With four guys the distance between any two 180 degree opposing guys will be 100' at
the base level. That is why I said that four guys at 45 degree angle at the top of a
50' mast will make a square at the four anchor points and that square at the base
level is 100' on each side. I am thinking that 30 degrees at the top might be fine for
my project in which case a smaller square.

Bill - K6TAJ


Jim Kelley wrote:

Dave Shrader wrote:

Only three guys are needed. Your 100 foot number may be in error.

100 feet would be the correct number if it was a two guy wire system.
Right? :-)

73, ac6xg

How about 75 feet between anchors in a three guy wire system?

zeno wrote:

Hi George,

A 45 degree angled guy from the top of a 50' tall mast will be out 50' from the
base of the mast. That would suggest that the "square" made from the four
anchor points is 100' on a side. I will have to look at the site and see if
that is possible.

Bill

Crazy George wrote:


Bill:

You need to enlist a little geometry and mechanical engineering. We like to
keep our top guys at 45 degrees or less (ground up to guy) where space
permits. The down force on the mast for each guy is then .707 of the guy
tension. As the guys get steeper, the down force on the mast becomes a
larger and larger portion of the total tension. So for a smaller
'footprint' with the guys near straight up, any side force on the guy from
wind or antenna tension becomes a larger down force on the mast. I need to
make drawings to clarify that point, so find someone mechanically inclined
to wave their hands and draw lines and make calculations for you.

As far as the stepladder on the roof, consider the average male is just
under 6' tall, with an 18" up reach. So he has to stand only 4 feet above
the mounting level of the base of the mast to erect it. A 5 foot stepladder
straddling the peak of most roofs is relatively stable if you are young,
limber and agile. Having the first (bottom) section SOLIDLY guyed is a
must. At least that's what I remember from the middle of the last century.

--
Crazy George
Remove N O and S P A M imbedded in return address
"zeno" wrote in message ...

Hi John,

For a 50' tall mast, what would you say would be the minimum acceptible

square

dimensions from vertices (on a flat plane with the base) of the guy wire

anchor

points?

Bill K6TAJ

John Moriarity wrote:


"zeno" wrote in message

...

How the heck did those TV crews of yesteryear erect 40+ foot
telescoping antenna masts sitting atop pointed roofs? Its not
exactly like you can set up a step ladder on such a roof to
get up the first 10 foot to pull up the rest of the sections.

That's exactly what we did! When you are
young and fearless and believe in your
personal immortality, it's amazing what
you can do ;-)

73, John - K6QQ

Bill, that's correct. But, most guying systems are only 3 wires on a 120
degree spread at 45 degrees from the anchor on the tower/mast. That
requires only 75 feet. A three wire system is a STABLE solution. A four
wire system is also a stable system.

BTW, I used to have a Rohn 25 system at 50 feet. Rohn recommended double
guying. First level at the 30 foot height. Second level just below the
rotator platform. Point I'm making is that one set of guys at the 50
foot level may not meet Zoning and Insurance safety requirements.

Deacon Dave, W1MCE

zeno wrote:

With four guys the distance between any two 180 degree opposing guys will be 100' at
the base level. That is why I said that four guys at 45 degree angle at the top of a
50' mast will make a square at the four anchor points and that square at the base
level is 100' on each side. I am thinking that 30 degrees at the top might be fine for
my project in which case a smaller square.

Bill - K6TAJ

Hi Dave,

Thanks for the info. I am recycling a 50' TV mast, and now that you mentioned the idea of
using 3 guy wires, it explains to me why the guy wire rings that came with this old mast
have an extra hole on one side (they give you a total of 5 holes). They were providing the
option for either 3 or 4 guy wires. On many roof peaks they just tied it to the corners of
the building thus using a 4 wire system. Since I will be putting this up in the middle of a
field for one of 5 masts to hold a 540' skywire loop, maybe I will just go ahead and use
three guy wires like you suggest since it is out in the middle of the orchard and not on a
four cornered roof.

In any case, I was previously in error when I said the side of the square at the base of a
4 guy wire 50' tall system was 100'. I meant that the diagonal of the square was 100',
making the sides of the square, as was suggested earlier in the thread by Crazy George, a
bit under 71' (100 divided by the square root of 2 which is 1.4142... or 100 times .707...

For the 3 wire guy system, I will just wing it and anchor the 3 guys in optimum position
considering the position of existing trees in the orchard.

Bill K6TAJ

Dave Shrader wrote:

Bill, that's correct. But, most guying systems are only 3 wires on a 120
degree spread at 45 degrees from the anchor on the tower/mast. That
requires only 75 feet. A three wire system is a STABLE solution. A four
wire system is also a stable system.

BTW, I used to have a Rohn 25 system at 50 feet. Rohn recommended double
guying. First level at the 30 foot height. Second level just below the
rotator platform. Point I'm making is that one set of guys at the 50
foot level may not meet Zoning and Insurance safety requirements.

Deacon Dave, W1MCE

zeno wrote:

With four guys the distance between any two 180 degree opposing guys will be 100' at
the base level. That is why I said that four guys at 45 degree angle at the top of a
50' mast will make a square at the four anchor points and that square at the base
level is 100' on each side. I am thinking that 30 degrees at the top might be fine for
my project in which case a smaller square.

Bill - K6TAJ