Our town has an annual 3 day "festival", about 40 craft and food booths set up, and I've been asked to see what it would take to have speakers disbursed around the grounds for event announcements etc.... I'm the resident (volunteer) electrician - and need to come up with a low budget solution. I already have 6 or 8 20' poles used for for power distribution and lighting - donated aerial wire distributed via POCO donated poles and holes was the most cost effective way to distribute power and lighting circuits. Have 2 200A 240v service entrances, and multiple subpanels. Runs are several hundred feet long.
Is there any feasible way to use the ac wiring to implement a PA system (voice grade - no music) connected to each pole? In my youth I worked with some "carrier current" signaling systems - details long since forgotten. Conceptually couple the PA amplifier to the line in the "office", and "decouple and detect" the audio at each pole/speaker location. I guess amplified speakers would work. We might get rain, but speakers would be stored inside 360 days per year.
Appreciate any and all pointers or ideas.
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The best way would be to run SEPERATE wire for power and speakers. Amplified speakers for this application would not be the best thing to do. The type of speakers that I would use, would be 70 volt commercial paging horns rated for outdoor use, and a 70 volt mixer/amplifer such as a Bogen or University sound brand. The city I live in has a festival during the 4th of July, and do the same thing. The wire isn't flown though, it is just ran along the ground and up a pole to speakers. The problem with leaving low voltage wire up year around, is that wire rated for that, is very expensive. a simple 16awg or 14awg 1 pair wire would suffice.