Repeater for Confined Space Team?

[vamedic826]

The question That I have and would like some feedback from some of the fine minds on this board. We have an industrial facility and have put together a confined space team. The Question that I have is we are an all UHF system with several frequencies and repeaters in use in the facility. There is no question that the team operations will be on its own restricted access channel. But should a fixed location repeater be used or a vehicle mounted repeater?

[Bill_G]

Need more info.

What kind of confined space? Hopper belt tunnel under grain silo? Concrete mixer barrel? Some confined spaces are normally occupied by product, and cannot have a radio system permanently installed, but are so well shielded from the outside a portable radio has great difficulty. OTOH, some confined spaces are hazardous service areas with excessive noise, or dust, or noxious gases, but could have a terminating antenna from a distribution system installed.

[vamedic826]

Bill,
I understand where you are comming from, it is mainly, a water floom (concreate treanch), Metal enclousers, Pipes, Furance Basement, etc.

[Bill_G]

Will this proposed repeater be used for the crew to talk among themselves, or back to a central command?

[vamedic826]

Just for the operations there is already other channels in place to talk back

[Tom in D.C.]

If you're talking about radio ops in the emergency area only then perhaps you don't need to bother with a repeater setup and simplex operation would work well for you.

[Bill_G]

Tom and I are thinking along the same lines. Is your team satisfied that a repeater is required to talk from within the confined space out to the incident command on site, or has simplex served you well? Do you have multiple confined spaces with different coverage issues?

For instance, under the rolling mill at a steel tube factory, simplex barely reaches 100ft. At the same factory, the service tunnel under the arc melt is totally radio dark. At a silicon fab, a simplex radio cannot talk from inside the building to outside the building from any location. Inside, portables have a very limited range depending where you are in the fab. All of the confined spaces are radio dark.

One final question: Do you intend to reuse existing portable radios, or would you consider all new everything? The reason I ask is because local sewer inspectors have had great success using Mototrbo in digital simplex mode for several blocks underground to the crews above.

[vamedic826]

Thanks for the Response. Not trying to give a short answer but there is several different locations. The Flume, Simplex would work but Alloy Basement Simplex does not work with out someone relaying from the steps. Also in the Alloy Basement with out the relay they can not hit the current repeater that is mounted on a Roof line. (This is why I was thinking of a Mobile repeater that could be set up near the area of operation.) They are only two places that I know of that are Radio Dark. Pretty much you could hit the current repeater. But we don't want to use the current repeater because everyone and there brother out hear has a radio and we kind of want a private channel with out people walking over our operation and want to make sure that we have the coverage that we need to do the Job Safely

[Bill_G]

Okay. Good enough. For the situations you are describing I am going to suggest a standard low power 10 watt UHF repeater on it's own channel with a splitter, two mag mounts with salt shaker antennas, a 100ft reel of RG8 for the interior of the confined space with the antenna on a convenient ceiling conduit, and shorter 20ft section of RG8 for the exterior with the antenna on a telescoping tripod. The whole thing can be stowed in a transportable locker and deployed quickly. I've put these together for ERT's numerous times.