On Mon, 26 Dec 2011 09:08:00 -0800, Jeff Liebermann wrote:
Total is 175ft. However, I think you're underestimating the "extra"
cable needed at each end for service loops and just plain getting out of
the way of things. Add another 25ft. So, you need 200ft.

Hi Jeff,

You were totally right!

I 'thought' it was a hundred-foot run of the outdoor cable from the
antenna to the house (even allowing for the ten feet of antenna).

First off, I extended the water-pipe antenna to about 16 feet; then I
wrapped the cat5e outdoor cable around the water pipe like a barber shop
pole! (See pic)
http://www5.picturepush.com/photo/a/...mg/7248788.gif

Then, I added about 20 or 30 extra feet for zig zagging in the yard when
I finally bury it in the ground (I'm told we're not allowed to have wires
going to our houses in the air out here).

Then, once inside the house at a convenient spot (see picture below) I
looped an extra few feet of wire.

The total was 224 feet for that one hundred-foot run to the house!
(Luckily the cable is marked every two feet so the antenna end reads
017350 feet while the end in the office reads 017526 feet.)

Here is the sequence showing my 'bright idea' trying to avoid the garage
by sneaking in on an air conditioning pipe!
http://www2.picturepush.com/photo/a/...mg/7248800.gif
http://www4.picturepush.com/photo/a/...mg/7248802.gif
http://www5.picturepush.com/photo/a/...mg/7248803.gif


Likewise, that short run to the game room with tons of extra wire looped
in the crawl space took another 62 feet! (from the 017528 mark to the
017590 mark).

So, you're totally right that it takes way more cable than I thought!

One mistake I made was to buy all outdoor cable. In hind sight, only half
of the cable needed to be the tan outdoor quality. The rest could have
been cheaper indoor plenum (blue) stuff.

On Mon, 26 Dec 2011 09:08:00 -0800, Jeff Liebermann wrote:

I can also scribble on the 2x4 base plate something
about where the wire is going, instead of dealing with wire tags and
labels.

Now I see this!

I havn't had Internet for a day as I had to disassemble everything (to
follow up on everyone's advice here) and re-assemble.

Here is how I labeled the wires:
http://www1.picturepush.com/photo/a/...mg/7248809.gif

But, I like your idea of labeling the woodwork better!

On Mon, 26 Dec 2011 12:23:05 -0600, Char Jackson wrote:
I don't know if it fits your plans, but I like to store that extra loop
of cable inside the wall so it's out of sight until/unless it's needed.
Maybe that's what you meant.

Yes. There are many feet of cable stored inside the crawl space, looped
around and around and around and hanging on a nail in case it's ever
needed.

The bad news is that I've more than doubled my 100 feet (it's now 224
feet from the top of the antenna to the wall plate in the office!).

Here is a picture of what's inside the wall!
(I hadn't expected electricity so close!)
http://www4.picturepush.com/photo/a/...mg/7248832.gif

And, here's the (almost) finished product:
http://www1.picturepush.com/photo/a/...mg/7248834.gif

PS: Nobody mentioned that the wall plates come in three colors of
white!

On Fri, 30 Dec 2011 09:13:53 +0000 (UTC), Chuck Banshee
wrote:

However, only the first 100 feet of my installation actually 'needed' to
be outdoor cable. The rest is indoor.

The stuff I excavated on eBay is not outdoor cable. There are various
flavors of outdoor cable. What I think you have is UV proof but not
not waterproof (gel filled). I can't tell from here and the Comtran
web pile is useless:
http://www.comtrancorp.com

However the problem is not UV protection. Since you're just dumping
the cable on the ground, you're going to punch holes in it every time
someone walks on it. Same with critters chewing on the cable. What
you'll need is UV proof, water proof (gel filled), and armoured. Or,
you can use some form of conduit.

Don't spiral the coax down the mast. When you drop the mast for
maintenance, you leave far too many opportunities to punch holes in
the coax when it hits the ground. Same with leaning a ladder against
the mast for inspection. Also visualize what multiple cables going
down the mast will look like. Run the cables down the BACK side of
the mast and secure with black, UV proof, ty-wraps.

Also, in a previous post, you mentioned other electronics stores in
the SF Bay area. Here's a map,
http://ziiz.co/map
created by Glenn Geller, as posted in ba.internet.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Fri, 30 Dec 2011 09:41:37 +0000 (UTC), Chuck Banshee
wrote:

On Mon, 26 Dec 2011 09:08:00 -0800, Jeff Liebermann wrote:

I can also scribble on the 2x4 base plate something
about where the wire is going, instead of dealing with wire tags and
labels.

Here is how I labeled the wires:
http://www1.picturepush.com/photo/a/...mg/7248809.gif

Well, blue ink on paper, inside a vinyl sleeve will work. The only
problem is that after about 2 years, the blue ink will fade to
invisible ink. I use a proper label maker, vinyl labels, and use
scotch tape to attach to wire. I also don't use such long labels as
bending the wire puts the label under tension, which eventually
breaks. I once labeled a phone closet full for station wire, only to
find a year later that all 25 labels had fallen off.

But, I like your idea of labeling the woodwork better!

Nope. Labeling the 2x4 is for mid span identification. You still
have to label the end points. Labeling the hole is also problematic
if you have more than one cable through it. It's mostly a convenience
when dealing with later rework.

Incidentally, when going between floors, I try to use conduit instead
of just running the wires. Many reasons, but the big one is that
going between floors is more difficult than horizontal runs. Where
there's one cable, there's always a need for more. My own derangement
has about 10 cables crammed into 1" conduit between upstairs and
downstairs.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Fri, 30 Dec 2011 09:24:31 +0000 (UTC), Chuck Banshee
wrote:

It's Hilltop. And it's 802.11, not NV2.

Good.

They're an easy line-of-sight connection at -65 dBm yet the AP is about a
mile or two away (hard to tell just by looking). (I always wondered if
the ACK information in the radio is accurate for telling me how far the
AP is actually away from me?)

No, it's not even close. Flight time (speed of light) is about 1ft
per nanosecond. A mile would be about 6 microseconds. The best
resolution you could get with ping is perhaps 0.1 millisecond. Most
of the ping delay is in the CPU and attendent IP stack in the router.

Here's my water-pipe antenna, simply stuck into an existing hole in the
ground!
http://www5.picturepush.com/photo/a/...mg/7248778.gif

Here's a spare time math problem. Calculate the area of the antenna.
Estimate your maximum local wind speed. Calculate the wind load on
the antenna and the mast. Tie a rope to the antenna and pull with the
calculated wind load. If the mast falls over, find some guy wires or
ropes.
http://k7nv.com/notebook/topics/windload.html
I can't tell from here how deep the mast extends into the ground, how
much concrete is in the hole, or soil conditions.

So the only firewall is the broadband router.

Good. That should work better than double NAT.

Here's a picture of the antenna and radio (set up as a bridge) on the
ground:
http://www1.picturepush.com/photo/a/...mg/7248774.gif

See the 4 screws securing the bracket to the antenna? If the pipe
hits the coax connector and radio, then simply unscrew the bracket,
rotate 180 degrees, re-attach, and you have an offset mount. Having
the antenna mounted unsymmetrically may seem a bit odd, but it should
work.

Also, verify whether you're vertically or horizontally polarized. No
clue what Hilltop is using, but it should be the same. Mounting it at
a 45 degree angle, as in a previous photo, will work, but not very
well.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Fri, 30 Dec 2011 09:38:01 +0000 (UTC), Chuck Banshee
wrote:

On Mon, 26 Dec 2011 09:08:00 -0800, Jeff Liebermann wrote:
Total is 175ft. However, I think you're underestimating the "extra"
cable needed at each end for service loops and just plain getting out of
the way of things. Add another 25ft. So, you need 200ft.

Hi Jeff,

You were totally right!

I'm always right (except when I'm wrong). I have a roll of nylon
twine, that I've marked every 10ft, that I use for estimating cable
runs (and also as a pull line). The numbers on the cable jacket are
handy for calculating if there's enough cable left in the box to do
the job.

One mistake I made was to buy all outdoor cable. In hind sight, only half
of the cable needed to be the tan outdoor quality. The rest could have
been cheaper indoor plenum (blue) stuff.

Neither is suitable if you're just dumping it on the ground. What you
want is direct burial cable, preferably gel filled, and possibly
armored. That's not cheap, but you only will need about 175 ft of it.
You won't find that at Home Despot, but might find it at an electrical
supply house. However, eBay is cheaper:
http://www.ebay.com/itm/380254910507
http://www.ebay.com/itm/190582159449
About $150/1000ft. Watch out for shipping charges. The stuff is
heavy. Notice the flakey white stuff on the wires. That's the gel. I
hate the stuff.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Fri, 30 Dec 2011 09:54:32 +0000 (UTC), Chuck Banshee
wrote:

On Mon, 26 Dec 2011 12:23:05 -0600, Char Jackson wrote:
I don't know if it fits your plans, but I like to store that extra loop
of cable inside the wall so it's out of sight until/unless it's needed.
Maybe that's what you meant.

Yes. There are many feet of cable stored inside the crawl space, looped
around and around and around and hanging on a nail in case it's ever
needed.

I wonder what the pros will say about all that extra cable. I normally
leave a single loop, maybe 12-18 inches, so that I can reterminate the
end if a connection fails. I don't know what the 'best practices' are.

On Fri, 30 Dec 2011 09:03:27 +0000 (UTC), Chuck Banshee
wrote:

On Mon, 26 Dec 2011 22:38:06 -0600, Char Jackson wrote:
Given that scenario, there are no addressing conflicts, but you won't be
able to reach the LAN interface of the modem because there's a router
between you and the modem.

I wonder what would explain how I can connect to the broadband router's
web page (eg 192.168.1.1) and to the radio on top of the antenna (eg
10.100.0.1) from the same wireless laptop inside the house.

I can connect to both - but since the laptop is 192.168.1.(something), by
all rights, it should only connect to the broadband router (which is on
the same subnet).

How it still can connect to the antenna radio (which is on a wholly
different subnet) is beyond my understanding.

I assume you're able to connect to the WISP radio via your broadband
router. That's what routers do, they act as an interface between two
or more networks.

BTW, here's a daylight picture of the antenna wiring.

What do you guys do to secure wires when you go down an antenna?
http://www2.picturepush.com/photo/a/...mg/7248680.gif

That doesn't look quite as good as I'd hoped. Just thinking out loud,
I wonder if you'd get more stability, more protection from the
elements, and more protection from general damage by putting the
vertical run inside a small conduit, and solidly attaching the conduit
to the pole.

On Fri, 30 Dec 2011 07:49:25 +0000 (UTC), Chuck Banshee
wrote:

On Mon, 26 Dec 2011 18:29:46 -0500, zzzzzzzzzz wrote:
Don't forget the door Nazis. ...and the poor prices.

Sorry I haven't responded. My entire setup was a dismal failure until
just now (more about that, with pics, later).

As for Frys, I hadn't realized they were in more places than just the
Silicon Valley. Thanks for the update.

And, you're right. The prices are 'just ok'. Nothing special.

Less than "OK"; no better than Best Buy.

The big deal for Frys (no, I don't work for them) is the availability of
whatever you need (for the most part). Of course, their antenna selection
sucked when I tried to buy there (I ended up buying from Streakwave in
San Jose instead).

A lot of junk. If you want top-shelf stuff, don't go to Frys. Again, I go
there once in a while but almost always leave empty-handed.

As for those door nazis, they're better than those at costco. They will
NEVER stop you if you just walk past them. They're told to just let you
go (after all, it's YOUR stuff you just bought). However, try that trick
at Costco and the manager will chase you into the parking lot (ask me how
I know).

You've *agreed* to submit to Costco's door nazis, not so for Frys'. I did
have one threaten me, though it was over a decade back (in Silly Valley).

On Fri, 30 Dec 2011 09:03:28 -0800, Jeff Liebermann
wrote:

Here's a picture of the antenna and radio (set up as a bridge) on the
ground:
http://www1.picturepush.com/photo/a/...mg/7248774.gif

See the 4 screws securing the bracket to the antenna? If the pipe
hits the coax connector and radio, then simply unscrew the bracket,
rotate 180 degrees, re-attach, and you have an offset mount. Having
the antenna mounted unsymmetrically may seem a bit odd, but it should
work.

Duh... or, you could just add a right angle Type-N connector and just
move the radio out of the way.
http://cfnewsads.thomasnet.com/images/large/559/559510.jpg
http://www.ebay.com/itm/150658853306
I have a few if you're in a hurry (i.e. before it rains).

Also:
http://www5.picturepush.com/photo/a/7248788/img/7248788.gif
That doesn't look like it has much concrete in the ground. It's
probably just fine when the ground is dry, but I hate to see what will
happen when the ground gets wet, and the nearby tree branches start
wacking the pole around. It's not going to fall over, but it might
move around enough to loose the path:
http://www5.picturepush.com/photo/a/7248778/img/7248778.gif
Hmmm... are you sure the pipe is 16ft long? Judging by the height of
the nearby picnic table (about 30" high), the mast looks like it's
about 25ft high.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Fri, 30 Dec 2011 12:24:37 -0800, Jeff Liebermann
wrote:

http://www5.picturepush.com/photo/a/7248778/img/7248778.gif
Hmmm... are you sure the pipe is 16ft long? Judging by the height of
the nearby picnic table (about 30" high), the mast looks like it's
about 25ft high.

Ummm... make that about 31ft:
http://802.11junk.com/jeffl/crud/mast.jpg
Perhaps that might explain why you consumed so much CAT5?

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Fri, 30 Dec 2011 11:26:57 -0600, Char Jackson wrote:
That doesn't look quite as good as I'd hoped.

When I look back at it, it 'does' look a little shoddy just wrapped
around the pole like a barber-shop twist.

putting the vertical run inside a small conduit,
and solidly attaching the conduit to the pole.

That's a GREAT IDEA!

I could also, I guess, put the wire INSIDE the water pipe mast but I like
the idea of strapping PVC conduit to the pole, alongside the pole, with
the wire running down.

PS: I wish I thought of that 'before' I did it - but this suggestion will
help others and I can do it in my retrofit when I add the TV antenna!

On Fri, 30 Dec 2011 12:28:24 -0500, zzzzzzzzzz wrote:
You've *agreed* to submit to Costco's door nazis, not so for Frys'. I
did have one threaten me, though it was over a decade back (in Silly
Valley).

I think you're exactly right!

The way the Frys manager told me when I asked him about it was that it's
a courtesy to check your receipt to make sure you get what you paid for
(yeah, right).

He was the one who told me that you do not have to show your receipt and
they won't stop you.

Looking it up, I wonder if it's some kind of illegal search & seizure
thing ... where they need to have reasonable cause or something. It's not
the government so I'm not sure (and I'm not a lawyer).

On the other hand, when I bought just one thing at Costco (yeah, I
know ... the lines ... but I needed it), I didn't want to wait on the
long line at the door to leave ... so I just walked through the middle of
the two lines.

Guess what?

I got to my car, and I had already closed the trunk when the manager
caught up to me (probably called by the Costco door nazis). She asked to
see inside my trunk.

At this point, I 'could' have put up a fuss - but - I just opened it and
let her see it and check it against my receipt.

When I asked her, she said the same thing Frys did. They want to make
sure didn't get overcharged.

I believed her as much as I believed the Frys manager.

The takeaway is this:
- You don't have to show your receipt at the Frys exit;
- But you do (sort of) have to show it at Costco.

On Fri, 30 Dec 2011 09:03:28 -0800, Jeff Liebermann wrote:

I can't tell from here how deep the mast extends into the ground,
how much concrete is in the hole, or soil conditions.

Hi Jeff,

My mistake for not providing useful data.

The hole goes 3 feet down inside a steel pipe sunk in the concrete (see
pictures below). The soil is not like yours as you're on the western side
of the fault line. You have topsoil on top of Gabrilan granite (the
Salinian block).

I have highly deformed & easily broken up chert on the eastern side of
the fault line, formed in the bottom of the Pacific Ocean when my side of
the San Andreas fault was the edge of the continent.

I'd better run the calculations you suggested & report back.

Here are some pictures of the concrete & steel setup:

1. This is the existing hole in the ground:
http://www5.picturepush.com/photo/a/...40/7253378.gif

2. This is my ingenious (perhaps ludicrous) attempt at fitting a two-inch
pipe in a 3.5 inch hole!
http://www1.picturepush.com/photo/a/...mg/7253389.gif

3. I modified a plastic 3 inch to 2 inch conduit bushing (removing the
lip with a Dremel tool) as shown he
http://www5.picturepush.com/photo/a/...mg/7253403.gif

4. I listened to the suggestion to use anti-seize on the threading:
http://www2.picturepush.com/photo/a/...mg/7253415.gif

5. Then I took 2 inch and 1.5 inch water pipe and strung them together:
http://www5.picturepush.com/photo/a/...mg/7253408.gif

6. Being all alone, holding pipe free to twist on threads was easier said
than done:
http://www5.picturepush.com/photo/a/...mg/7253413.gif

7. Then I shoved the whole contraption 3 feet into the existing ground
hole:
http://www2.picturepush.com/photo/a/...mg/7253440.gif

8. The bottom length is about six feet of 2 inch water pipe:
http://www3.picturepush.com/photo/a/...mg/7253451.gif

9. The top of the antenna is about 16 feet up:
http://www2.picturepush.com/photo/a/...mg/7253460.gif

Picture #7 above is the key problem.

I don't know if the plastic bushing will hold up (I wish I could have
found a steel 3" to 2" adapter). Plus it's only at the top (with the
bottom of the pipe three feet below able to wobble).

With no wind, it's sturdy - but winds easily top 120mph out here (more
sometimes) so that might be a problem.

Here's the height:
- About 6 feet of 2" threaded water pipe stuck about 3' into the ground.
- A 10 foot length of 1.5 inch threaded water pipe
- A 2 foot length of 1.5 inch threaded water pipe
- Then antenna is about a foot square (give or take)

I'll do the calculations on the web site you suggested to find the loads.

On Fri, 30 Dec 2011 12:24:37 -0800, Jeff Liebermann wrote:

simply unscrew the bracket, rotate 180 degrees, re-attach,
and you have an offset mount. Having the antenna mounted
unsymmetrically may seem a bit odd, but it should work.

Duh... or, you could just add a right angle Type-N connector

Hi Jeff,

smacks head For some reason, it didn't occur to me that you 'can'
rotate the antenna mount.

I think the reason is that my old antenna mount was a three-hole affair,
which can NOT be rotated - so - for some inane reason, I didn't even
'think' that I could with this four-hole antenna mount. My mistake.

On Fri, 30 Dec 2011 12:24:37 -0800, Jeff Liebermann wrote:

Hmmm... are you sure the pipe is 16ft long? Judging by the height of
the nearby picnic table (about 30" high), the mast looks like it's about
25ft high.

I think I was a bit overzealous on the height of the mast.

Technically, it only needed about 10 or 12 feet above ground to clear the
lower bush just in front of the antenna.

I just measured it:
- 42 inches from concrete to the top of the 2"-to-1.5" reducer (3.5 feet)
- 10 feet of 1.5" pipe
- 2 feet of 1.5" pipe

So the total length +- 1/2 foot above ground is about 15.5 feet.

In hind sight, I probably should have gotten a shorter 2" pipe which just
made it to the top of the concrete. That way, I could unscrew the antenna
instead of lifting it out of the ground to service. (I don't have yet an
orchard ladder, which is what I really need to trim those scrub oak and
bay laurel trees!)

On Fri, 30 Dec 2011 12:35:17 -0800, Jeff Liebermann wrote:
Perhaps that might explain why you consumed so much CAT5?

Hi Jeff,

I appreciate the calculations.

You even made ME wonder if I had bought a 20 foot pipe instead of 10 feet!

It turns out that the table, because it's far away from the mast, looks
deceptively small.

Here is a shot with a 3-foot yardstick and a 2-foot square next to the
mast:
http://www3.picturepush.com/photo/a/...mg/7254016.gif

Here is that same shot but I moved back to where the original picture was
taken:
http://www4.picturepush.com/photo/a/...mg/7254017.gif


The picnic table looks deceptively small. I'm not sure why but it must
have something to do with the angles or distance.

The antenna looks to be about 15.5 feet above ground (give or take a half
foot for couplings and mounts). And it's about 3 feet into the ground.

I 'could' dig it deeper if I need to as I have plenty of height.

I do agree with you - that it's still too tall (I guess I should take off
the two-foot section on top). I only put it there because I bought it for
the TV antenna but I'm not sure if I can get 'any' signal pointing
southwest in the Santa Cruz mountains.

On Fri, 30 Dec 2011 08:43:22 -0800, Jeff Liebermann wrote:
What I think you have is UV proof but not not waterproof (gel filled).

I agree.

What you'll need is UV proof, water proof (gel filled),
and armoured. Or, you can use some form of conduit.

Conduit is what I'll use then.

Run the cables down the BACK side of the mast and
secure with black, UV proof, ty-wraps.

OK. The logic (once I know it) is impeccable. Will do.

Here's a map,
http://ziiz.co/map

Wow. Very nice. I didn't know about lots of them, for example, HomeTech
Solutions off of DeAnza. Wow. More than I ever knew. Lots better than
Home Depot!

On Fri, 30 Dec 2011 08:52:49 -0800, Jeff Liebermann wrote:

Incidentally, when going between floors, I try to use conduit instead of
just running the wires. Many reasons

In hindsight, since that was 5 feet of drilling (most of it air, of
course), between floors, conduit would have been a good idea.

That's good advice for next time!

On Fri, 30 Dec 2011 21:23:31 +0000 (UTC), Chuck Banshee
wrote:

On Fri, 30 Dec 2011 11:26:57 -0600, Char Jackson wrote:
That doesn't look quite as good as I'd hoped.

When I look back at it, it 'does' look a little shoddy just wrapped
around the pole like a barber-shop twist.

putting the vertical run inside a small conduit,
and solidly attaching the conduit to the pole.

That's a GREAT IDEA!

I could also, I guess, put the wire INSIDE the water pipe mast but I like
the idea of strapping PVC conduit to the pole, alongside the pole, with
the wire running down.

PS: I wish I thought of that 'before' I did it - but this suggestion will
help others and I can do it in my retrofit when I add the TV antenna!

Hopefully, someone who's done it will weigh in before it's officially
declared a good idea. I suppose you'd cap the top of the conduit to
keep most of the water and some of the critters out, or use two 90
degree fittings so that the Ethernet cable enters the conduit going
up, over, and then down the length of the pole. Or something like
that.

On Fri, 30 Dec 2011 19:32:46 -0600, Char Jackson
wrote:

Hopefully, someone who's done it will weigh in before it's officially
declared a good idea. I suppose you'd cap the top of the conduit to
keep most of the water and some of the critters out, or use two 90
degree fittings so that the Ethernet cable enters the conduit going
up, over, and then down the length of the pole. Or something like
that.

Argh. I've never seen it done by running the cables through the mast,
even with a tilt up mast derrangement.
http://www.floatograph.com/rmmast/
http://www.solarwheel.co.uk/tilt-up.php
http://members.westnet.com.au/page3/tilt_over_tower.htm
http://www.photomast.ca/Bulletin_Board/Trailer.jpg

Drivel: This isn't a tilt over mast, but is kinda cool for keeping
the antennas from digging a hole in the ground when lowered.
http://nn4zz.com/tiltplate.htm

However, running coax up the center of a monopole for cellular service
is standard procedure. The differnce is that the monopole is MUCH
larger than the suggested water pipe mast. This offers easier access,
additional support points, and less of a mess. Monopoles do have
their problems, as these links illustrate:
http://802.11junk.com/jeffl/SCCARC-talk-2010-06-18/Burning-Towers.htm

The problems with running wires down the center of a mast are not very
obvious:
1. The top of the mast looked like a coax "fountain" with all the
cables dripping out of the top in all directions. It was truely ugly.
2. There is no way to secure the cables except at the top of the
mast. The entire weight of the coax is supported only at the top. I
would have expected the cables to stretch slightly. Instead, the
sharp turn made by the coax cables going out the top caused the center
conductor to cold flow through the dielectric, eventually shorting the
cable.
3. If the mast is tilt over, as is quite common, the cable out the
bottom has to include a rather lenthy service loop. If you're going
to secure it short pipe stub, you run the risk of cutting the cable if
you lower the mast to the ground.

Bottom line: Lousy idea.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com
# http://www.LearnByDestroying.com AE6KS

On Fri, 30 Dec 2011 18:16:45 -0800, Jeff Liebermann
wrote:

On Fri, 30 Dec 2011 19:32:46 -0600, Char Jackson
wrote:

Hopefully, someone who's done it will weigh in before it's officially
declared a good idea. I suppose you'd cap the top of the conduit to
keep most of the water and some of the critters out, or use two 90
degree fittings so that the Ethernet cable enters the conduit going
up, over, and then down the length of the pole. Or something like
that.

Argh. I've never seen it done by running the cables through the mast,

snip We were talking about a vertical conduit, not the mast.

The problems with running wires down the center of a mast are not very
obvious:
1. The top of the mast looked like a coax "fountain" with all the
cables dripping out of the top in all directions. It was truely ugly.

Single Ethernet cable in this case. When taken in context with the
looks of the concrete base and the overall appearance of a water pipe
mast, the level of beauty is not out of line.

2. There is no way to secure the cables except at the top of the
mast. The entire weight of the coax is supported only at the top. I
would have expected the cables to stretch slightly. Instead, the
sharp turn made by the coax cables going out the top caused the center
conductor to cold flow through the dielectric, eventually shorting the
cable.

Yes, there are ways to secure the cable but they haven't been
discussed.

3. If the mast is tilt over, as is quite common, the cable out the
bottom has to include a rather lenthy service loop. If you're going
to secure it short pipe stub, you run the risk of cutting the cable if
you lower the mast to the ground.

I haven't heard of any plans to tilt this mast.

Bottom line: Lousy idea.

You're probably right, even though each of your objections doesn't
actually apply in this case.

On Fri, 30 Dec 2011 22:02:57 +0000 (UTC), Chuck Banshee
wrote:

On Fri, 30 Dec 2011 12:28:24 -0500, zzzzzzzzzz wrote:
You've *agreed* to submit to Costco's door nazis, not so for Frys'. I
did have one threaten me, though it was over a decade back (in Silly
Valley).

I think you're exactly right!

Of course. ;-)

The way the Frys manager told me when I asked him about it was that it's
a courtesy to check your receipt to make sure you get what you paid for
(yeah, right).

What, you don't believe him? That's probably what he was told by his boss.

He was the one who told me that you do not have to show your receipt and
they won't stop you.

Sure. It's illegal. Once the money has changed hands, it's yours. If he
detains you, it's kidnapping. ;-)

Looking it up, I wonder if it's some kind of illegal search & seizure
thing ... where they need to have reasonable cause or something. It's not
the government so I'm not sure (and I'm not a lawyer).

No, not illegal search, rather he doesn't authority to arrest you and has no
probable cause if he did. If he detains you, against your will, it's false
imprisonment. He's the one who will visit the Gray Bar Hotel.

On the other hand, when I bought just one thing at Costco (yeah, I
know ... the lines ... but I needed it), I didn't want to wait on the
long line at the door to leave ... so I just walked through the middle of
the two lines.

Guess what?

I got to my car, and I had already closed the trunk when the manager
caught up to me (probably called by the Costco door nazis). She asked to
see inside my trunk.

At this point, I 'could' have put up a fuss - but - I just opened it and
let her see it and check it against my receipt.

Right. When you joined Costco, you gave them the right to search your
packages. If you refuse, there isn't much they can do but cancel your
membership, though.

When I asked her, she said the same thing Frys did. They want to make
sure didn't get overcharged.

I believed her as much as I believed the Frys manager.

You're just not the believing type. I can tell. ;-)

The takeaway is this:
- You don't have to show your receipt at the Frys exit;
- But you do (sort of) have to show it at Costco.

You don't "have to" at Costco, either. You agreed to it, though.

On 12/30/2011 12:24 PM, Jeff Liebermann wrote:
On Fri, 30 Dec 2011 09:03:28 -0800, Jeff
wrote:

Here's a picture of the antenna and radio (set up as a bridge) on the
ground:
http://www1.picturepush.com/photo/a/...mg/7248774.gif

See the 4 screws securing the bracket to the antenna? If the pipe
hits the coax connector and radio, then simply unscrew the bracket,
rotate 180 degrees, re-attach, and you have an offset mount. Having
the antenna mounted unsymmetrically may seem a bit odd, but it should
work.

Duh... or, you could just add a right angle Type-N connector and just
move the radio out of the way.
http://cfnewsads.thomasnet.com/images/large/559/559510.jpg
http://www.ebay.com/itm/150658853306
I have a few if you're in a hurry (i.e. before it rains).

Also:
http://www5.picturepush.com/photo/a/7248788/img/7248788.gif
That doesn't look like it has much concrete in the ground. It's
probably just fine when the ground is dry, but I hate to see what will
happen when the ground gets wet, and the nearby tree branches start
wacking the pole around. It's not going to fall over, but it might
move around enough to loose the path:
http://www5.picturepush.com/photo/a/7248778/img/7248778.gif
Hmmm... are you sure the pipe is 16ft long? Judging by the height of
the nearby picnic table (about 30" high), the mast looks like it's
about 25ft high.


I really recommend the right angle N. It makes it far less likely to
break the wifi adapter. Incidentally, ALfa has a similar device called
the tube.

On Sat, 31 Dec 2011 17:25:52 -0800, miso wrote:
I really recommend the right angle N. It makes it far less likely to
break the wifi adapter. Incidentally, ALfa has a similar device called
the tube.

Good point as the Bullet M2 is a cantilevered arm with all the force
concentrated at the attachment point.

But, wouldn't a short N-female-to-N-male pigtail be even better (with the
bullet tie-wrapped to the mast, for example)?

On Sun, 1 Jan 2012 01:55:41 +0000 (UTC), Chuck Banshee
wrote:

But, wouldn't a short N-female-to-N-male pigtail be even better (with the
bullet tie-wrapped to the mast, for example)?

About the same as far as RF loss is concerned. Much worse if you
consider water incursion. If you wrap the right angle connector,
there will be no movement to break the waterproofing seal. However,
with a pigtail, unless the M2 is properly secured to the panel
antenna, it's gonna leak. If you're really careful to use a drip loop
and plenty of slack, you might be able to secure the M2 to the mast,
but I think the first time you move the mast, you're going to loose
the seal.

Incidentally, my method of waterproofing is to mummify the connector
using 1/2" or preferably 1" teflon pipe wrap. On top of that, apply a
layer of 3M Scotch 33+ 7 mil electrical tape. All it does is hold the
teflon tape in place. Spray with a thin coat of clear Krylon spray to
make it UV proof.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 12/31/2011 6:36 PM, Jeff Liebermann wrote:
On Sun, 1 Jan 2012 01:55:41 +0000 (UTC), Chuck Banshee
wrote:

But, wouldn't a short N-female-to-N-male pigtail be even better (with the
bullet tie-wrapped to the mast, for example)?

About the same as far as RF loss is concerned. Much worse if you
consider water incursion. If you wrap the right angle connector,
there will be no movement to break the waterproofing seal. However,
with a pigtail, unless the M2 is properly secured to the panel
antenna, it's gonna leak. If you're really careful to use a drip loop
and plenty of slack, you might be able to secure the M2 to the mast,
but I think the first time you move the mast, you're going to loose
the seal.

Incidentally, my method of waterproofing is to mummify the connector
using 1/2" or preferably 1" teflon pipe wrap. On top of that, apply a
layer of 3M Scotch 33+ 7 mil electrical tape. All it does is hold the
teflon tape in place. Spray with a thin coat of clear Krylon spray to
make it UV proof.


I had a temporary setup that got blown down by the wind. It was the one
time I didn't use a pigtail. It smashed the Alfa 036H. The PCB has a
bulge under the RPSMA connector. It also smells bad when powered up. I
suspect it draws more than the allowed half an amp off the usb bus
because the notebook was very unhappy booting up with the damaged unit
attached.

I got the tube version. It is about $10 extra. No adapter required, i.e.
it goes right to a N connector. [Like when did that become legal?] I use
the elbow. I may mount the "tube" in a metal box just to make it more
rugged. I find the tube version is slightly more sensitive than the 036H
that Alfa sells. Not a big difference, but a step in the right direction.

http://www.youtube.com/watch?v=T-hduzWv5Dw

It comes with a heavy usb cable of the "extension" flavor. I have a few
real watertight feedthroughs I've got from junked NEMA boxes. I don't
think the scheme alfa uses is really watertight on the USB side.

Anyway, a pigtail is probably more likely to fail than a right angle
connector.

I don't suggest people purchase antennas with pigtails on them. That
seems like a design destined to fail.

Photomast looks real Rube Goldberg. Just how expensive is a news van
with telescoping mast?

In the photomast wmv file, it looks like they get it tilted up just in
time before a car go barreling by.

My recollection is there are military antennas where the mast is the
coax, so to speak. That is, support and RF feed are one item.

In any outdoor design, there is the school of "weep hole", and the
school of watertight. Some people claim sealed units really aren't
sealed, so whatever water does get in will eventually do damage. Hence
they come up with a weep hole. The other school of thought is to seal
everything up like a drum.

I bought an old NEMA box, which in theory is sealed, but noticed they
stuffed it with desiccant packs.

Back to CAT5, I notice Moto Canopy setups leave the data cable exposed.

Come to think of it, I've seen some satellite hookups where the coax is
in the LNB(F) support arm.

On Mon, 02 Jan 2012 20:51:18 -0800, miso wrote:

Photomast looks real Rube Goldberg. Just how expensive is a news van
with telescoping mast?

Dunno. Here's the MCI MMDS site survey van circa 2001:
http://802.11junk.com/jeffl/crud/Van-tower.jpg
I think it lasted about a week before it fell over.

In any outdoor design, there is the school of "weep hole", and the
school of watertight. Some people claim sealed units really aren't
sealed, so whatever water does get in will eventually do damage. Hence
they come up with a weep hole. The other school of thought is to seal
everything up like a drum.

I'm in the weep hole skool. My logic is that the only effective water
seal is a pressurized box. Anything less will eventually leak water.
So, unless it's hermetically sealed, and dry air pressurized, it needs
a drain hole.

Back to CAT5, I notice Moto Canopy setups leave the data cable exposed.

Yep. As long as the connector drains water out of the package, it
will work. Gold on gold connectors won't rot. Maybe do it like the
telcos and smear some silicon grease into the connector. Seems to
work for the outdoor POTS NIU.

Come to think of it, I've seen some satellite hookups where the coax is
in the LNB(F) support arm.

Yep. All of mine. The compression style F connector is a good water
seal. (Note: Not all F connectors are suitable for outdoor use).


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann" wrote in message
...
On Mon, 02 Jan 2012 20:51:18 -0800, miso wrote:

Photomast looks real Rube Goldberg. Just how expensive is a news van
with telescoping mast?

Dunno. Here's the MCI MMDS site survey van circa 2001:
http://802.11junk.com/jeffl/crud/Van-tower.jpg
I think it lasted about a week before it fell over.

In any outdoor design, there is the school of "weep hole", and the
school of watertight. Some people claim sealed units really aren't
sealed, so whatever water does get in will eventually do damage. Hence
they come up with a weep hole. The other school of thought is to seal
everything up like a drum.

I'm in the weep hole skool. My logic is that the only effective water
seal is a pressurized box. Anything less will eventually leak water.
So, unless it's hermetically sealed, and dry air pressurized, it needs
a drain hole.

Back to CAT5, I notice Moto Canopy setups leave the data cable exposed.

Yep. As long as the connector drains water out of the package, it
will work. Gold on gold connectors won't rot. Maybe do it like the
telcos and smear some silicon grease into the connector. Seems to
work for the outdoor POTS NIU.

Come to think of it, I've seen some satellite hookups where the coax is
in the LNB(F) support arm.

Yep. All of mine. The compression style F connector is a good water
seal. (Note: Not all F connectors are suitable for outdoor use).


Marine boxes are sealed and do a good job. We'd add a block of camphor
before we closed them up and over near 40 years of working off shore never
had a box leak (save ones that were mechanically damaged)

On 1/3/2012 12:49 AM, NotMe wrote:
"Jeff wrote in message
...
On Mon, 02 Jan 2012 20:51:18 -0800, wrote:

Photomast looks real Rube Goldberg. Just how expensive is a news van
with telescoping mast?

Dunno. Here's the MCI MMDS site survey van circa 2001:
http://802.11junk.com/jeffl/crud/Van-tower.jpg
I think it lasted about a week before it fell over.

In any outdoor design, there is the school of "weep hole", and the
school of watertight. Some people claim sealed units really aren't
sealed, so whatever water does get in will eventually do damage. Hence
they come up with a weep hole. The other school of thought is to seal
everything up like a drum.

I'm in the weep hole skool. My logic is that the only effective water
seal is a pressurized box. Anything less will eventually leak water.
So, unless it's hermetically sealed, and dry air pressurized, it needs
a drain hole.

Back to CAT5, I notice Moto Canopy setups leave the data cable exposed.

Yep. As long as the connector drains water out of the package, it
will work. Gold on gold connectors won't rot. Maybe do it like the
telcos and smear some silicon grease into the connector. Seems to
work for the outdoor POTS NIU.

Come to think of it, I've seen some satellite hookups where the coax is
in the LNB(F) support arm.

Yep. All of mine. The compression style F connector is a good water
seal. (Note: Not all F connectors are suitable for outdoor use).


Marine boxes are sealed and do a good job. We'd add a block of camphor
before we closed them up and over near 40 years of working off shore never
had a box leak (save ones that were mechanically damaged)



I suspect Jeff is closer to reality, though I don't doubt your boxes
didn't leak. For electronics, just moisture in the air is enough. You
would probably need a nitrogen purge and pressurization scheme for
electronics. Some camera housings work that way.

Camphor fumes are to reduce rust. I don't know the chemistry behind
this, so I don't know how effective this scheme is for electronics.

A weep hole doesn't keep out salt.

Fry's has the satellite F connectors. I'm not really impressed with the
satellite coax they sell, though I use their patch cables for temporary
setups.

Quad shielded coax has been at buzzword status for a while. Almost like
drop forged. [Yeah, we dropped that wrench before shipping it to Harbor
Freight.] Yeah, there are four shields. Not the greatest shields.....

On Tue, 03 Jan 2012 12:30:00 -0800, miso wrote:

I suspect Jeff is closer to reality, though I don't doubt your boxes
didn't leak. For electronics, just moisture in the air is enough. You
would probably need a nitrogen purge and pressurization scheme for
electronics. Some camera housings work that way.

Not nitrogen. Too expensive. Just dry air will work.

In a past life, I designed marine radios for Intech Inc. We learned
quite a bit about water proofing. Much of it was learned the hard
way. Most of my radios would work after the boards were soaked with a
bucket of water. There's no magic there, just use low impedances for
literally everything and fairly wide trace spacing. However, I had to
also deal with vendor supplied SCADA hardware, which was full of dense
PCB layout, high impedances, RF sensitive design, and other
nightmares. Kinda like what you find in the typical consumer grade
wireless router. The decision was made to not modify the design, but
rather to protect the sensitive SCADA boards. I won't go into all the
things that didn't work, but I will say that the only thing that
worked every time was a pressurized box, vertically mounted boards (so
that they drain) and dry air. To prevent condensation in case the dry
air went away, there was a small heater to keep the temperature above
the dew point. My idea of dry air was a bicycle pump with an air
compressor dryer filter attached. Add a gauge, a desiccant cartridge,
and the usual warning labels. If you think you can do better with
other technology, you're welcome to try.

Camphor fumes are to reduce rust. I don't know the chemistry behind
this, so I don't know how effective this scheme is for electronics.

Dunno. Most of my stuff was aluminum. There are products that you
can insert inside aluminum tubing (such as for hang gliders and
antennas) that prevent internal corrosion. I don't know the chemistry
offhand.

A weep hole doesn't keep out salt.

Actually, a weep hole has its place. If you can't pressurize with dry
air, then you have to find a place for the water to escape. Water
will eventually evaporate in temperate climates making a weep hole
functional. However, puddling is very bad. That's why I mound the
boards vertically (so they drain).

The absolute worst idea is somewhat sealed box, that's not
pressurized. It works like a water pump. Water collects on the box
seams. The sun comes up, heats up the box, causing some of the inside
air to leak out. The sun goes down, the box cools off, and a partial
vacuum is created inside the box. This sucks the water sitting on the
seams into the box. The next day, the process is repeated.
Eventually, there's quite a bit of water inside the box. It doesn't
just sit on the bottom of the box. It evaporates when warm and
condenses on the electronics. It's MUCH better if the water drain out
the bottom after every cycle instead of being trapped inside.

Fry's has the satellite F connectors. I'm not really impressed with the
satellite coax they sell, though I use their patch cables for temporary
setups.

I make my own CATV cables. The compression type of F connector is
quite waterproof. I've also used it at 2.4Ghz. Works fine. You'll
never notice the 50/75 ohm mismatch as the reflections are all lost in
the high cable losses.
http://www.qsl.net/n9zia/wireless/75_ohm_hardline.html

Quad shielded coax has been at buzzword status for a while. Almost like
drop forged. [Yeah, we dropped that wrench before shipping it to Harbor
Freight.] Yeah, there are four shields. Not the greatest shields.....

Quad shielded exists only because the FCC demanded that CATV leakage
be very very very very low. The only thing that does that is quad
shielded. If you have an ingress problem, use quad. Otherwise,
double shielded (foil + braid) works just fine. My most irritating
problem with RG6a/u is the unplated copper center conductor. It like
to corrode, especially when the mating connector has tin plated
contacts. I've been experimenting with electroless silver plating the
copper, which seems to help.

Archived notes on corrosion by a real expert (not me).
http://yarchive.net/electr/galvanic_corrosion.html
Worth reading methinks.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

I suspect the old Beldin foil plus braid is better than made in China
quad-shield. Yes, quad is more about leakage than "infiltration".

I didn't want to go into this because it gets complicated, but I buy dry
air from scuba shops. You need your own tank. Air is cheap. Inspections
are not. Tank, hose, regulator and the nozzle set me back $50. When I
blow the dust of out something, I don't hit it with refrigerant, which
is what canned air does.

The tax laws regarding buying compressed air are interesting in a
bizarre way, not that it makes much of a difference in price. If they
compress the air at the shop, that is a service, and it has one tax
rule. If they get a big tank of compressed air and use it to fill your
tank, it is stored inventory, and the tax rule is different.

I have no idea what it takes to keep nitrogen at home. I'd have to
research where to buy it. The only nitrogen I ever used was bought by
some corporation and it was the mad scientist liquid type. All that
said, since nitrogen isn't being used in life support like scuba air, I
think it would be relatively cheap.

NEMA with desiccant inside is used a lot, so some people think sealed is
fine. I have no surveys to back this up, just personal observation with
a very limited sample.

On some GPSs, the weep hole is visible. It has a membrane valve. A
friend got this brilliant idea to seal up the weep hole. He took a trip
in an airplane with the GPS and the keys got sucked down due to the
pressure change. Sometimes when I go camping, I can't open the ammo
cases because the pressure change has sucked them down. So yeah, sealed
isn't all that good in some situations.

On Wed, 04 Jan 2012 12:13:56 -0800, miso wrote:

I didn't want to go into this because it gets complicated, but I buy dry
air from scuba shops.

Ok, you opened this can of worms. What you want is *DRY* nitrogen.
The stuff the dive shop sells is good enough. (I used to dive but
gave it up after all my stuff got ripped off). Basically, truly dry
nitrogen has to come from a cryogenic tank, which is expensive. The
measure if dryness is the dew point, or the water content in ppm. Look
for something like -70F N2 dew point or 10ppm.

A somewhat less critical source is the local drag racing tire
supplier. For some magic reason, they like to fill the tires with dry
nitrogen. The local Costco also does that.

Oh, if you're wondering why it has to be dry, think of the inside of
the pressurized box in terms of acid rain.

However, all this is overkill. What you want is any minimally
reactive gas that's dry. You could use CO2 if you could find a
suitable dryer. For pressurizing outdoor boxes, you only need 2-5 psi
differential pressure. Any more and you'll blow out the seals. I
learned that by pressurizing a radio to about 40 psi which caused the
plastic front panel, keyboard, and display to fragment and spray
shards all over the lab. Therefore, all you need is a bicycle pump
and a dryer from an air compressor. You won't get -70F dew point, but
it will be good enough.

Incidentally, the sloppy way to test if you're doing it right is to
put the radio in the freezer for at least 24 hrs. If you then open
the case, and find frost and snow on everything inside, you have a
problem.

You need your own tank. Air is cheap. Inspections
are not.

No kidding. I have several steel tanks that are ummm.... 10 years out
of date and need a hydro test. One spewed some rust when I bled it
down. The local gas house wants to give a fabulous $10/ea for them.

Tank, hose, regulator and the nozzle set me back $50. When I
blow the dust of out something, I don't hit it with refrigerant, which
is what canned air does.

I have several air compressors. Well, not counting two that are out
on semi-permanent loan, I have 4 air compressors. They're easy to
rebuild. However, for when I was blowing out my dive stuff, I used a
Gast oil less air brush compressor. It doesn't generate much volume
or pressure, but it also doesn't spray oil into the mouth piece.

NEMA with desiccant inside is used a lot, so some people think sealed is
fine. I have no surveys to back this up, just personal observation with
a very limited sample.

Yep. Desiccant will dry the air for a while. However, if you're
pumping water into the case by alternately heating and cooling the
case, it won't last very long. Desiccant works best on pressurized
systems.

Incidentally, I still pressurize Heliax coax runs (when possible and
except for the local ham repeaters). I recently discovered that one
of my original installs was still pressurized after 20 years of
neglect. When disassembled, there was no green slime and everything
was shiny and new looking.

On some GPSs, the weep hole is visible. It has a membrane valve. A
friend got this brilliant idea to seal up the weep hole. He took a trip
in an airplane with the GPS and the keys got sucked down due to the
pressure change.

Chuckle.

Sometimes when I go camping, I can't open the ammo
cases because the pressure change has sucked them down. So yeah, sealed
isn't all that good in some situations.

Install a one way check valve? I use a bicycle valve or plumbing air
bleed valve fitting for filling. It could also be used to equalize
the pressure before opening.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com
# http://www.LearnByDestroying.com AE6KS

I can see the desiccant being an issue if you don't service the box and
change it out. I wonder if they are depending on the heat from the box
to keep things dry inside.

I have a downconverters handy. [Learn by destruction stuff from ebay.
;-)] They just use a sealed case. Both have a black fuzzy thing inside,
purpose unknown. I don't think it is a desiccant.

Pelican and similar cases have check valves. I just curse and yank
really hard and the ammo cases open. It is is impressive on some of the
cans with good seals.

I can't believe what they get for ammo cases these days. You would think
with a decade of war we would be awash with cases. I was driving around
Palmdale, spotted an Army surplus store, and decided to check it out.
Small ammo boxes I got for $5 at the flea market were $30. I've bought
real transit cases for that kind of money.

On Wed, 04 Jan 2012 23:48:09 -0800, miso wrote:

I can see the desiccant being an issue if you don't service the box and
change it out. I wonder if they are depending on the heat from the box
to keep things dry inside.

I don't think so. The box won't get hot enough to do anything useful.
I think you have to get the desiccant rather hot before it will
release the trapped water.

I have a downconverters handy. [Learn by destruction stuff from ebay.
;-)] They just use a sealed case. Both have a black fuzzy thing inside,
purpose unknown. I don't think it is a desiccant.

The black fuzzy stuff is a carbon microwave absorbing sheet, intended
to absorb RF. The idea is to absorb rather than reflect as in a metal
shield.

Pelican and similar cases have check valves. I just curse and yank
really hard and the ammo cases open. It is is impressive on some of the
cans with good seals.

I can't believe what they get for ammo cases these days. You would think
with a decade of war we would be awash with cases. I was driving around
Palmdale, spotted an Army surplus store, and decided to check it out.
Small ammo boxes I got for $5 at the flea market were $30. I've bought
real transit cases for that kind of money.

Locally, we have:
http://www.surplusinc.com
They don't even list ammo boxes on their web page. They have a few
and yes, they're seriously overpriced. When Ft Ord closed, their
supply of goodies dried up. I'm not sure why, but I'm seeing zero
military surplus coming back from Iraq and Afghanistan.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 1/5/2012 9:16 AM, Jeff Liebermann wrote:
On Wed, 04 Jan 2012 23:48:09 -0800, wrote:

I can see the desiccant being an issue if you don't service the box and
change it out. I wonder if they are depending on the heat from the box
to keep things dry inside.

I don't think so. The box won't get hot enough to do anything useful.
I think you have to get the desiccant rather hot before it will
release the trapped water.

I have a downconverters handy. [Learn by destruction stuff from ebay.
;-)] They just use a sealed case. Both have a black fuzzy thing inside,
purpose unknown. I don't think it is a desiccant.

The black fuzzy stuff is a carbon microwave absorbing sheet, intended
to absorb RF. The idea is to absorb rather than reflect as in a metal
shield.

Pelican and similar cases have check valves. I just curse and yank
really hard and the ammo cases open. It is is impressive on some of the
cans with good seals.

I can't believe what they get for ammo cases these days. You would think
with a decade of war we would be awash with cases. I was driving around
Palmdale, spotted an Army surplus store, and decided to check it out.
Small ammo boxes I got for $5 at the flea market were $30. I've bought
real transit cases for that kind of money.

Locally, we have:
http://www.surplusinc.com
They don't even list ammo boxes on their web page. They have a few
and yes, they're seriously overpriced. When Ft Ord closed, their
supply of goodies dried up. I'm not sure why, but I'm seeing zero
military surplus coming back from Iraq and Afghanistan.


This black fuzzy thing is a small block of sorts. About the dimensions
of a bluetooth dongle. If I get motivated I'll open one up again and
send a photo.