I expect lethal voltages on coax.
5000 watts 50 ohms = 500 volts @ 10 amps.
Even a 288 watt transmitter has 120 VAC of RF on it.
And 120 VAC of RF hurts much more than 60 cycles.
From: Mark Radabaugh via Af
Sent: Monday, November 10, 2014 12:10 PM
To: af@afmug.com
Subject: Re: [AFMUG] New site DC power help
Please mark the hell out of the cable if you decide to put 120VAC on it.
Technically it will work just fine. It's just pretty hazardous to the guy
who comes along later, has no idea what it is and grabs hold of the center
conductor, or tries to cut the line.
Nobody is really expecting lethal voltages on coax. They probably should be,
and RF can be deadly, but it's out of the ordinary on LMR type cables.
It's also really ugly if one of your own guys gets confused and connects the
LMR with 120VAC on it to your shiny new Remec radio head.
Mark
On 11/10/14, 12:27 PM, Chuck McCown via Af wrote:
Neutral bar is in the circuit breaker panel. It is where all the white wires
terminate.
You attach, clamp, solder a white wire to the shield. Extend the insulated
center conductor and put it on a circuit breaker.
Instant $120 VAC appears at the top of the tower. Depending on the size of
the coax, you could easily do 30 amps or more.
From: Josh Luthman via Af
Sent: Monday, November 10, 2014 9:37 AM
To: af@afmug.com
Subject: Re: [AFMUG] New site DC power help
Well I was thinking...
AC -> battery charger -> 24v batteries -> coax up the building
coax -> 24v regulator -> PacketFlux
What is the neutral bar?
Josh Luthman
Office: 937-552-2340
Direct: 937-552-2343
1100 Wayne St
Suite 1337
Troy, OH 45373
On Mon, Nov 10, 2014 at 11:29 AM, Chuck McCown via Af <af@afmug.com> wrote:
Why DC? Why not just tie the center conductor to a circuit breaker and
make sure the shield is tied to the neutral bar. Then you have all kinds of
options up there.
From: Josh Luthman via Af
Sent: Monday, November 10, 2014 9:20 AM
To: af@afmug.com
Subject: [AFMUG] New site DC power help
I am getting onto a new site that is a building. The owner has given me
free permission to use anything I want that Sprint left. That's the nice
building as well as 6 heavy duty >1" thick coax runs from the base to the top
of the tower.
What I would like to do is run DC on one of these. They have connectors
that look twice as big as N connectors. How can I go from this connector to a
DC power supply? What about at the top from the coax to a regulator?
Am I correct in assuming the center pin would be hot and the
outside/threading be neutral?
Would 24vdc be OK for this? Or would 48vdc be better?
Thanks in advance for any help! I'd like to avoid running 10 feet of wire
and soldering if at all possible.
Josh Luthman
Office: 937-552-2340
Direct: 937-552-2343
1100 Wayne St
Suite 1337
Troy, OH 45373
--
Mark Radabaugh
Amplex
m...@amplex.net 419.837.5015 x 1021
