Re: [time-nuts] GPS antenna installation problem
Two or one tee connectors will allow the cable to exit and reenter. If
your side arm is using a elbow now replace it with a tee.
Thanks, but I don't picture what you are trying to describe.
Are you talking about tees and elbows in the pipe or cable?
I was thinking of the simple case with only a simple vertical pipe to a
single antenna, no side arms.
Maybe the answer is that you can't support the cable in the really simple
case of one vertical pipe with the antenna on top. If you want to support
the cable you have to have some other setup so you can get at the cable.
How about a different question? How much cable can a connector support?
How would I support a cable anyway? I'm thinking of something like a Chinese
finger trap with a string on one end that gets attached to a string. Are
there cable clamp gizmos that are tight enough to grab but loose enough not
to distort the cable and also work over temperature cycling and ...
Is low loss coax stiff enough that I can support it from the bottom and push
it up into a pipe? (I'm assuming the pipe is narrow enough and/or the coax
is stiff enough to hold the coax in place.)
--
These are my opinions, not necessarily my employer's. I hate spam.
a couple of suggestions:
- Use a captive center pin on the N male connector.
for example, Kings Electronics Inc. N male, model # KN-59-176 for RG-214
coaxial cable,
center pin is solder type and captive, will not move axially. Wrench
clamp on the shield.
Kings cage = 91836
mil spec: M39012/01-0005
a few bucks each
- consider adding a foam in place insulation, inside the plastic pipe
to support the coaxial cable.
drill a 1/8" hole every few feet and squirt in the aerosol foam till it
comes out of the hole.
Go for the minimally expanding insulating foam you will find in Home
Depot or Lowes.
Stan, W1LE Fn41sr Cape Cod
Hal Murray wrote:
Two or one tee connectors will allow the cable to exit and reenter. If
your side arm is using a elbow now replace it with a tee.
Thanks, but I don't picture what you are trying to describe.
Are you talking about tees and elbows in the pipe or cable?
How about something like these cable grips?
http://www.deltaelectricproducts.com/
(This is just an example to show what I'm talking about. I'm sure a
local electrical supplier has them.)
You'd have to figure out the cable routing and attachment, but it should
take the strain off the connector. It seems like I saw something on one
of the ham radio supplier sites for coax cable support, but can't find
it now. Not sure if its the same thing.
Alan
Your chinese finger trap supports are available at any reasonably sized
electrical supply house.
Don
----- Original Message -----
From: "Hal Murray" hmurray@megapathdsl.net
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Sunday, March 01, 2009 6:15 PM
Subject: Re: [time-nuts] GPS antenna installation problem
Two or one tee connectors will allow the cable to exit and reenter. If
your side arm is using a elbow now replace it with a tee.
Thanks, but I don't picture what you are trying to describe.
Are you talking about tees and elbows in the pipe or cable?
I was thinking of the simple case with only a simple vertical pipe to a
single antenna, no side arms.
Maybe the answer is that you can't support the cable in the really simple
case of one vertical pipe with the antenna on top. If you want to support
the cable you have to have some other setup so you can get at the cable.
How about a different question? How much cable can a connector support?
How would I support a cable anyway? I'm thinking of something like a
Chinese
finger trap with a string on one end that gets attached to a string. Are
there cable clamp gizmos that are tight enough to grab but loose enough
not
to distort the cable and also work over temperature cycling and ...
Is low loss coax stiff enough that I can support it from the bottom and
push
it up into a pipe? (I'm assuming the pipe is narrow enough and/or the
coax
is stiff enough to hold the coax in place.)
--
These are my opinions, not necessarily my employer's. I hate spam.
time-nuts mailing list -- time-nuts@febo.com
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Group,
Looks like this subject has ended, so I'll summarize:
Bruce Griffiths said the plastic has 12X the expansion coefficient of
copper, so cold alone shouldn't have pulled the center pin. Now I wonder
if the cold contraction pushed the insulation along the core wire and
then pulled the pin when it warmed up. He also mentioned that some ROHS
connections fail due to thermal cycling, but I used antique solder and
wrench-clamp connectors.
Tom Van Baak asked if the signal degraded or was cut off. I don't look
at it all the time, so my first clue was the Holdover light on the
receiver. GPScon gave me the holdover duration, accurate to 999 hours,
then 1000+.
Stan, W1LE, suggested a captive center pin connector, which I will try
in April or May when the snow goes away. Thanks.
Several people said 20 feet unsupported was too long, but I'm not gonna
fill a 10 foot, 6 inch diameter pipe with foam. I'll get some light
chain and individually tie the cables to the chain, then support the
chain above the point where the cables turn into the 2 foot arms. Metric
conversions are left as an exercise for the reader, as they are for me.
Speaking of conversions, I grew up (since 1938) with movie credits that
mentioned the Gaffer (head electrician). Last year I mentored students
building a robot for a FIRST Robotics competition. The carpet on the
field would be marked with red, black, and white gaffer's tape, which we
got in 2 inch width from a theater supply place. Gaffer's tape is
intended to hold down wires running across a set until the show closes.
Where did Gaffa tape come from?
Thanks to all who contributed.
Bill Hawkins
-----Original Message-----
From: Stan W1LE
Sent: Sunday, March 01, 2009 7:56 PM
a couple of suggestions:
- Use a captive center pin on the N male connector.
for example, Kings Electronics Inc. N male, model # KN-59-176 for RG-214
coaxial cable, center pin is solder type and captive, will not move
axially. Wrench clamp on the shield.
Kings cage = 91836
mil spec: M39012/01-0005
a few bucks each
- consider adding a foam in place insulation, inside the plastic pipe
to support the coaxial cable.
drill a 1/8" hole every few feet and squirt in the aerosol foam till it
comes out of the hole.
Go for the minimally expanding insulating foam you will find in Home
Depot or Lowes.
Stan, W1LE Fn41sr Cape Cod
Bill Hawkins wrote:
...
Speaking of conversions, I grew up (since 1938) with movie credits that
mentioned the Gaffer (head electrician). Last year I mentored students
building a robot for a FIRST Robotics competition. The carpet on the
field would be marked with red, black, and white gaffer's tape, which we
got in 2 inch width from a theater supply place. Gaffer's tape is
intended to hold down wires running across a set until the show closes.
Where did Gaffa tape come from?
Probably from the same place as Duck tape.
Human ears trying to make sense out of what they hear.
-Chuck Harris
Actually it is "duct" tape.
Used to air seal the metal joints in a metal duct work system for heat
and AC.
New building codes require a mastic paint be applied over all metal
joints in the duct work system.
I guess it is an energy conservation issue, so the processed air does
not leak into unintended spaces.
Stan,W1LE
Chuck Harris wrote:
Bill Hawkins wrote:
...
Speaking of conversions, I grew up (since 1938) with movie credits that
mentioned the Gaffer (head electrician). Last year I mentored students
building a robot for a FIRST Robotics competition. The carpet on the
field would be marked with red, black, and white gaffer's tape, which we
got in 2 inch width from a theater supply place. Gaffer's tape is
intended to hold down wires running across a set until the show closes.
Where did Gaffa tape come from?
Probably from the same place as Duck tape.
Human ears trying to make sense out of what they hear.
-Chuck Harris
time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.
I know. Did you read my post?
-Chuck Harris
Stan W1LE wrote:
Actually it is "duct" tape.
Used to air seal the metal joints in a metal duct work system for heat
and AC.
New building codes require a mastic paint be applied over all metal
joints in the duct work system.
I guess it is an energy conservation issue, so the processed air does
not leak into unintended spaces.
Stan,W1LE
Chuck Harris wrote:
Bill Hawkins wrote:
...
Speaking of conversions, I grew up (since 1938) with movie credits that
mentioned the Gaffer (head electrician). Last year I mentored students
building a robot for a FIRST Robotics competition. The carpet on the
field would be marked with red, black, and white gaffer's tape, which we
got in 2 inch width from a theater supply place. Gaffer's tape is
intended to hold down wires running across a set until the show closes.
Where did Gaffa tape come from?
Probably from the same place as Duck tape.
Human ears trying to make sense out of what they hear.
-Chuck Harris
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.
In message 49AEF43D.3010103@verizon.net, Stan W1LE writes:
Actually it is "duct" tape.
No it is not.
Duct tape is made to stay stuck and tight on ventilation ducts in
a wide range of temperatures and humidities, it is not meant to
come off again, ever, and if you try, it will leave a sticky band
of adhesive on the substrate. Secondary characteristics is that
it is nonedible for any insect or rodent and I belive: non-flammable.
Gaffer's tape is meant to stay in comparatively benign environmentals,
but only until you want it to come off again, at which time a gentle
but firm pull at the right angle will make it peel off, taking with
it all the adhesive material. Gaffers tape will generally not work
near or below the freezing point, som variants are tolerant of high
temperatures (for spot-lights etc).
If you hold down cables with duct tape during a production in a
building which is a national heritage site, you will never be
allowed through the door again.
If you use gaffer's tape, they will have no reason for complaint.
And yes, it's much more expensive.
Poul-Henning
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
In message 48E1C1775B054C2E9D30E7782A40A7B5@cyrus, "Bill Hawkins" writes:
Several people said 20 feet unsupported was too long, but I'm not gonna
fill a 10 foot, 6 inch diameter pipe with foam. I'll get some light
chain [...]
Over here you can buy a clothes-line which is actually a nylon covered
un-spun steel-wire. I use that for such cableruns because it is easy
to string it up and it stays taught all year. Tie the coax to it with
nylon strips every feet.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.