I have one last question.

I an using a home made tilt over mast made up of aluminium scaffold tube (
2" OD heavy duty) and the same tube for the stub mast. I have two heavy duty
brackets made up that clamp onto the scaffold tube to hold the rotator and
support bearing in place.

What would be a good average distance to have between the brackets that hold
the rotator and bearing?

Thanks



"Ralph Mowery" wrote in message
...

"Barrett" wrote in message
.uk...
I have two beams I want to install on the same mast. They are, Cushcraft
MA5B and an 9 element crossed Tonna.

What is the optimal distance that these antennas should be spaced?

What is the minimum distance apart can they be mounted before they have a
negative effect on each other?

Does it matter what beam is mounted on the top?

Does it make any difference how close the beams are mounted to the
rotator?

This is the first time that I have put any beams up, so I thought I
better get some good advice first.

Thanks


I don't think there is any real optimal distance within what most can put
us. I tried to look at what was needed vers what I could put up about a
year ago. I did see the url Ian listed. My requirements was to have
about 15 feet of mast out the top of the tower that is 57 feet out of the
ground.. At the top went a M2 432 beam, about 4 feet below that went a M2
2 meter beam both beams were on a 15 foot boom, and close to 5 feet under
that went a 5 element 6 meter beam on a 18 foot boom. Just over the top
of the tower was a 3 element triband for 20,15,and 10 meters. All
antennas are horizontal. I am sure this is nowhere near optimal but just
the best for what I had to work with.

"Barrett" wrote in message
o.uk...
I have one last question.

I an using a home made tilt over mast made up of aluminium scaffold tube
( 2" OD heavy duty) and the same tube for the stub mast. I have two heavy
duty brackets made up that clamp onto the scaffold tube to hold the
rotator and support bearing in place.

What would be a good average distance to have between the brackets that
hold the rotator and bearing?

Thanks

I don't have any idea. I just put my rotator mounting plate where it fit
the bracing in the tower. That put about 5 or 6 feet of a 21 foot piece of
2 inch OD ( 1 1/2 trade size of galvinised pipe. I just based that on
where the plate fit and having enough pipe in the tower were I can pull the
rotator out if it needs repair.

Ralph, was the 21 foot tube you used steel or alloy?


"Ralph Mowery" wrote in message
...

"Barrett" wrote in message
o.uk...
I have one last question.

I an using a home made tilt over mast made up of aluminium scaffold tube
( 2" OD heavy duty) and the same tube for the stub mast. I have two heavy
duty brackets made up that clamp onto the scaffold tube to hold the
rotator and support bearing in place.

What would be a good average distance to have between the brackets that
hold the rotator and bearing?

Thanks

I don't have any idea. I just put my rotator mounting plate where it fit
the bracing in the tower. That put about 5 or 6 feet of a 21 foot piece
of 2 inch OD ( 1 1/2 trade size of galvinised pipe. I just based that on
where the plate fit and having enough pipe in the tower were I can pull
the rotator out if it needs repair.

"Barrett" wrote in message
.uk...
Ralph, was the 21 foot tube you used steel or alloy?


I don't know what kind of pipe it is. I went to a place that sells metal
and told them I wanted some galvinised pipe. One piece 1 1/2 inch trade
size about 20 feet long and also to support the tower I got 3 pieces that
are about 3 or 4 inches in diameter and 9 feet long. Those were for the guy
wires. I put around 4 feet of the pipes in the ground and filled them with
cement. Hopefully that will keep them from bending over. The tower is
guyed around 30 feet and again near the top. It is also in a yard of
cement. More or less to Rhon's specs for a 25G tower. I bought the tower
sections used. Think it was the least expensive part of the whole thing..

Here are a few pix of the tower.

http://home.earthlink.net/~ku4pt/images/

Ralph Mowery wrote:

Barrett wrote:
Ralph, was the 21 foot tube you used steel or alloy?


I don't know what kind of pipe it is. I went to a place that sells metal
and told them I wanted some galvinised pipe. One piece 1 1/2 inch trade
size about 20 feet long and also to support the tower I got 3 pieces that
are about 3 or 4 inches in diameter and 9 feet long. Those were for the
guy
wires. I put around 4 feet of the pipes in the ground and filled them
with
cement. Hopefully that will keep them from bending over. The tower is
guyed around 30 feet and again near the top. It is also in a yard of
cement. More or less to Rhon's specs for a 25G tower. I bought the
tower
sections used. Think it was the least expensive part of the whole thing..

Here are a few pix of the tower.

http://home.earthlink.net/~ku4pt/images/


Pipe is supplied in various "schedule" sizes, starting at 10. Common iron
plumbing pipe is malleable (low carbon steel) and usually Schedule 40. So,
what are the actual dimensions? Try he
http://www.engineersedge.com/pipe_schedules.htm. So, commonly available
1-1/2" (1.90" OD) Schedule 40 would have a 0.145" wall thickness.
Bryan WA7PRC

"Bryan" wrote in message Pipe is
supplied in various "schedule" sizes, starting at 10. Common iron
plumbing pipe is malleable (low carbon steel) and usually Schedule 40.
So,
what are the actual dimensions? Try he
http://www.engineersedge.com/pipe_schedules.htm. So, commonly available
1-1/2" (1.90" OD) Schedule 40 would have a 0.145" wall thickness.
Bryan WA7PRC


It is Schedule 40 pipe..This is not the best pipe to use, but should be
strong enough for me. The tribander is just over the top of the tower and I
doubt the other antennas will have much wind load. I live in the middle
of North Carolina so we do not usually get much ice or very high winds.

Ok, on all the info. I will do some experiments and find out what works best
in this location.

Thanks all


"Ralph Mowery" wrote in message
...

"Bryan" wrote in message Pipe is
supplied in various "schedule" sizes, starting at 10. Common iron
plumbing pipe is malleable (low carbon steel) and usually Schedule 40.
So,
what are the actual dimensions? Try he
http://www.engineersedge.com/pipe_schedules.htm. So, commonly available
1-1/2" (1.90" OD) Schedule 40 would have a 0.145" wall thickness.
Bryan WA7PRC


It is Schedule 40 pipe..This is not the best pipe to use, but should be
strong enough for me. The tribander is just over the top of the tower and
I doubt the other antennas will have much wind load. I live in the
middle of North Carolina so we do not usually get much ice or very high
winds.