Homemade Antennae Mast?
Dennis
Any tips for making a 50 or so antennae mast from scratch? Maybe
something with PVC?
Thanks,
Dennis
John P. Franklin
antennas, it will also support dipoles and such. Get the chain-link fence
top rail it's about 1 1/2 inch in diameter and the ends are swaged. Each one
is 10 and a half feet long and much more inexpensive than "masting". They
are quite strong since they are made for fences.
Have fun........
Pat
John Lehman
Perhaps you should consider using EMT. Commonly used in electrical
wiring systems in residential and commercial buildings. It's cheap and
can be welded easily. It would make a dandy tower. Good Luck!
Brad Dyson
Dennis <den...@nospam.net> wrote in message
news:mXx+OL57Jus4fY...@4ax.com...
> Hi folks,
>
> Any tips for making a 50 or so antennae mast from scratch? Maybe
> something with PVC?
>
> Thanks,
>
> Dennis
Dennis,
I used to have a couple of old QST handbooks that showed how one could
make 30 ft antenna masts from wood, and in one example a guy built a mast
out of 3 in rain gutter! ( he put it on a mount that allowed him to 'tilt'
it down for repair, modifications, etc) Most all of these had to be guyed,
however... I think that most any 60s or 70s QST Handbook should be able to
give you some good ideas...
Norm, n4...@prodigy.net
Dennis
wrote:
>Hey Dennis,
>Perhaps you should consider using EMT. Commonly used in electrical
>wiring systems in residential and commercial buildings. It's cheap and
>can be welded easily. It would make a dandy tower. Good Luck!
Yes, I thought about that, and I can weld, but I'm no engineer. I
build things and when they break I build 'em stronger. I was hoping to
only due this project once. <grin>
My thoughts on the EMT would be the same as the PVC, starting with 5
or 6 inch and tapering 1 inch per length with one set of guy wires at
the top. But I have little idea if that would hold up in 60-70 mph
wind gusts.
If I could see a similar unit I could probably build something like
it.
Thanks!
Dennis
chain link, too. Stronger than 1.25 TV mast and longer lasting as
well. But, I want to go 50 up. How many sets of guy wires would I
need? I spent some time searching the internet and didn't find much
on antennae masts. Maybe one good book would have all I need.
Thanks for the idea.
Dennis
John H. Carver Jr.
Gary Coffman
>Yes, yes, you're right. I had forgotten about that. I've put up some
>chain link, too. Stronger than 1.25 TV mast and longer lasting as
>well. But, I want to go 50 up. How many sets of guy wires would I
>need? I spent some time searching the internet and didn't find much
>on antennae masts. Maybe one good book would have all I need.
Using fence rail, 3 sets of guys should be fine to 50 feet with a reasonable
antenna wind load on top.
The mast design depends on how much loading you're going to put
on it. The more wind load you have, the more you have to crank on the
guys to keep it up, and that increases the compression load on the
mast, which means it needs more guying to prevent buckling, and
needs to be stronger to tolerate the compression load.
BTW, PVC is totally unsuitable as a mast. It doesn't have a lot
of compression strength, it buckles easily, and it is vulnerable
to UV damage.
Gary
Gary Coffman KE4ZV | You make it |mail to ke...@bellsouth.net
534 Shannon Way | We break it |
Lawrenceville, GA | Guaranteed |
Steve Beyers
Dennis wrote:
> On Fri, 14 Jan 2000 02:38:39 GMT, John Lehman <jole...@napanet.net>
> wrote:
>
> >Hey Dennis,
> >Perhaps you should consider using EMT. Commonly used in electrical
> >wiring systems in residential and commercial buildings. It's cheap and
> >can be welded easily. It would make a dandy tower. Good Luck!
>
> >
EMT is great stuff for making all kinds of things, including antennas. But
be careful when welding it. The fumes can mess up your lungs in short
order. Be sure you have some positive way to keep them away from your face.
Dennis
when welded.
Thanks
Dennis
pair of guys going to the edge of the roof with a 10ft 3/4 inch emt
angled from mast to ridge. As the mast goes higher, and if I need 3
sets of guys, that 3/4 inch will have to become 1" and then 1.25 for
the second and third support. All so I can get local PBS stations....
So your no found of PVC? I didn't think about the UV. Paint might
take care of that though, and silver would look better anyway. But I
would have thought that 5 or 6 inch would have been fine otherwise.
But if chain link rail will get me to 50 ft, I rather have it.
Thanks again,
Dennis
On Fri, 14 Jan 2000 21:05:29 -0500, Gary Coffman <ke...@bellsouth.net>
wrote:
>On Fri, 14 Jan 2000 17:40:29 -0600, Dennis <den...@nospam.net> wrote:
Dennis
around here somewhere. I bet they have something in there. I'll keep
an eye out for some QST as well.
Thanks!
On Fri, 14 Jan 2000 15:00:24 -0500, "Brad Dyson" <n4...@prodigy.net>
wrote:
>
>
>Dennis <den...@nospam.net> wrote in message
>news:mXx+OL57Jus4fY...@4ax.com...
>> Hi folks,
>>
>> Any tips for making a 50 or so antennae mast from scratch? Maybe
>> something with PVC?
>>
>> Thanks,
>>
>> Dennis
>
Mark Keith
>
> Thanks for the info. My current TV mast is on an eve. I now have
> pair of guys going to the edge of the roof with a 10ft 3/4 inch emt
> angled from mast to ridge. As the mast goes higher, and if I need 3
> sets of guys, that 3/4 inch will have to become 1" and then 1.25 for
> the second and third support. All so I can get local PBS stations....
>
> So your no found of PVC? I didn't think about the UV. Paint might
> take care of that though, and silver would look better anyway. But I
> would have thought that 5 or 6 inch would have been fine otherwise.
>
> But if chain link rail will get me to 50 ft, I rather have it.
>
> Thanks again,
>
> Dennis
It will get you there (50ft), but will it be easy to put up. I bet not.
I also use the fence posts quite a bit, and they work nice, but going to
50 ft, will be a trick to get up unless you have help. The main problem
being they are 10 ft tall. I can raise two of them (20ft) all by myself,
no problems. But not 30 ft without help.Just too top heavy. 50
ft???Whoooa doggies...If you want to go 50 ft, I'd go with a pushup
mast. Much, much easier to raise. Rat shack makes a 36 ft version, or
you could get a rohn at 50-70 ft. For a lower mast the fence sections
are great. Cheap too. 5 bucks a pop around the corner at home depot. But
for higher than 20 ft, better call for help. You might could get 30 ft
up by yourself, if you are a strong, and have the guys strung out to
tighten as you raise, but even that will be kinda tricky. MK
--
http://web.wt.net/~nm5k
Dennis
put the base next to the house and stand it up to reach the eves and
then attach it loosely. Then push it up. That's how we do the 30ft
1.25 mast now. (But I can't extend all 30 foot above the roof line,
too flimsy!) If I ground mount next to the eve, then I need 50 ft.,
but I can pull the mast up to the eve with a pulley and tractor.
Sure would be nice to be able to lower it to the ground for service!
I noticed a tapered mast that ChannelMaster makes, up to 30 or more
feet, but I have no idea what it looks like or how it works. Would
that be a "pushup"?
Thanks!
Dennis
Mark Keith
>
> If I eve mount only, then 30 ft. would be enough (I hope!). I would
> put the base next to the house and stand it up to reach the eves and
> then attach it loosely. Then push it up. That's how we do the 30ft
> 1.25 mast now. (But I can't extend all 30 foot above the roof line,
> too flimsy!) If I ground mount next to the eve, then I need 50 ft.,
> but I can pull the mast up to the eve with a pulley and tractor.
>
> Sure would be nice to be able to lower it to the ground for service!
>
> I noticed a tapered mast that ChannelMaster makes, up to 30 or more
> feet, but I have no idea what it looks like or how it works. Would
> that be a "pushup"?
>
> Thanks!
>
> Dennis
Should be. Would be much easier than solid mast sections. I use a push
up for my normal dipoles etc. I use the rat shack 36 ft model with an
extra section I added for about 40 ft. MK
--
http://web.wt.net/~nm5k
dm
experimented a lot with PVC masts. I currently have two 60 footers up, for
use with wire antennas. Two halyards each. I have a 17 meter loop hanging
on one mast, and on the other, and the high lead between, I am hanging a
very effective three element 30 meter Yagi. PVC with Nylon guys seems to be
completely inert on HF.
A friend here uses two masts , 70 feet up, for top loaded low band
verticals...the vertical wire pulled up right alongside the mast...since it
has no effect on the antenna.
If you choose to go NON-metal, and are interested, let me know and I'll be
glad to keep you from re-inventing the wheel!!! VY 73 "DM"
Dennis wrote in message ...
Dennis
Dennis
Yes! Very interested!
Thanks,
Dennis
KG4FET
If you do end up using the fence top rail it is easier to set it up leaning
against the house and walk it up from there. Screw the swags togther and they
wont give as you pull it up. It does take atleast 2 people to do this but it
is easier then to try to walk it up from the ground. If the antenna is heavy
it will buckle. I would use atleast use one set of guys per 10 feet above the
highest solid support (ie...The side of the house). Top rail is cheap , $3.45
per 10ft here at Home Depot, and as good or better then rat shaks antenna mast.
Good Luck
Sandor KG4FET
Dennis
up with a cable. I can see needing guys every 10 ft or so when it's
under wind load, but what about just erecting it? If I have 50-60 ft
mast/BIG TV antennae/rotor on the ground and fasten a cable halfway up
and then to a pulley at the roof peak and back down to a small tractor
(or me three teenagers) could we pull it up? And without it buckling!
Thanks,
Dennis
Gary Coffman
>Sure would be nice to be able to hinge it at ground level and pull it
>up with a cable. I can see needing guys every 10 ft or so when it's
>under wind load, but what about just erecting it? If I have 50-60 ft
>mast/BIG TV antennae/rotor on the ground and fasten a cable halfway up
>and then to a pulley at the roof peak and back down to a small tractor
>(or me three teenagers) could we pull it up? And without it buckling!
No, it would buckle. You can't even reliably do that with 50 feet of Rohn 25.
The rail is strong in compression, but it will bend pretty easily against
lateral forces, and the moment arm created by tilting it up will generate
a lot of lateral force.
The best way to erect this sort of structure is to stack it in place. That's
the way we'd erect a tower. The only forces would then be compressive,
and the mast can stand that easily. But if that's not practical in this case,
then you want to stack it as nearly vertical as you can and use lots of
temporary guying to prevent buckling as you raise it into position. Once
it is vertical, you don't need so many guys since the loading is primarily
compressive.
wb
Looking at the prices of towers i think i could do a lot better, anybody
copied a US Towers 89 or 100 footer? I have estimated the material cost, not
including labour i could do a lot better by doing it myself. No i am not
worried about it falling down on acres of land!! Any hints or tips?
Will
Dennis <den...@nospam.net> wrote in message
news:LA+JOJbG+bxQcl...@4ax.com...
> Sure would be nice to be able to hinge it at ground level and pull it
> up with a cable. I can see needing guys every 10 ft or so when it's
> under wind load, but what about just erecting it? If I have 50-60 ft
> mast/BIG TV antennae/rotor on the ground and fasten a cable halfway up
> and then to a pulley at the roof peak and back down to a small tractor
> (or me three teenagers) could we pull it up? And without it buckling!
>
Yuri Blanarovich
>I would like to build my own crankup tower, anybody built their own?
Based on my experience with putting up Big Bertha, this must be the nicest and
least labor intensive solution to ham radio tower. Bertha is basically
telescoped down steel pole made of steel pipe. It is self supporting, has
claiming steps, very easy for one person to install and maintain antennas, you
can stack antennas from the top to bottom.
Construction involves various diameters pipe nested and welded together. The
whole tower rotates in the ground sleeve. It is strong, sleek and even best
looking tower/mast. Telrex used to make them, but number of them were home
brewed (W0SYK) to 120 ft height.
Check some pictures in old CQ mags
http://members.aol.com/ve3bmv/Razors.htm
that was 110 ft Bertha with 62 ft Razor beams (Quad-Yagi combo).
(14" diameter at the bottom, tapering to 2.75" at the top, sitting in 18" OD
.5" wall sleeve)
Yuri, K3BU, VE3BMV
Richard Harrison
"No, it would buckle. You cant even reliably do that with 50 feet of
Rohn 25."
Gary is right, but there`s a way to raise flimsy towers intact. You
should not try it at home without experienced direction and lots of
help.
It requires (2) stout poles, wooden or whatever, that are strong enough
to be uprighted by pivoting on one end.
One pole is almost as long as the tower to be uprighted. The other pole
is a little over 1/2 the length of the tower to be uprighted. The
shorter pole is equipped with a snatch block at the end to be elevated.
The longer pole is lashed to the tower at several points.
The shorter pole is erected with manpower and guyed off. The longer pole
is snatched in the middle and hoisted aloft. Using a tag line attached
to the lower end of the tower, it is hauled down and positioned on the
tower base.
The already attached guy wires are connected to their pre-positioned
anchors.
Using this method, a trained Radio Free Europe tower crew could erect
(4) flimsy Wind Turbine towers and hang a Signal Corps rhombic kit in
one day. More time was required to prepare the anchors and to construct
transmission and dissipation lines. But, the tower erection was much
more efficient than stacking section after section in the air.
I want to thank my Portuguese friends who have long been excellent
riggers and sailors for this winning idea.
Best regards, Richard Harrison, KB5WZI
Richard Harrison
"I would like to build my own crankup tower, anybody built their own?"
Not a crankup, but 7 guyed towers that had to withstand near hurricane
force winds nearly every day in Tierra Del Fuego.
Don`t do it unless you have to. It is not economical. It requires
expertise. There are no guarantees.
My situation was dire. I had to make towers if I were to end my work on
time and go home.
We had material, machinery, manpower, steel strength tables, and I was
educated. We also had an expert machinist/welder named Nikita who had
escaped the Soviet Union and was raring to go.
I whipped out my sliderule and we did it. The towers stood the test and
are likely still standing. We had no way to galvanize the towers, but
the climate is so cold that uncoated steel rusts very little. We painted
the towers anyway, international orange and white.
But, if you`re not backed against the wall, it doesn`t make sense to
make your own towers.
CASH MONEY
MANY PEOPLE I WOULD NEED TO ERECT THIS FOR MY SON TO TALK ON 11 METERS I
AM ASKING FELLOW HAMS CAUSE CB PEOPLE GIVE CRAZY ANSWERS.EMAIL ME WITH
THIS INFO THANKS!
Dennis
that I've read or seen pictures of towers that tilt up and down.
Thanks,
Dennis
On Fri, 21 Jan 2000 23:07:46 -0500, Gary Coffman <ke...@bellsouth.net>
wrote:
>On Fri, 21 Jan 2000 21:08:20 -0500, Dennis <den...@nospam.net> wrote:
>>Sure would be nice to be able to hinge it at ground level and pull it
>>up with a cable. I can see needing guys every 10 ft or so when it's
>>under wind load, but what about just erecting it? If I have 50-60 ft
>>mast/BIG TV antennae/rotor on the ground and fasten a cable halfway up
>>and then to a pulley at the roof peak and back down to a small tractor
>>(or me three teenagers) could we pull it up? And without it buckling!
>
Dennis
have an easily raised AND lowered for service 50 ft tower...
Thanks for the tips though,
Dennis
On Sat, 22 Jan 2000 09:12:47 -0600 (CST), richard...@webtv.net
(Richard Harrison) wrote:
>Gary Coffman wrote:
>"No, it would buckle. You cant even reliably do that with 50 feet of
>Rohn 25."
>
Richard Harrison
"---I can see that I`m still not going to have an easily raised AND
lowered for servicing tower."
Some tower manufacturers have a solution in a contraption that travels
up and down the tower. I believe it is called a "hazer". You might get
some user comment, with a little bit of luck.
Richard Harrison
kc5cqa
(Richard Harrison) wrote:
>Gary Coffman wrote:
>"No, it would buckle. You cant even reliably do that with 50 feet of
>Rohn 25."
> U can '''make''' rohn tower (25) be more ' reliable', I did this before I had others
tell me it could not be done. I think what they meant was it could not
be done, and "then" be insured..... At one time I had 68 feet of rohn
25 tower. I welded a hinge plate on the bottom section and 'raised' it
with a telephone pole, my brother gave me. When I first started I
bolted all the section together, and when I 'tried' to lift, the whole
thing it would go ''sway back'', and it would not plum up, when I got
it vertical. I solved that problem by adding a 'tack' weld to the
outside edge leg of the towers where they came together..Over the next
ten to twelve years I lowered and raised that thing about a dozen
times or so. In that period of 'time' I found out you are NOT suppose
to do anything like what I did. I am not saying I would do that again,
but I am saying rohn tower is a lot stronger than you would think. It
seems now any where you look, you see tower used for everything. It
was even in the ''background'' of some of the Star trek series. I have
seen it holding display items above every ones head at some major
stores. Well just my two cents. C. Lorentson 73
Dennis
Thanks,
Dennis
Dennis
Design was OK, implementation was faulty! So, I'm hoping to gain
enough info to prevent more failures (and height!).
Thanks for the info,
Dennis
On Sun, 23 Jan 2000 07:35:12 GMT, kc5...@devtex.net (kc5cqa) wrote:
Gary Coffman
>Is there no easy way to service the top of 50ft towers?
Climb it? :-)
>Seems to me
>that I've read or seen pictures of towers that tilt up and down.
Sure, there are tilt over towers. They're *designed* to be tilt over
towers. You can't do that with just a mast made of fence rail though.
Most tilt over towers are also crank up towers. First you crank it
down to about 30 feet or less, *then* you tilt it over using a gin pole
structure that's an integral part of the mount design. You *don't*
want to be on the short end of a 50 foot or longer moment arm.
TRON
Typical CBer. Get some brains boy!
TRON
TRON
MAX Beam height for CB is 20ft!!!!!!!!!!!!!!!!
Dennis wrote:
> I sort or see what you mean, but I can see that I'm still not going to
> have an easily raised AND lowered for service 50 ft tower...
>
> Thanks for the tips though,
>
> Dennis
>
> On Sat, 22 Jan 2000 09:12:47 -0600 (CST), richard...@webtv.net
> (Richard Harrison) wrote:
>
> >Gary Coffman wrote:
> >"No, it would buckle. You cant even reliably do that with 50 feet of
> >Rohn 25."
> >
> >Gary is right, but there`s a way to raise flimsy towers intact. You
> >should not try it at home without experienced direction and lots of
> >help.
> >
> >It requires (2) stout poles, wooden or whatever, that are strong enough
> >to be uprighted by pivoting on one end.
> >
> >One pole is almost as long as the tower to be uprighted. The other pole
> >is a little over 1/2 the length of the tower to be uprighted. The
> >shorter pole is equipped with a snatch block at the end to be elevated.
> >The longer pole is lashed to the tower at several points.
> >
> >The shorter pole is erected with manpower and guyed off. The longer pole
> >is snatched in the middle and hoisted aloft. Using a tag line attached
> >to the lower end of the tower, it is hauled down and positioned on the
> >tower base.
> >The already attached guy wires are connected to their pre-positioned
> >anchors.
> >
> >Using this method, a trained Radio Free Europe tower crew could erect
> >(4) flimsy Wind Turbine towers and hang a Signal Corps rhombic kit in
> >one day. More time was required to prepare the anchors and to construct
> >transmission and dissipation lines. But, the tower erection was much
> >more efficient than stacking section after section in the air.
> >
> >I want to thank my Portuguese friends who have long been excellent
> >riggers and sailors for this winning idea.
> >
wb
described a crank up tower which i have built. It is guyed and uses ladder
style rungs for each sections. It has held up quite well and i have a 80
footer that has held up for 20 years. I want to remove the guys hence the
inquiry about homebrew towers. Actually i want to build a copy of the US
towers 100 footer. There was also a article in CQ magazine, actually it
might have been QST about a homebrew Big Bertha that seemed straight forward
in terms of welding. Erecting a 130 foot pole is a different matter. Despite
all the warning here about not proceeding. You guys are lucky in the USA
where you have large tower market, we dont so the pickings are scarce or
lean to professional companies like Andrews. So hombrew is a good
alternative. I must admit if i had a local Rohn company i would buy a 100 ft
of 55g and making it rotating. But alas this is not a reality, so the
homebrew 100 foot freestanding crankup will be the project of the future.
Anyway it does not seem like many are homebrewing.
Dennis <den...@nospam.net> wrote in message
news:TaeLOA0ImkUR9g4h9cfyY5neyJ=D...@4ax.com...
> I'd just hate to "almost" see it work. My second attempt blew down!
> Design was OK, implementation was faulty! So, I'm hoping to gain
> enough info to prevent more failures (and height!).
>
> Thanks for the info,
>
> Dennis
>
> On Sun, 23 Jan 2000 07:35:12 GMT, kc5...@devtex.net (kc5cqa) wrote:
>
> >On Sat, 22 Jan 2000 09:12:47 -0600 (CST), richard...@webtv.net
> >(Richard Harrison) wrote:
> >
> >>Gary Coffman wrote:
> >>"No, it would buckle. You cant even reliably do that with 50 feet of
> >>Rohn 25."
Rick Matthews
<18KLOMZIf3IPxbVgjnRwO5=lh...@4ax.com>:
>. First you crank it
>down to about 30 feet or less, *then* you tilt it over using a gin
>pole structure that's an integral part of the mount design. You
>*don't* want to be on the short end of a 50 foot or longer moment
>arm.
Hence the phrase "The short end of the stick"!
CASH MONEY
jli...@earthlink.net
>i am talking about ham beams like a gem quad?
Very general rule of thumb:
In the clear and somewhat higher than all surrounding objects within five
or ten wavelengths.
A realistic _minimum_ height would be somewhere between one half and one
wavelength above the earth. (or other mounting structure, like the top of
a building)
-Jim WA2CEP
Brian
Jim, its been a while, but I recall reading that for 20M, somehow 70' is the
magic number. I sort of remember that at 70' the radiation angle is
optimized.
For DX. For NVIS its an entirely different ballgame. Speaking of Ball
Games, did anyone see the Rams yesterday?
73, Brian
Dennis
If I mount it on the ground next the house, I'd want 50 ft. If I
mounted on the roof, I could settle for 30 ft and maybe tilt it down
on the roof.
And what about "push ups" I can't find any pictures of "push ups".
See them for sale and up to 50 ft, but I can't find out anything else
about them.
Thanks!
Dennis
On Sun, 23 Jan 2000 22:15:02 -0500, Gary Coffman <ke...@bellsouth.net>
wrote:
>On Sat, 22 Jan 2000 23:06:35 -0600, Dennis <den...@nospam.net> wrote:
>>Is there no easy way to service the top of 50ft towers?
>
>Climb it? :-)
>
>>Seems to me
>>that I've read or seen pictures of towers that tilt up and down.
>
>Sure, there are tilt over towers. They're *designed* to be tilt over
>towers. You can't do that with just a mast made of fence rail though.
>Most tilt over towers are also crank up towers. First you crank it
>down to about 30 feet or less, *then* you tilt it over using a gin pole
>structure that's an integral part of the mount design. You *don't*
>want to be on the short end of a 50 foot or longer moment arm.
>
Dennis
Thanks!
DT
On Mon, 24 Jan 2000 12:48:51 +1100, "wb" <will...@yahoo.com> wrote:
>There was an excellent article in QST about 1968 by a ve7????/w6 he
>described a crank up tower which i have built. It is guyed and uses ladder
>style rungs for each sections. It has held up quite well and i have a 80
>footer that has held up for 20 years. I want to remove the guys hence the
>inquiry about homebrew towers. Actually i want to build a copy of the US
>towers 100 footer. There was also a article in CQ magazine, actually it
>might have been QST about a homebrew Big Bertha that seemed straight forward
>in terms of welding. Erecting a 130 foot pole is a different matter. Despite
>all the warning here about not proceeding. You guys are lucky in the USA
>where you have large tower market, we dont so the pickings are scarce or
>lean to professional companies like Andrews. So hombrew is a good
>alternative. I must admit if i had a local Rohn company i would buy a 100 ft
>of 55g and making it rotating. But alas this is not a reality, so the
>homebrew 100 foot freestanding crankup will be the project of the future.
>Anyway it does not seem like many are homebrewing.
>
>
>Dennis <den...@nospam.net> wrote in message
>news:TaeLOA0ImkUR9g4h9cfyY5neyJ=D...@4ax.com...
>> I'd just hate to "almost" see it work. My second attempt blew down!
>> Design was OK, implementation was faulty! So, I'm hoping to gain
>> enough info to prevent more failures (and height!).
>>
>> Thanks for the info,
>>
>> Dennis
>>