recommend mounting antennas on your roof and for sure no guying.

The antennas I've had on my roof worked fine, but I paid for it big time in roof damages in the long run, and that ain't cheap repairs.

Note: I won't attach anything to my house anymore.