How high would you all feel comfortable about going with a Rohn 25G tower
without guys, with a 6-foot concrete base and a 2 meter / 440 gain
vertical antenna on top (e.g. Diamond X-700HNA)?

i have been on 50' of rohn 25 unguyed to take down a tribander. it was in a
no wind zone (surrounded by very dense 60'+ pine trees). i didn't like it
and would not recommend it. the 'old' book shows a max of 40' with 1.5sq ft
of antenn in a 70mph wind zone with no ice... and drops down to 20' with
90mph winds plus ice.

"Rick (W-A-one-R-K-T)" wrote in message
news

How high would you all feel comfortable about going with a Rohn 25G tower
without guys, with a 6-foot concrete base and a 2 meter / 440 gain
vertical antenna on top (e.g. Diamond X-700HNA)?

On Sun, 01 Jul 2007 14:07:54 +0000, Dave wrote:

i have been on 50' of rohn 25 unguyed to take down a tribander.

Wow. You're a better man than I am, Gunga Din. :-)

I actually wasn't planning on climbing it, rather planned on using one of
their hinge-over bases to raise and lower it when needed. I was thinking
of 40 feet, max.

To answer J's question... it's in a suburban setting on 2 acres of land,
and where the tower will be, if it fell over it would be all on my
property (i.e. no danger to neighbors or passersby). We're sufficiently
protected by trees such that only once in the 22 years I have lived here
have I seen winds of over about 40 MPH at below-the-treetops level (around
60-70 feet).

I have another Rohn 25G tower on the other end of the house that is
currently 40 feet, and I am in the process of adding another 10 feet for a
total of 50. It is guyed at the 30-foot level. I had to remove the top
section to add another 10-foot mid section, and now I'm in the process of
rasslin' the top section back into place (oh, so much fun). So, that'll
be 20 feet unguyed on top of 30 feet guyed. I'm trying to decide whether
I want to put a tribander on top of that or maybe get something light like
the Butternut Butterfly. I'm not a huge DX freak so don't really need a
full size multi-element 20-meter beam.

sorry, think again... no hinge bases allowed on free standing towers. those
are only for guyed or bracketed towers. free standing towers must embed the
base section in concrete.


"Rick (W-A-one-R-K-T)" wrote in message
news
On Sun, 01 Jul 2007 14:07:54 +0000, Dave wrote:

i have been on 50' of rohn 25 unguyed to take down a tribander.

Wow. You're a better man than I am, Gunga Din. :-)

I actually wasn't planning on climbing it, rather planned on using one of
their hinge-over bases to raise and lower it when needed. I was thinking
of 40 feet, max.

To answer J's question... it's in a suburban setting on 2 acres of land,
and where the tower will be, if it fell over it would be all on my
property (i.e. no danger to neighbors or passersby). We're sufficiently
protected by trees such that only once in the 22 years I have lived here
have I seen winds of over about 40 MPH at below-the-treetops level (around
60-70 feet).

I have another Rohn 25G tower on the other end of the house that is
currently 40 feet, and I am in the process of adding another 10 feet for a
total of 50. It is guyed at the 30-foot level. I had to remove the top
section to add another 10-foot mid section, and now I'm in the process of
rasslin' the top section back into place (oh, so much fun). So, that'll
be 20 feet unguyed on top of 30 feet guyed. I'm trying to decide whether
I want to put a tribander on top of that or maybe get something light like
the Butternut Butterfly. I'm not a huge DX freak so don't really need a
full size multi-element 20-meter beam.

On Sun, 01 Jul 2007 16:58:42 +0000, Dave wrote:

sorry, think again... no hinge bases allowed on free standing towers.

Hmmm ... OK, I guess I will have to be able to climb it...

I suppose I could install temporary guys while I'm up on it doing antenna
work, but in that location permanent guying wouldn't work too well...

free standing towers must embed the base section in concrete.

How about the BPC25G base plate (non-hinged)?

I already have a concrete base in place, 6 feet deep, intended for the
predecessor to the US Tower MA-series crank-up mast. The mast (and the
base, and the tower on the other end of the house) belonged to my father
when he lived with us, but he sold the mast many years ago, and the new
ones are a bit too pricey for me right now.

So, it's too late to embed the bottom section directly into the concrete,
at least in that location.

Dear Rick WA1RHT:

You have received useful advice.

While you may not have seen serious wind nor serious ice, eventually
Conn. will see same.

Two sections above guys next to the house is pushing prudence. With a
clear area next to the proposed tower in the back, three sections with just
a VHF antenna seems reasonable in view of your description.

It is nice to see questions from actual radio amateurs who state their
call-sign. What was your father's call-sign? Good luck.

73, Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Rick (W-A-one-R-K-T)" wrote in message
news
On Sun, 01 Jul 2007 16:58:42 +0000, Dave wrote:

sorry, think again... no hinge bases allowed on free standing towers.

Hmmm ... OK, I guess I will have to be able to climb it...

I suppose I could install temporary guys while I'm up on it doing antenna
work, but in that location permanent guying wouldn't work too well...

free standing towers must embed the base section in concrete.

How about the BPC25G base plate (non-hinged)?

I already have a concrete base in place, 6 feet deep, intended for the
predecessor to the US Tower MA-series crank-up mast. The mast (and the
base, and the tower on the other end of the house) belonged to my father
when he lived with us, but he sold the mast many years ago, and the new
ones are a bit too pricey for me right now.

So, it's too late to embed the bottom section directly into the concrete,
at least in that location.

to quote the book 'pinned bases must not be used'. think about it, when
there are no guys the highest stress point is where the metal meets the
concrete. each leg must be held down by something at least as strong as it
is. there might be a way to drill holes for each leg and epoxy in a stub of
some kind, but that would be a job for a pro.

"Rick (W-A-one-R-K-T)" wrote in message
news
On Sun, 01 Jul 2007 16:58:42 +0000, Dave wrote:

sorry, think again... no hinge bases allowed on free standing towers.

Hmmm ... OK, I guess I will have to be able to climb it...

I suppose I could install temporary guys while I'm up on it doing antenna
work, but in that location permanent guying wouldn't work too well...

free standing towers must embed the base section in concrete.

How about the BPC25G base plate (non-hinged)?

I already have a concrete base in place, 6 feet deep, intended for the
predecessor to the US Tower MA-series crank-up mast. The mast (and the
base, and the tower on the other end of the house) belonged to my father
when he lived with us, but he sold the mast many years ago, and the new
ones are a bit too pricey for me right now.

So, it's too late to embed the bottom section directly into the concrete,
at least in that location.

On Sun, 01 Jul 2007 15:20:54 -0400, "Rick (W-A-one-R-K-T)"
wrote:

On Sun, 01 Jul 2007 16:58:42 +0000, Dave wrote:

sorry, think again... no hinge bases allowed on free standing towers.

Hmmm ... OK, I guess I will have to be able to climb it...

I suppose I could install temporary guys while I'm up on it doing antenna
work, but in that location permanent guying wouldn't work too well...

free standing towers must embed the base section in concrete.

How about the BPC25G base plate (non-hinged)?

I already have a concrete base in place, 6 feet deep, intended for the
predecessor to the US Tower MA-series crank-up mast. The mast (and the
base, and the tower on the other end of the house) belonged to my father
when he lived with us, but he sold the mast many years ago, and the new
ones are a bit too pricey for me right now.

So, it's too late to embed the bottom section directly into the concrete,
at least in that location.
I have the early model Crank up mast (Wilson, CT-77) that I brought
with me from Ohio in 1993. No one would give me $400 for it! The top
section failed (overloaded with VHF-UHF stuff in 1980's while in a
guyed configuration. It twisted and developed a diagonal crease.

Some time in the late 1990's I restored the mast and built a home brew
base for it. With the top section removed it is about 55 feet.

I had an opportunity to examine a factory built erection base and I
felt too many compromises were made to keep it shippable. I was able
to acquire scrap steel from a local salvage yard. I mounted a 1/2"
steel plate (actually 2 1/4" pieces) about 20" x 30" on wide spread
1/2" J-Bolts embedded in 5 Yards of concrete (5 yards is overkill, but
that was the minimum charge so I elected to use it). I think they were
about 36" long. I feel the J-Bolts are the weakest part of the design.

I mounted an I-Beam vertically (about 12 feet tall) to the plate with
1/2" Grade 8 bolts and heavy angle iron to the base. I also mounted
the hinge plate for the mast to the plate. Then I fashioned a pulley
arrangement from the upright to raise & lower the tower.

The tower at the 23 foot mark with a Cushcraft A3S beam and a G800
Yaesu rotor is load enough to raise and lower. In that configuration a
ladder is still needed to reach the beam mounting bolts due to the
length of the antenna elements and the boom length.

The combination seems to handle the weather better at about the 45
foot mark so I seldom raise it above that.

I use an electric boat winch to raise & lower the mast extent ion. I
have been using a crank winch to raise & lower the tubular assembly.
Hopefully, I will get that converted to an electric winch sometime
this year. Age is catching up with me.

We have Hurricanes & Ice in North Carolina. However, the wind rarely
exceeds 80 mph in my area. I expect to lose the antenna some day but I
doubt the tower will fail.

Although I had an electric welder available I used nuts & bolts
because I felt my welding skills were suspect. I had a small back hoe
(Terra Mite) available for the digging & Heavy lifting.

I would do it again. But I would not consider it with a non
retractable mast.

John Ferrell W8CCW
"Life is easier if you learn to
plow around the stumps"

Dear Rick (WA1RKT):

It depends. Out where I live with nothing (such as trees and buildings)
to reduce the energy of the wind, I would not feel comfortable with more
than two sections of 25G. Three sections in an urban area with lots of
trees and buildings, and with no danger to life or property if the thing
blows down, might be reasonable.

The standard for such things (222G) adjusts the safety factor (though
not called that) depending on terrain and what is in the fall-over-radius.
Thus the information provided by Rohn provides only a starting point.

It depends. Tell us more.

73, Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Rick (W-A-one-R-K-T)" wrote in message
news

How high would you all feel comfortable about going with a Rohn 25G tower
without guys, with a 6-foot concrete base and a 2 meter / 440 gain
vertical antenna on top (e.g. Diamond X-700HNA)?

"Rick (W-A-one-R-K-T)" wrote in message
news

How high would you all feel comfortable about going with a Rohn 25G tower
without guys, with a 6-foot concrete base and a 2 meter / 440 gain
vertical antenna on top (e.g. Diamond X-700HNA)?


Probably not reccomended but a friend gave me one that had been up for 20
years that had an antenna package simliar(2m Ringo) to the one you mention
plus an HF tri-bander beam This antenna survived Hurricanne Hugo when
trees in the same yard didnt. Strange thing, we took the tribander down
first and the antenna swayed more after it was removed.

Jimmie