I've never done this before so I merely ask advice.

Googling, I find that this seems to be the set of steps to install a
combination TV WiFi (WISP) antenna pole (mast?) in the San Francisco bay
area San Franciscian sediments (mostly chert) where it rarely freezes for
more than a couple of hours but the wind can easily top 100 mph.

I'd like it to be removable (not sure why ... but it just seems like
that's a better way to do it than installing it permanently).

Critique requested on the initial plan:

1. Go to Home Depot and buy large thick steel pipe for the support, maybe
two or three feet long (1.5" ID?); also buy a 15 or 20 foot long steel
pipe (1" OD?) for the mast.
2. Drill & tap a series of set-bolt holes in the top 6 inches of the
large pipe
3. Dig a two-foot deep hole in the soil, about a foot in diameter.
4. Fill the bottom of the hole to the 18 inch deep mark with gravel.
5. Mix concrete and pour the concrete around the large pipe to ground
level with the large pipe sticking up at least six or so inches
6. When set, lower a 15 or 20 foot one-inch OD steel pipe into the larger
pipe, and tighten the set bolts.

Anyone have experience in this type of endeavor that I may learn from
before I do this job?

No experience and little knowledge here, but I suspect there's not
much point in worrying too much about your footing if you're going to
use such a flimsy mast... At the very least you'll need a few hard-
points to guy it. Think much large diameter, in which case the "pipe"
you'll find at HD will be pointlessly thick (and expensive).

On Nov 12, 12:25*pm, Larry Fishel wrote:
No experience and little knowledge here, but I suspect there's not
much point in worrying too much about your footing if you're going to
use such a flimsy mast... At the very least you'll need a few hard-
points to guy it. Think much large diameter, in which case the "pipe"
you'll find at HD will be pointlessly thick (and expensive).




Agree. 1" is going to be way to flimsy for 15 or 20 ft. I'd be
looking at
1 1/2 or 2" for the mast. I'd also go a lot deeper than 2ft with only
18" of concrete. I'd probably go 4 ft deep using a large sona tube.

I never tried tapping a pipe like that for set bolts. The pipe wall
is not very thick
and I wonder what holding power it will have. Ideally, I'd weld a nut
on it and skip the tapping.

Alternatively, some googling might find a ready made kit with all
the components.

On Nov 12, 12:42*pm, "
wrote:
On Nov 12, 12:25*pm, Larry Fishel wrote:

No experience and little knowledge here, but I suspect there's not
much point in worrying too much about your footing if you're going to
use such a flimsy mast... At the very least you'll need a few hard-
points to guy it. Think much large diameter, in which case the "pipe"
you'll find at HD will be pointlessly thick (and expensive).

Agree. *1" is going to be way to flimsy for 15 or 20 ft. *I'd be
looking at
1 1/2 or 2" for the mast. *I'd also go a lot deeper than 2ft with only
18" of concrete. *I'd probably go 4 ft deep using a large sona tube.

I never tried tapping a pipe like that for set bolts. *The pipe wall
is not very thick
and I wonder what holding power it will have. *Ideally, I'd weld a nut
on it and skip the tapping.

Alternatively, some googling might find a ready made kit with all
the components.

check with local amatuer group for advice.....

worker bee wrote:

Googling, I find that this seems to be the set of steps to install
a combination TV WiFi (WISP) antenna pole (mast?) in the San
Francisco bay area San Franciscian sediments (mostly chert)
where it rarely freezes for more than a couple of hours but
the wind can easily top 100 mph.

The wifi antenna will not be any significant wind load.

You'd have to specify what TV antenna you're looking at. It's either
going to be a pure UHF antenna ("bow-tie" / Gray-hoverman or Yagi) or a
combination UHF / VHF. This will depend on what TV channels (real or RF
channels, not virtual channels) you want to receive, and how far away
they are.

Go to the website "tvfool.com" and enter your address (or somewhere
relatively close if don't want to give it your exact street address) and
you'll get a map diagram and chart showing what TV stations are around
you (up to about 100 miles away) and your likelyhood of receiving them.

A UHF or combination UHF-VHF-hi antenna can present a moderately large
wind load.

If you're really going to build for a 100 mph wind event, a single mast
(even if it's 2.5" OD steel pipe) will not take that wind if it's more
than 20 feet high with a medium-sized antenna.

You haven't said if this mast is free-standing (in the middle of your
back yard or some other relatively open space) or if it's running up
along the side of your house (or some other structure) where it can be
supported (tied) to the structure somewhere higher above ground.

There's also the possibility of supporting the mast with guy wires.

Do you intend to have an antenna rotor? Again, the map diagram that
TVfool gives you will tell you if the antenna can be fixed in one
direction to receive the desired (or the majority) of available
channels.

As others have mentioned, 18" worth of concrete is not enough.

I would use a 1 or 2-man gas-powered post-hole driller to drill an 8" or
10" diameter hole, 4 feet deep (or even 5 feet using a drill
extension). Then set a sono-tube into the hole and your pipe and pour
in the concrete. You won't need a 12" diameter hole (it's a bitch to
drill a hole that size compared to 8" or 10"). You can throw some
re-bar into the hole before you pour in the concrete.

Mixing concrete is not exactly a science, but with a little bit of care
and extra preparation you can make a very strong concrete mix yourself,
instead of the pre-packaged garbage you get from the big-box stores.

And as others have mentioned, a 1-inch pipe is way too small, even for a
10' mast. You want a minimum 2.5" pipe if you're going to 20-feet, and
even I wouldn't want to do that without some support guy-wires attached
to it somewhere.

worker bee wrote:
I've never done this before so I merely ask advice.

Googling, I find that this seems to be the set of steps to install a
combination TV WiFi (WISP) antenna pole (mast?) in the San Francisco bay
area San Franciscian sediments (mostly chert) where it rarely freezes for
more than a couple of hours but the wind can easily top 100 mph.

I'd like it to be removable (not sure why ... but it just seems like
that's a better way to do it than installing it permanently).

Critique requested on the initial plan:

1. Go to Home Depot and buy large thick steel pipe for the support, maybe
two or three feet long (1.5" ID?); also buy a 15 or 20 foot long steel
pipe (1" OD?) for the mast.
2. Drill & tap a series of set-bolt holes in the top 6 inches of the
large pipe
3. Dig a two-foot deep hole in the soil, about a foot in diameter.
4. Fill the bottom of the hole to the 18 inch deep mark with gravel.
5. Mix concrete and pour the concrete around the large pipe to ground
level with the large pipe sticking up at least six or so inches
6. When set, lower a 15 or 20 foot one-inch OD steel pipe into the larger
pipe, and tighten the set bolts.

Anyone have experience in this type of endeavor that I may learn from
before I do this job?

Some thoughts.
You can buy high strength steel pipe that can do this job, but probably
want it somewhat larger than 1". This is NOT water pipe you get at Home
Depot. You don't want it bending in the breeze.

Make sure neither pipe is closed at the bottom. Gravel is good until
you let the pipe work its way thru and plug up with dirt during
installation.

You want a lump on the outside of the pipe in the concrete.
Smooth pipe risks working loose and rotating when the antenna
applies torque. Once the pipe starts moving in the concrete, the
support will deteriorate rapidly.

I'd worry about corrosion that near to the ocean. The pipes need to
be a snug fit. But, it won't be long before they're rusted together
and your pipe won't be removable any more.

If the pipes are not a snug fit, you're hozed. You need at least two
solid mounting points as far apart as possible. The pips banging around
in the wind will drive you nuts while the mounts grind their way thru
the metal.

The usual solution is to put the pipe at the end of the house and
support it at the apex of the roof. That turns your iffy project
into a no-brainer. You won't need any concrete at all.
Guy wires can help a lot.

120MPH IS A LOT OF WIND.

On Nov 12, 9:02*am, worker bee wrote:
I've never done this before so I merely ask advice.

Googling, I find that this seems to be the set of steps to install a
combination TV WiFi (WISP) antenna pole (mast?) in the San Francisco bay
area San Franciscian sediments (mostly chert) where it rarely freezes for
more than a couple of hours but the wind can easily top 100 mph.

I'd like it to be removable (not sure why ... but it just seems like
that's a better way to do it than installing it permanently).

Critique requested on the initial plan:

1. Go to Home Depot and buy large thick steel pipe for the support, maybe
two or three feet long (1.5" ID?); also buy a 15 or 20 foot long steel
pipe (1" OD?) for the mast.
2. Drill & tap a series of set-bolt holes in the top 6 inches of the
large pipe
3. Dig a two-foot deep hole in the soil, about a foot in diameter.
4. Fill the bottom of the hole to the 18 inch deep mark with gravel.
5. Mix concrete and pour the concrete around the large pipe to ground
level with the large pipe sticking up at least six or so inches
6. When set, lower a 15 or 20 foot one-inch OD steel pipe into the larger
pipe, and tighten the set bolts.

Anyone have experience in this type of endeavor that I may learn from
before I do this job?

better plan....

Take a look at mast / antenna combos online.
The mast / antenna combo that suits your requirements will have a
footing suggestion for you.

A 1" or even a 1.5" pipe will be way too flexible for your application
at a 20' height.

Antenna masts are very often three sided frames made of triangular
elements much stiffer than a flag pole pipe.

Even an school yard tetherball pole will have 2" pipe and it's only
~8' tall.

cheers
Bob

On 11/12/2011 10:14 PM, DD_BobK wrote:
On Nov 12, 9:02 am, worker wrote:
I've never done this before so I merely ask advice.

Googling, I find that this seems to be the set of steps to install a
combination TV WiFi (WISP) antenna pole (mast?) in the San Francisco bay
area San Franciscian sediments (mostly chert) where it rarely freezes for
more than a couple of hours but the wind can easily top 100 mph.

I'd like it to be removable (not sure why ... but it just seems like
that's a better way to do it than installing it permanently).

Critique requested on the initial plan:

1. Go to Home Depot and buy large thick steel pipe for the support, maybe
two or three feet long (1.5" ID?); also buy a 15 or 20 foot long steel
pipe (1" OD?) for the mast.
2. Drill& tap a series of set-bolt holes in the top 6 inches of the
large pipe
3. Dig a two-foot deep hole in the soil, about a foot in diameter.
4. Fill the bottom of the hole to the 18 inch deep mark with gravel.
5. Mix concrete and pour the concrete around the large pipe to ground
level with the large pipe sticking up at least six or so inches
6. When set, lower a 15 or 20 foot one-inch OD steel pipe into the larger
pipe, and tighten the set bolts.

Anyone have experience in this type of endeavor that I may learn from
before I do this job?

better plan....

Take a look at mast / antenna combos online.
The mast / antenna combo that suits your requirements will have a
footing suggestion for you.

A 1" or even a 1.5" pipe will be way too flexible for your application
at a 20' height.

Antenna masts are very often three sided frames made of triangular
elements much stiffer than a flag pole pipe.

Even an school yard tetherball pole will have 2" pipe and it's only
~8' tall.

cheers
Bob

Pipe is also brittle, and can't sway in breeze. Around here they use
fence pipe, like the stuff used for top rails. It can flex without
kinking. 20' mast will require guying. 3-sided tilt-up tower is what I
would aim for.

Google 'ARRL handbook' for some old-school instructions on creating your
own tower from low-dollar parts.

--
aem sends...

On Sat, 12 Nov 2011 17:02:41 +0000 (UTC), worker bee
wrote:

I've never done this before so I merely ask advice.

Googling, I find that this seems to be the set of steps to install a
combination TV WiFi (WISP) antenna pole (mast?) in the San Francisco bay
area San Franciscian sediments (mostly chert) where it rarely freezes for
more than a couple of hours but the wind can easily top 100 mph.

I'd like it to be removable (not sure why ... but it just seems like
that's a better way to do it than installing it permanently).

Critique requested on the initial plan:

1. Go to Home Depot and buy large thick steel pipe for the support, maybe
two or three feet long (1.5" ID?); also buy a 15 or 20 foot long steel
pipe (1" OD?) for the mast.
2. Drill & tap a series of set-bolt holes in the top 6 inches of the
large pipe
3. Dig a two-foot deep hole in the soil, about a foot in diameter.
4. Fill the bottom of the hole to the 18 inch deep mark with gravel.
5. Mix concrete and pour the concrete around the large pipe to ground
level with the large pipe sticking up at least six or so inches
6. When set, lower a 15 or 20 foot one-inch OD steel pipe into the larger
pipe, and tighten the set bolts.

Anyone have experience in this type of endeavor that I may learn from
before I do this job?

Get some six inch well casing. Dig a hole at least 30 feet deep and
set the pipe with 70 yards of concrete, being sure the pad is at least
10 ft. x 10 ft. and 14 feet deep. Attach your antenna and watch tv
for 100 years or more.

If your TV antenna has any size to it you should not use what you
stated.

There are all kinds of pipe available but for best results you should
use hardened light weight pipe. This type of pipe is specifically made
for use as a mast pipe. Standard water pipe is just to heavy.
It will use its own weight to help bend itself when rocking in heavy
wind. Use guy wires if practical.


Use this page as a guide http://www.texastowers.com/towerhardware.htm

"worker bee" wrote in message
...
I've never done this before so I merely ask advice.

Googling, I find that this seems to be the set of steps to install a
combination TV WiFi (WISP) antenna pole (mast?) in the San Francisco bay
area San Franciscian sediments (mostly chert) where it rarely freezes for
more than a couple of hours but the wind can easily top 100 mph.

I'd like it to be removable (not sure why ... but it just seems like
that's a better way to do it than installing it permanently).

Critique requested on the initial plan:

1. Go to Home Depot and buy large thick steel pipe for the support, maybe
two or three feet long (1.5" ID?); also buy a 15 or 20 foot long steel
pipe (1" OD?) for the mast.
2. Drill & tap a series of set-bolt holes in the top 6 inches of the
large pipe
3. Dig a two-foot deep hole in the soil, about a foot in diameter.
4. Fill the bottom of the hole to the 18 inch deep mark with gravel.
5. Mix concrete and pour the concrete around the large pipe to ground
level with the large pipe sticking up at least six or so inches
6. When set, lower a 15 or 20 foot one-inch OD steel pipe into the larger
pipe, and tighten the set bolts.

Anyone have experience in this type of endeavor that I may learn from
before I do this job?

In article , worker bee
wrote:

I've never done this before so I merely ask advice.

Googling, I find that this seems to be the set of steps to install a
combination TV WiFi (WISP) antenna pole (mast?) in the San Francisco bay
area San Franciscian sediments (mostly chert) where it rarely freezes for
more than a couple of hours but the wind can easily top 100 mph.

I'd like it to be removable (not sure why ... but it just seems like
that's a better way to do it than installing it permanently).

Critique requested on the initial plan:

1. Go to Home Depot and buy large thick steel pipe for the support, maybe
two or three feet long (1.5" ID?); also buy a 15 or 20 foot long steel
pipe (1" OD?) for the mast.
2. Drill & tap a series of set-bolt holes in the top 6 inches of the
large pipe
3. Dig a two-foot deep hole in the soil, about a foot in diameter.
4. Fill the bottom of the hole to the 18 inch deep mark with gravel.
5. Mix concrete and pour the concrete around the large pipe to ground
level with the large pipe sticking up at least six or so inches
6. When set, lower a 15 or 20 foot one-inch OD steel pipe into the larger
pipe, and tighten the set bolts.

Anyone have experience in this type of endeavor that I may learn from
before I do this job?

just a minor curiousity, but what requirements do the planning
commission/building department require...it is SF and I can't imagine you'd get
away doing this without an approved set of plans

OTOH, i'd consider buying a surplus telephone pole and digging a hole about 25%
the length of the pole to place it in

Malcom \"Mal\" Reynolds wrote:

OTOH, i'd consider buying a surplus telephone pole and digging a
hole about 25% the length of the pole to place it in

I think a lot of this thread is bull crap.

I'd like to know where in the SF-bay area the OP lives in. Then run
that city through tvfool.com to see what TV stations are in the area.

My gut feeling is that you won't need a 20'+ mast to pick up what-ever
stations are available in the area.

A larger yagi, or a double-bay or quad-bay bowtie, either one with a
good amplifier, can be mounted closer to the ground to compensate for
not having a taller mast.

Home Guy wrote:
Malcom \"Mal\" Reynolds wrote:

OTOH, i'd consider buying a surplus telephone pole and digging a
hole about 25% the length of the pole to place it in

I think a lot of this thread is bull crap.

I'd like to know where in the SF-bay area the OP lives in. Then run
that city through tvfool.com to see what TV stations are in the area.

My gut feeling is that you won't need a 20'+ mast to pick up what-ever
stations are available in the area.

A larger yagi, or a double-bay or quad-bay bowtie, either one with a
good amplifier, can be mounted closer to the ground to compensate for
not having a taller mast.
My personal experience is that HDTV reception is more dependent on
multipath than signal strength.
I've got lots of signal but poor reception. Might have something to
do with the metal pole building 50 feet away.
Height can make a big difference in
a hilly area with lots of reflections.

On Sun, 13 Nov 2011 13:49:36 -0800, "Malcom \"Mal\" Reynolds"
wrote:

just a minor curiousity, but what requirements do the planning
commission/building department require...it is SF and I can't imagine you'd get
away doing this without an approved set of plans

OTOH, i'd consider buying a surplus telephone pole and digging a hole about 25%
the length of the pole to place it in

They dont have "telephone poles" anymore. Many years ago they had the
phone up on the pole, and to make a call, you would have to climb the
pole. I recall seeing this on "Green Acres". But those days are long
gone. Now we have cell phones. Ya know, those annoying things in
your pocket that demand your attention at the worst possible moment,
like when you are 40 feet up on an electrical power pole connecting a
275lb triplex cable, or under your car lifting an automatic
transmission into place. Then after you fall off the pole, or you
drop the tranny on your forehead, you find your cell phone has no
signal. Ahhhh, yes, bring back the good old days, where all we had to
do was climb the telephone pole to make a call!


And, regarding the person who suggested using "guy wires", what if you
would rather have GAL wires. You know, the female variety. Why are
those wires always made just for the guys? That's kind of sexist if
you ask me.

On Nov 13, 5:35*pm, Home Guy wrote:
Malcom \"Mal\" Reynolds wrote:
OTOH, i'd consider buying a surplus telephone pole and digging a
hole about 25% the length of the pole to place it in

I think a lot of this thread is bull crap.

I'd like to know where in the SF-bay area the OP lives in. *Then run
that city through tvfool.com to see what TV stations are in the area.

My gut feeling is that you won't need a 20'+ mast to pick up what-ever
stations are available in the area.

A larger yagi, or a double-bay or quad-bay bowtie, either one with a
good amplifier, can be mounted closer to the ground to compensate for
not having a taller mast.

He did say WiFi, not TV, which means the above is irrelevant.
But even if it were TV, it's not all
that unusual to find a location that needs a 15 or 20ft mast
to pick up TV. Most places you wouldn't need it. But
that doesn't make it BS for someone that does.

" wrote:

I think a lot of this thread is bull crap.

I'd like to know where in the SF-bay area the OP lives in. Then
run that city through tvfool.com to see what TV stations are in
the area.
not having a taller mast.

He did say WiFi, not TV, which means the above is irrelevant.

Go and read the OP again.

He said " a combination TV WiFi (WISP) antenna"

I see "TV" in that question.

But even if it were TV, it's not all that unusual to find a
location that needs a 15 or 20ft mast to pick up TV.

He's in a very populated urban area.

Most places you wouldn't need it. But that doesn't make it
BS for someone that does.

We don't know that he does.

Plugging in "San Francisco" into tv fool gives 17 transmitters that are
LOS (line of sight) which means under 15 miles (most of those are under
5 miles). An indoor antenna would pick up those with little trouble.

About 2-dozen transmitters that are LOS in Oakland. About 2 dozen in
Burlingame that are either LOS or 1-edge (just a little more difficult
to get). 10 LOS in Mountainview. About 2 dozen LOS in San Jose - but
many of those are 40+ miles away but are still listed as strong.

The OP has ****ed off and I have my doubts if we'll see him again, but
if he's reading this he should specify what city he's in, or run the
TVfool analysis on his own location (use 10 ft antenna height) and see
if he really needs a mast.

Putting a wifi antenna on a 20 or 30 foot mast is not really that
useful. You can get routers or wifi base stations that put out more
power, and use better wifi antennas if you want more range.

On Nov 14, 8:58*am, Home Guy wrote:
" wrote:
I think a lot of this thread is bull crap.

I'd like to know where in the SF-bay area the OP lives in. *Then
run that city through tvfool.com to see what TV stations are in
the area.
not having a taller mast.

He did say WiFi, not TV, which means the above is irrelevant.

Go and read the OP again.

He said " a combination TV WiFi (WISP) antenna"

I see "TV" in that question.

Yes, I agree you're right on that one.




But even if it were TV, it's not all that unusual to find a
location that needs a 15 or 20ft mast to pick up TV.

He's in a very populated urban area.

Most places you wouldn't need it. *But that doesn't make it
BS for someone that does.

We don't know that he does.


Plugging in "San Francisco" into tv fool gives 17 transmitters that are
LOS (line of sight) which means under 15 miles (most of those are under
5 miles). *An indoor antenna would pick up those with little trouble.

You been to SF? The terrain is hilly and there are also plenty
of tall buildings in the downtown area. It would not strike me
as BS that someone needs a 15ft mast to receive a decent
signal.


About 2-dozen transmitters that are LOS in Oakland. *About 2 dozen in
Burlingame that are either LOS or 1-edge (just a little more difficult
to get). *10 LOS in Mountainview. *About 2 dozen LOS in San Jose - but
many of those are 40+ miles away but are still listed as strong.

It doesn't matter if there a 2 dozen if the one you really want
to watch is the problem one.



The OP has ****ed off and I have my doubts if we'll see him again, but
if he's reading this he should specify what city he's in, or run the
TVfool analysis on his own location (use 10 ft antenna height) and see
if he really needs a mast.

Somehow I suspect that a guy contemplating putting up
a 15 or 20ft mast has probably figured out that he needs it.
But, who knows?



Putting a wifi antenna on a 20 or 30 foot mast is not really that
useful. *You can get routers or wifi base stations that put out more
power, and use better wifi antennas if you want more range.

On Sat, 12 Nov 2011 09:25:17 -0800, Larry Fishel wrote:

there's not much
point in worrying too much about your footing if you're going to use
such a flimsy mast... Think much large diameter

I'm ok with a thicker & deeper mast if that's what it takes.

On Sat, 12 Nov 2011 09:42:03 -0800, wrote:

I'd probably go 4 ft deep

That's good advice (which others also suggested). So I'll go deeper (I
may need a hole digger corkscrew for that deep of a hole).

Ideally, I'd weld a nut on it and skip the tapping.

Makes sense. It would have stronger threads and can be welded onto both
sides of the pipe hole.

On Sat, 12 Nov 2011 14:10:02 -0500, Home Guy wrote:

The wifi antenna will not be any significant wind load.

Interesting. I would have figured the parabolic dish (even if it's a wire
mesh) would catch the wind more so than the standard protruding Y-shaped
TV antennas I see on people's houses.

You'd have to specify what TV antenna you're looking at.
Go to the website "tvfool.com"

Nice web site. It looks like, at 10 feet antenna height, I'm "green" for:
Analog channel 6 @ 38.7 dbM
Digital channel 32(46.1) CBS @ 39.7 dbM

And, I'm "yellow" for:
Analog channel 2 @ 30.7 dbM
Digital channels 19,38,39,22,8,13 @ a minimum of 21.5 dbM

You haven't said if this mast is free-standing (in the middle of your
back yard or some other relatively open space)

The intent is to be free standing on a hillock in the back yard.

There's also the possibility of supporting the mast with guy wires.

Yuck.

Do you intend to have an antenna rotor?
No. I was hoping to align the WISP antenna for the one signal; and the
ancillary TV antenna to the one or two stations that are best.

As others have mentioned, 18" worth of concrete is not enough.

I see. Looks like I'll be going 3 or 4 feet deep (I had thought concrete
was stronger).

I would use a 1 or 2-man gas-powered post-hole driller to drill an 8" or
10" diameter hole, 4 feet deep (or even 5 feet using a drill extension).

I need to rent one of these babies.

You want a minimum 2.5" pipe if you're going to 20-feet

Will do!

worker bee wrote:

The wifi antenna will not be any significant wind load.

Interesting. I would have figured the parabolic dish (even if it's
a wire mesh) would catch the wind more so than the standard
protruding Y-shaped TV antennas I see on people's houses.

I wouldn't call that a wifi antenna. This is what I normally think of
as a wifi antenna:

http://www.folkstone.ca/main/images/...enna-rpsma.jpg
http://www.zdacomm.com/images/storie...log/AP_CPE.jpg

What your talking about is this:

http://www.gnswireless.com/GNS1405.htm

These are more for point-to-point communication over long distance.
They require aiming, and you should have a line-of-sight to the other
antenna, and that other antenna at the other location should be a
similar type and should be aimed at you.

You might want to look at this yagi-style alternative to the parabolic
one you're thinking of:

http://image.made-in-china.com/2f0j0...WTX-00043-.jpg

But even the parabolic one is really quite small compared to the
"average" TV antenna.

Go to the website "tvfool.com"

Nice web site. It looks like, at 10 feet antenna height, I'm
"green" for: Analog channel 6 @ 38.7 dbM
Digital channel 32(46.1) CBS @ 39.7 dbM

And, I'm "yellow" for:
Analog channel 2 @ 30.7 dbM
Digital channels 19,38,39,22,8,13 @ a minimum of 21.5 dbM

Analog channel 6 is a VHF-low channel, and it's going to require a large
dipole antenna (basically, an FM antenna). Are you mentioning that
channel because it shows up in TVFool's list, or because you really want
to receive it? It must be a low-power repeater or a community channel,
because that's all you can do with analog channels these days. Same
goes with analog channel 2 (the elements or rods for an antenna to
receive channel 2 are very long - about 5 or 6 feet).

You haven't said if this mast is free-standing (in the middle
of your back yard or some other relatively open space)

The intent is to be free standing on a hillock in the back yard.

If you have a chimney on the roof, that's where most people mount
antennas. If you put up a mast, run it along side your house and use
the house as a brace. You won't need to dig any hole.

Do you intend to have an antenna rotor?

No. I was hoping to align the WISP antenna for the one signal;

Yes, I can see that. Mount that antenna somewhere to your house. I
don't know if you have a detached house, or if you're part of a tenament
building / brownstone, so obviously there will be various ways to mount
an antenna given each situation.

As others have mentioned, 18" worth of concrete is not enough.

I see. Looks like I'll be going 3 or 4 feet deep (I had thought
concrete was stronger).

It's very strong when it's loaded in compression, but not very strong in
bending.

You want a minimum 2.5" pipe if you're going to 20-feet

Will do!

I strongly suggest you mount these antennas to your house, and not a
pole in the middle of your yard. The directional long-range wifi
antenna doesn't have to be mounted to the same mast as the TV antenna.

Do you really want to mess up the usefullness, utility, access and
enjoyment of your back yard by putting an antenna mast in the middle of
it?

On Nov 16, 8:17*am, Home Guy wrote:
worker bee wrote:
The wifi antenna will not be any significant wind load.

Interesting. I would have figured the parabolic dish (even if it's
a wire mesh) would catch the wind more so than the standard
protruding Y-shaped TV antennas I see on people's houses.

I wouldn't call that a wifi antenna. *This is what I normally think of
as a wifi antenna:

http://www.folkstone.ca/main/images/...log/AP_CPE.jpg

What your talking about is this:

http://www.gnswireless.com/GNS1405.htm

These are more for point-to-point communication over long distance.
They require aiming, and you should have a line-of-sight to the other
antenna, and that other antenna at the other location should be a
similar type and should be aimed at you.

You might want to look at this yagi-style alternative to the parabolic
one you're thinking of:

http://image.made-in-china.com/2f0j0...or-WiFi-Antenn...

But even the parabolic one is really quite small compared to the
"average" TV antenna.

Go to the website "tvfool.com"

Nice web site. It looks like, at 10 feet antenna height, I'm
"green" for: Analog channel 6 @ 38.7 dbM
Digital channel 32(46.1) CBS @ 39.7 dbM

And, I'm "yellow" for:
Analog channel 2 @ 30.7 dbM
Digital channels 19,38,39,22,8,13 @ a minimum of 21.5 dbM

Analog channel 6 is a VHF-low channel, and it's going to require a large
dipole antenna (basically, an FM antenna). *Are you mentioning that
channel because it shows up in TVFool's list, or because you really want
to receive it? *It must be a low-power repeater or a community channel,
because that's all you can do with analog channels these days. *Same
goes with analog channel 2 (the elements or rods for an antenna to
receive channel 2 are very long - about 5 or 6 feet).

You haven't said if this mast is free-standing (in the middle
of your back yard or some other relatively open space)

The intent is to be free standing on a hillock in the back yard.

If you have a chimney on the roof, that's where most people mount
antennas. *If you put up a mast, run it along side your house and use
the house as a brace. *You won't need to dig any hole.

Do you intend to have an antenna rotor?
No. I was hoping to align the WISP antenna for the one signal;

Yes, I can see that. *Mount that antenna somewhere to your house. *I
don't know if you have a detached house, or if you're part of a tenament
building / brownstone, so obviously there will be various ways to mount
an antenna given each situation.

As others have mentioned, 18" worth of concrete is not enough.

I see. Looks like I'll be going 3 or 4 feet deep (I had thought
concrete was stronger).

It's very strong when it's loaded in compression, but not very strong in
bending.

It's not just the issue of the concrete failing. With an 18" deep
hole
about a foot in diameter, the concrete could remain intact, secured
to the pipe, and the whole thing could rock back and forth in the
ground until it topples over. In other words, there isn't enough mass
and/or that mass isn't held firmly enough in the ground.

worker bee wrote:
I've never done this before so I merely ask advice.

Googling, I find that this seems to be the set of steps to install a
combination TV WiFi (WISP) antenna pole (mast?) in the San Francisco
bay area San Franciscian sediments (mostly chert) where it rarely
freezes for more than a couple of hours but the wind can easily top
100 mph.

I'd like it to be removable (not sure why ... but it just seems like
that's a better way to do it than installing it permanently).

Critique requested on the initial plan:

1. Go to Home Depot and buy large thick steel pipe for the support,
maybe two or three feet long (1.5" ID?); also buy a 15 or 20 foot
long steel pipe (1" OD?) for the mast.
2. Drill & tap a series of set-bolt holes in the top 6 inches of the
large pipe
3. Dig a two-foot deep hole in the soil, about a foot in diameter.
4. Fill the bottom of the hole to the 18 inch deep mark with gravel.
5. Mix concrete and pour the concrete around the large pipe to ground
level with the large pipe sticking up at least six or so inches
6. When set, lower a 15 or 20 foot one-inch OD steel pipe into the
larger pipe, and tighten the set bolts.

Anyone have experience in this type of endeavor that I may learn from
before I do this job?

Regular telephone poles have about 1/3rd of their length below the surface.
So, if you get a 30' pole and put it in a hole ten feet deep, you should be
okay. (The 30% factor is for one-foot diameter wooden poles. A thinner metal
pole may require more depth.)

On 11/16/2011 4:22 PM, HeyBub wrote:
worker bee wrote:
I've never done this before so I merely ask advice.

Googling, I find that this seems to be the set of steps to install a
combination TV WiFi (WISP) antenna pole (mast?) in the San Francisco
bay area San Franciscian sediments (mostly chert) where it rarely
freezes for more than a couple of hours but the wind can easily top
100 mph.

I'd like it to be removable (not sure why ... but it just seems like
that's a better way to do it than installing it permanently).

Critique requested on the initial plan:

1. Go to Home Depot and buy large thick steel pipe for the support,
maybe two or three feet long (1.5" ID?); also buy a 15 or 20 foot
long steel pipe (1" OD?) for the mast.
2. Drill& tap a series of set-bolt holes in the top 6 inches of the
large pipe
3. Dig a two-foot deep hole in the soil, about a foot in diameter.
4. Fill the bottom of the hole to the 18 inch deep mark with gravel.
5. Mix concrete and pour the concrete around the large pipe to ground
level with the large pipe sticking up at least six or so inches
6. When set, lower a 15 or 20 foot one-inch OD steel pipe into the
larger pipe, and tighten the set bolts.

Anyone have experience in this type of endeavor that I may learn from
before I do this job?

Regular telephone poles have about 1/3rd of their length below the surface.
So, if you get a 30' pole and put it in a hole ten feet deep, you should be
okay. (The 30% factor is for one-foot diameter wooden poles. A thinner metal
pole may require more depth.)




Typical pole depth for power poles, fence posts, etc is 10% of pole
length plus 2 feet. A 30' power pole is set 5-6' in the ground. If
the pole will have a sign or other wind catching feature, the diameter
and depth increase. Flagpoles don't need depth as much as they need
mass. A can is set in concrete, the pole is set in the can with wedges
and sand - if it were set in concrete it would snap off at the ground so
it needs the cushion of sand.