"windcrest" wrote in message
...
On Aug 27, 12:02 am, "Robert Green"
wrote:


stuff snipped

I have no idea how 18GA speaker wire is gonna work for an intercom

I do, it will be just fine.

no intercom made in the last 40 years works on 8 ohm speakers.

I've got a whole set of RatShack units that work quite nicely over speaker
wire and I don't believe they're a day over 20 years old. (-: I intend to
pop out the components and mount them in a louvered stainless box I have
lying around that I know is even older because it was recovered from a fire
in 1980! I also have a little mike with a built in amp from Ebay today for
$3.65 (shipping included!!!) that I might decide to use as the sending
microphone if the RatShack unit doesn't sound clear enough after I
transplant it.

Truthfully, sometimes it's to my advantage (and amusement) if Jehovah's
Witnesses can't hear me clearly even though I can hear them. The Shack
I-com actually runs on 22GA stranded wire, but it's delicate wire and I
wouldn't want to depend on it surviving a conduit leak.

Additionally there are better ways to do the video than modulating a
camera onto what, RG59U? For all that work you should just use RG6
quad shield.

RG6QS is way, way overkill for baseband CCTV work. RG59U has been working
just fine and I have rolls and rolls of it. I use QS for pumping the
incoming broadband CATV feed around the house but it would be a waste of
money using it for low-bandwidth black and white board cams.

I would seriosly just look at getting AC power out to there above the
priority of the LV wires. Is there a lamppost nearby to tap off?

Doing that means working to code, inspection hassles, potential shock issues
and things I'm not willing to get into when I am certain what I have planned
will work quite nicely. AC power to the post would only complicate things
and add serious expense, hassle and potential lethality to the project. The
lamp post is not meant to really function as a lamp - it's there to mostly
house all the aforementioned components in something with reasonable SAF. I
will probably mount a photocell activated LED or some other 12VDC type of
light inside the post to provide just enough illumination to light up a face
at night. There's a very powerful streetlight just across the road that
provides more than enough illumination.

If you do insist to make a run out there then I'd use the 1.5 inch
black coiled stuff with no joints in the run (what the sprinklers
use). No need to trench, just rent the machine that pulls it through
the ground at an 8 inch depth (Google how sprinklers are installed).

That sounds like an interesting idea if my underage labor force doesn't work
out. I've seen that sort of machine on TOH. Not sure it would work in this
mix of clay and rock, but I will certainly look into it. IIRC, that
machine's best feature is its ability to run under driveways and walkways
that don't lend themselves to open trenchwork. I am not facing that sort of
problem. I've got an unimpeded run of dirt to the proposed location of the
lamp post.

Pulling wire/coax through any plastic tubing is a hassle, its sticky
and binds up easily especially on a run that long. Especially that
speaker wire you speak of, that will bind up so tight you'll be lucky
to pull it the first 15 feet, believe me speaker wire will bind up
solid even on a straight pull, forget a curve. Additionally you wont
be able to grease the wire enough with pulling silicone, so you may
want to consider installing a valve box at the half-way point as a
pull box or even two valve boxes.

I'm probably going to cheat and pull the wire through while the conduit is
still above ground. I don't anticipate much trouble that way although I
agree once it's in ground, pulling any more cables or replacing any that go
bad will not be a cakewalk.

I still think you would be better off just running power with UF alone
then go entirely wireless with intercom, video, gate control, motion
sensors, headlight sensor, vehicle sensor, etc. The reliability/
security of wireless is greatly improved over the last 5 years.

In the DC area, there have been some serious wireless issues with garage
openers, car key fobs and other gear. There are several military
installations that have been working on jamming IED's - wireless IED's - and
every once in a while, RF gear mysteriously stops working around here. With
all the RF spectrum reallocation occuring recently, I'm not sure what
low-power "must accept all interference" devices will stay working
throughout the next five years. Apparently, when the local garage door
openers began to get "stepped on" the Air Force said "tough nougies" we own
the frequency, go pound sand.

When the signal absolutely, positively has to get there, wired is the only
way to go. At least IMHO. Wireless video is especially crappy around here
and none of the cheap 2.4GHz gear works well enough to consider unless you
build your own hi-efficiency yagi antennas. I've done that and can testify
that they ain't pretty and have seriously low SAF. The upside was that I
was able to catch the local crackhead who had been breaking into cars by
installing a wireless cam inside my van.

So I agree: wireless has its place, just not in this application. The
wireless CCTV gear that *does* work well enough for this app requires a
license to operate and costs real $$$. If renting a trencher could make or
break this project pricewise, effective wireless is way, way out of the
picture.

I am trying to limit the value of any items mounted on the lamp post in case
someone decides to run off with it or run into it with their car. Don't
laugh - the next door neighbor's house is at the end of the road at a
T-intersection and they already have had a car plow into their living room.
The worst part is that the cops that came weren't even surprised. They said
people run into houses all the time, especially around steep curves or at T
intersections where the road just runs out.

The little board cameras I am using cost less than 12 bucks (!!!) from
Supercircuits and are more than adequate for the task. They are so cheap
that I am planning to mount one in each pane of the lamp to give me a four
way view. They'll be feeding into a 16CH MUX that I got for $45 on Ebay
that used to sell for $600 just a few years ago!!!

I might look into using baluns to reduce the four RG59U cables that would
require to a single CAT 5 run becauseCCTV balun components have gotten
incredibly cheap in the last few years, but the truth is, doing that would
probably cost the same as running four discrete coax cables.

I might pull a CAT-5 run to the lamp post just as insurance and to allow me
to add other gear I haven't thought of yet like a sensor to determine if the
gate has been opened or a PIR to detect when people approach the lamp post.
With a little early warning I might finally be able to catch the FedEx man
before he can rush up to the door and leave a door tag saying "we missed
you." (-: What was I saying about "mission creep?"

Thanks for your input. I'll be googling sprinkler installation tools
shortly.

--
Bobby G.