Need suggestions for system / site proposal.

[EC-7]

I am in charge of a local security company's radio comms and also a neighborhood watch group that is in need of installing 2 antennas and a repeater at a new location. The security company works on VHF and has a freq already, and the neighborhood watch uses CB radios.

The location is a church / school, and one of our neighborhood watch members is the principal there. The security company also watches the church and so does the neighborhood watch group. They use it for a base station on Halloween and other holidays / events with a temp antenna.

I asked the principal about putting up 2 antennas (1 CB and 1 VHF) and a repater equipment at the church, and he said he was OK with the idea, but I would have to submit a proposal to the board members for final approval.

I think its pretty much a sure thing that we can do it, but I need to know what do do for the proposal. How do I write it up, and present it to them. Here is what Ive got for info.

CB setup plans:
1 18' verticle antenna, mounted on the roof, possibly in a inside corner where its hidden from normal sight.
50-100' of RG-8 coax, ran into a office we use, and I plan to terminate it in ajunction box. Id like to be able to have the CB locked up, and when in use, plug it in, and use a 10' jumper between the radio and wall junction box.

VHF Repeater setup:
1 6' verticle antenna, hidden in a corner if possible.
50-100' of 9913 coax, ran into the office, in a locked 19" cabinet.
Radios are Motorola Maxtracs running under 25W.

We arent too picky on the location of the antennas, even hidden they should provide the coverage we need. Im 1st concerned about safety (lightning and electrical code, which I have a master electrician helping with install), second is hiding the antennas from normal view (shouldnt be too hard due to building shape), and third concern is coverage.

Any ideas or help would be wonderful. Thanks.

[n2mdk]

One suggestion if you don't have the coax already go with Times Microwave LMR-400 it's at least as good as 9913 and because it uses a closed cell foam dielectric and doesn't have the water migration problems of the Belden.

[jim202]

There has been at length discussions about using LMR type coax for repeater use. The
double shield is comprised of a braid and a foil shield. This dissimilar metal has caused
noise problems to repeater systems in the past. If at all possible, I would suggest looking
at a different cable for the VHF repeater. You might not see the noise problem show up
right away, but given enough time and moisture, a slight breeze will generate noise.

As for grounding the antennas, both the building insurance company and the National
Electrical Code has guides on this. The electrician should be able to walk you through
the 250 section on grounding. Don't forget to tell him that this falls under the
communications or telecom section. Don't skimp on the grounding.

Jim

Originally Posted by n2mdk

One suggestion if you don't have the coax already go with Times Microwave LMR-400 it's at least as good as 9913 and because it uses a closed cell foam dielectric and doesn't have the water migration problems of the Belden.