Thunderbolt cabling questions
And make sure that the flange is being bolted into a stud and not just the
sheathing. A good gust could pop it off especially if the arm is long.
Great idea though!
Dave (who just got a Tbolt and waiting on an antenna) I am doing a tower
for my ham radio stuff and want to put the Tbolt on the other side of the
house to gain some isolation.
-----Original Message-----
From: time-nuts-bounces@febo.com
[mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Sunday, June 10, 2012 17:53
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt cabling questions
Hi
Sorry for the blank.
The easy way to mount the antenna:
Head over to Home Depot and get a 1" Tee, a 1" flange, a 1"
nipple, a 12" to 18" 1" pipe, and a 6" long 1" pipe.
The antenna goes on top of the 18" pipe. That screws into the
tee. The bottom of the Tee gets the 6" pipe. Coax runs
straight through the 18" and 6" pipe. Nipple goes to the
flange and the tee. Flange mounts to the house. If you need
to get a bit further out, change out the nipple for a piece of pipe.
Spray paint it all black ( or what ever) and move on.
Bob
On Jun 10, 2012, at 7:43 PM, Jim Lux wrote:
On 6/10/12 4:24 PM, Chris Albertson wrote:
On Sun, Jun 10, 2012 at 2:50 PM,bg@lysator.liu.se wrote:
... 3m
of antenna cable is no problem. Antenna position is more
important than
the exact type of antenna. I'd rather have a decent
antenna at a very good
site, than a very good antenna at a slightly worse antenna site
3M is trivial. 30M will work fine too.
I agree about the location really mattering more than
anything else. What
I did was drill a 2" hole through the roof up from the
attic and push a 10
foot gallanvised iron plumbing pipe up.
you would probably want appropriate flashing around that to
prevent water (and vermin) ingress.
The antenna sits on thop ithe
pipe and is higher then the roof top ridge and then the
cable go down the
center of the pipe. I pipe flange on top of the pipe
makes a perfect
mounting platform. I used a timing antenna comes inside
a white pointed
plastic radome. These sell for just under $30 on eBay.
Maybe it is
coincidence or not but the four holes pin the standard
pipe flange match up
with the four holes in the bottom of my antenna and there
is enough room
inside the hole in the center for an "N" connector. It
is worth getting
the antenna "done right" because it is the most important
part of the
entire system. Those dome type antenna are worth it.
the shape is
designed to shed both bird poop, and snow. Birds can be
an issue with a
flat top antenna, no snow here.
You probably get snow every few decades (it snowed in
Malibu a couple years ago, for instance), but I wouldn't
worry about snow loads, even so. <grin>
HOWEVER, your scheme is going to be tricky to pass muster
with the National Electrical Code. Two aspects need attention:
You need to have a ground wire from the mast to the ground point
and
You need to have some form of ground of the coax shield at
the point where the coax enters the building. (a "listed
antenna discharge unit" is the usual way).
While Southern California isn't exactly the lightning
capital of the world, we do get some. A bigger concern (and
the primary reason for the code requirement) is that above
ground power lines can come down and touch your antenna.
And someone living in a more lightning prone area is going
to want to take those precautions.
The installations I've seen typically use the same general
"pipe" scheme (using rigid conduit, which looks a lot like
pipe, but has a smooth inside with no burrs) to a box on the
roof, and then regular conduit running down the outside of
the building. Then at the point of entrance, the ground
bonding conductor goes from the conduit to ground, and
there's a coax grounding block in a box at the place where
the hole in the wall is.
Granted, if lightning does hit, everything connected to the
antenna is going to fry, unless you have some sort of
reradiation scheme to provide an air gap. That's what we do
when we test GPS receivers destined for space, where you
don't want to take the risk of killing the expensive flight hardware.
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
On Sun, Jun 10, 2012 at 4:43 PM, Jim Lux jimlux@earthlink.net wrote:
HOWEVER, your scheme is going to be tricky to pass muster with the
National Electrical Code. Two aspects need attention:
You need to have a ground wire from the mast to the ground point
and
You need to have some form of ground of the coax shield at the point
where the coax enters the building. (a "listed antenna discharge unit" is
the usual way).
Yes, all true. I didn't really want to right a book about it. Yes there
is flashing around the pipe. It is handled the same is for other pipes
that come up through the rook to vent plumping. And yes you ground the
pipe just like you ground an old off-the-air TV antenna mast and so on.
My VHF (two and four meter) antenna and by HF wire antenna all have
lightening arasters and big ground rod systems, and the ground rods are
tried together an.
But you know what? If you simply place an automotive "puck" type GPS
antenna on your roof you have to do the same thing. It must be grounded
the same way, same lightening protection and so on. So in the end you may
as well put up a professional looking and permanent steel mast. It is not
that much more work.
Chris Albertson
Redondo Beach, California
I did that once and thought the bends in the pipe looked ugly. I wanted a
simple vertical mast. The simple mast is also stronger because I can use
"U" bolts to secure it to a rafter and a floor joist that are about four
feet apart. Results in the very strong installation. It is build exactly
like a plumbing vent, just a long pipe with the last few feet above the
roof. The coax run is completely 100% out of the weather.
On Sun, Jun 10, 2012 at 7:06 PM, DaveH info@blackmountainforge.com wrote:
The easy way to mount the antenna:
Head over to Home Depot and get a 1" Tee, a 1" flange, a 1"
nipple, a 12" to 18" 1" pipe, and a 6" long 1" pipe.
The antenna goes on top of the 18" pipe. That screws into the
tee. The bottom of the Tee gets the 6" pipe. Coax runs
straight through the 18" and 6" pipe. Nipple goes to the
flange and the tee. Flange mounts to the house. If you need
to get a bit further out, change out the nipple for a piece of pipe.
Spray paint it all black ( or what ever) and move on.
Bob
On Jun 10, 2012, at 7:43 PM, Jim Lux wrote:
On 6/10/12 4:24 PM, Chris Albertson wrote:
On Sun, Jun 10, 2012 at 2:50 PM,bg@lysator.liu.se wrote:
... 3m
of antenna cable is no problem. Antenna position is more
important than
the exact type of antenna. I'd rather have a decent
antenna at a very good
site, than a very good antenna at a slightly worse antenna site
3M is trivial. 30M will work fine too.
I agree about the location really mattering more than
anything else. What
I did was drill a 2" hole through the roof up from the
attic and push a 10
foot gallanvised iron plumbing pipe up.
you would probably want appropriate flashing around that to
prevent water (and vermin) ingress.
The antenna sits on thop ithe
pipe and is higher then the roof top ridge and then the
cable go down the
center of the pipe. I pipe flange on top of the pipe
makes a perfect
mounting platform. I used a timing antenna comes inside
a white pointed
plastic radome. These sell for just under $30 on eBay.
Maybe it is
coincidence or not but the four holes pin the standard
pipe flange match up
with the four holes in the bottom of my antenna and there
is enough room
inside the hole in the center for an "N" connector. It
is worth getting
the antenna "done right" because it is the most important
part of the
entire system. Those dome type antenna are worth it.
the shape is
designed to shed both bird poop, and snow. Birds can be
an issue with a
flat top antenna, no snow here.
You probably get snow every few decades (it snowed in
Malibu a couple years ago, for instance), but I wouldn't
worry about snow loads, even so. <grin>
HOWEVER, your scheme is going to be tricky to pass muster
with the National Electrical Code. Two aspects need attention:
You need to have a ground wire from the mast to the ground point
and
You need to have some form of ground of the coax shield at
the point where the coax enters the building. (a "listed
antenna discharge unit" is the usual way).
While Southern California isn't exactly the lightning
capital of the world, we do get some. A bigger concern (and
the primary reason for the code requirement) is that above
ground power lines can come down and touch your antenna.
And someone living in a more lightning prone area is going
to want to take those precautions.
The installations I've seen typically use the same general
"pipe" scheme (using rigid conduit, which looks a lot like
pipe, but has a smooth inside with no burrs) to a box on the
roof, and then regular conduit running down the outside of
the building. Then at the point of entrance, the ground
bonding conductor goes from the conduit to ground, and
there's a coax grounding block in a box at the place where
the hole in the wall is.
Granted, if lightning does hit, everything connected to the
antenna is going to fry, unless you have some sort of
reradiation scheme to provide an air gap. That's what we do
when we test GPS receivers destined for space, where you
don't want to take the risk of killing the expensive flight hardware.
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
--
Chris Albertson
Redondo Beach, California
Totally agree
On Jun 10, 2012, at 19:34, Chris Albertson albertson.chris@gmail.com wrote:
On Sun, Jun 10, 2012 at 4:43 PM, Jim Lux jimlux@earthlink.net wrote:
HOWEVER, your scheme is going to be tricky to pass muster with the
National Electrical Code. Two aspects need attention:
You need to have a ground wire from the mast to the ground point
and
You need to have some form of ground of the coax shield at the point
where the coax enters the building. (a "listed antenna discharge unit" is
the usual way).
Yes, all true. I didn't really want to right a book about it. Yes there
is flashing around the pipe. It is handled the same is for other pipes
that come up through the rook to vent plumping. And yes you ground the
pipe just like you ground an old off-the-air TV antenna mast and so on.
My VHF (two and four meter) antenna and by HF wire antenna all have
lightening arasters and big ground rod systems, and the ground rods are
tried together an.
But you know what? If you simply place an automotive "puck" type GPS
antenna on your roof you have to do the same thing. It must be grounded
the same way, same lightening protection and so on. So in the end you may
as well put up a professional looking and permanent steel mast. It is not
that much more work.
Chris Albertson
Redondo Beach, California
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Hi
I was concerned about the appearance before I did the first one. After putting several up, they all look pretty good. The mast portion looks straight from the ground and it's actually smaller than any conventional mast. The black paint does indeed help out a little in hiding the tee it's self.
Yes indeed grounding needs to be done, I figured the post was long enough already.
Bob
On Jun 10, 2012, at 10:40 PM, Chris Albertson wrote:
I did that once and thought the bends in the pipe looked ugly. I wanted a
simple vertical mast. The simple mast is also stronger because I can use
"U" bolts to secure it to a rafter and a floor joist that are about four
feet apart. Results in the very strong installation. It is build exactly
like a plumbing vent, just a long pipe with the last few feet above the
roof. The coax run is completely 100% out of the weather.
On Sun, Jun 10, 2012 at 7:06 PM, DaveH info@blackmountainforge.com wrote:
The easy way to mount the antenna:
Head over to Home Depot and get a 1" Tee, a 1" flange, a 1"
nipple, a 12" to 18" 1" pipe, and a 6" long 1" pipe.
The antenna goes on top of the 18" pipe. That screws into the
tee. The bottom of the Tee gets the 6" pipe. Coax runs
straight through the 18" and 6" pipe. Nipple goes to the
flange and the tee. Flange mounts to the house. If you need
to get a bit further out, change out the nipple for a piece of pipe.
Spray paint it all black ( or what ever) and move on.
Bob
On Jun 10, 2012, at 7:43 PM, Jim Lux wrote:
On 6/10/12 4:24 PM, Chris Albertson wrote:
On Sun, Jun 10, 2012 at 2:50 PM,bg@lysator.liu.se wrote:
... 3m
of antenna cable is no problem. Antenna position is more
important than
the exact type of antenna. I'd rather have a decent
antenna at a very good
site, than a very good antenna at a slightly worse antenna site
3M is trivial. 30M will work fine too.
I agree about the location really mattering more than
anything else. What
I did was drill a 2" hole through the roof up from the
attic and push a 10
foot gallanvised iron plumbing pipe up.
you would probably want appropriate flashing around that to
prevent water (and vermin) ingress.
The antenna sits on thop ithe
pipe and is higher then the roof top ridge and then the
cable go down the
center of the pipe. I pipe flange on top of the pipe
makes a perfect
mounting platform. I used a timing antenna comes inside
a white pointed
plastic radome. These sell for just under $30 on eBay.
Maybe it is
coincidence or not but the four holes pin the standard
pipe flange match up
with the four holes in the bottom of my antenna and there
is enough room
inside the hole in the center for an "N" connector. It
is worth getting
the antenna "done right" because it is the most important
part of the
entire system. Those dome type antenna are worth it.
the shape is
designed to shed both bird poop, and snow. Birds can be
an issue with a
flat top antenna, no snow here.
You probably get snow every few decades (it snowed in
Malibu a couple years ago, for instance), but I wouldn't
worry about snow loads, even so. <grin>
HOWEVER, your scheme is going to be tricky to pass muster
with the National Electrical Code. Two aspects need attention:
You need to have a ground wire from the mast to the ground point
and
You need to have some form of ground of the coax shield at
the point where the coax enters the building. (a "listed
antenna discharge unit" is the usual way).
While Southern California isn't exactly the lightning
capital of the world, we do get some. A bigger concern (and
the primary reason for the code requirement) is that above
ground power lines can come down and touch your antenna.
And someone living in a more lightning prone area is going
to want to take those precautions.
The installations I've seen typically use the same general
"pipe" scheme (using rigid conduit, which looks a lot like
pipe, but has a smooth inside with no burrs) to a box on the
roof, and then regular conduit running down the outside of
the building. Then at the point of entrance, the ground
bonding conductor goes from the conduit to ground, and
there's a coax grounding block in a box at the place where
the hole in the wall is.
Granted, if lightning does hit, everything connected to the
antenna is going to fry, unless you have some sort of
reradiation scheme to provide an air gap. That's what we do
when we test GPS receivers destined for space, where you
don't want to take the risk of killing the expensive flight hardware.
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
--
Chris Albertson
Redondo Beach, California
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
10/06/2012 22:26
My Thunderbolt, PSU and antenna should arrive this week. I would like
to put out it outside my shack, which is an upstairs room in a bungalow.
Outside of the plasterboard walls of my room is a big empty roof space. Can
I put the TB in there, with it's PSU and feed the antenna wire out
under a ridge tile and have the antenna itself on an aluminium bracket
with a clear sky view on the ridge of the roof.? It would mean a cable
from the output of the TB back into my room of about 10 or so feet.
Anything I need to watch for, does the PSU run particularly warm? How
much current do they draw off the mains, it's not going to cost a bomb
leaving it on 24 hours a day, is it? Thanks.
11/06/2012 13:43
Thanks for the replies, I never intended to have the TB unit itself
outside, just in the roof space, which pretty much follows the
temperature of my room anyway, as I only heat it in very cold weather
as the room pretty much follows the temperature of the rest of the
hose.
The stuff arrived this morning, with regard to the antenna, does it
need to see the sky from horizon to horizon? Or would a mount a few
feet above the gutter of the bungalow be adequate? I am not sure how
many satellites it needs to see to work properly. A mount about 3 feet
above the gutter line would be neat and trivial. Thanks again.
--
Best Regards,
Chris Wilson.
On Mon, Jun 11, 2012 at 3:28 AM, Bob Camp lists@rtty.us wrote:
Hi
I was concerned about the appearance before I did the first one. After
putting several up, they all look pretty good. The mast portion looks
straight from the ground and it's actually smaller than any conventional
mast. The black paint does indeed help out a little in hiding the tee it's
self.
I've tried camouflaging the masts. Paint the upper parts sky blue with
puffs of white spray paint over the blue I paint the bottom part black or
dark green. Not perfect, I have a 40 foot pole on the back yard fence
that is still visible from the street but maybe it helps. Battle ship
grey works well too.
Chris Albertson
Redondo Beach, California
Hi
Assuming you are in the northern hemisphere ...
You want a good view of the southern sky. You don't need to "see" due north
+/- about 45 degrees unless you are closer to the north pole than I suspect
you are. There are some minor benefits to being well above ground, but once
you get a good sky view things will work well. I would pick a location
that's 12" off the roof with a good view over one that's on a 40' mast in
the trees.
Ideally you would like to control the TBolt's temperature to within a degree
or two. That can be done with fans or a variety of other approaches. What
you want to avoid are rapid temperature ramps. Sun comes up and TBolt goes
up 30 degrees is not a recipe for ultimate stability.
Bob
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Chris Wilson
Sent: Monday, June 11, 2012 8:47 AM
To: Chris Wilson; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt cabling questions
10/06/2012 22:26
My Thunderbolt, PSU and antenna should arrive this week. I would like
to put out it outside my shack, which is an upstairs room in a bungalow.
Outside of the plasterboard walls of my room is a big empty roof space.
Can
I put the TB in there, with it's PSU and feed the antenna wire out
under a ridge tile and have the antenna itself on an aluminium bracket
with a clear sky view on the ridge of the roof.? It would mean a cable
from the output of the TB back into my room of about 10 or so feet.
Anything I need to watch for, does the PSU run particularly warm? How
much current do they draw off the mains, it's not going to cost a bomb
leaving it on 24 hours a day, is it? Thanks.
11/06/2012 13:43
Thanks for the replies, I never intended to have the TB unit itself
outside, just in the roof space, which pretty much follows the
temperature of my room anyway, as I only heat it in very cold weather
as the room pretty much follows the temperature of the rest of the
hose.
The stuff arrived this morning, with regard to the antenna, does it
need to see the sky from horizon to horizon? Or would a mount a few
feet above the gutter of the bungalow be adequate? I am not sure how
many satellites it needs to see to work properly. A mount about 3 feet
above the gutter line would be neat and trivial. Thanks again.
--
Best Regards,
Chris Wilson.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.