Thunderknight is correct. I was responsible for our Motorola 800 MHz. FM analog Spectra-Tac repeater systems. All receivers were connected to the hub (or voter) via telephone lines (costly), and when they weren't receiving, they would send a continuous tone down the phone line. Because the method of "signal quality" and not signal strength got the best sounding signal through the voter/comparator, went to the console, and back out on the repeater output. I forget the tone, but it was deafening and necessary for the voter to work correctly. We had two completely separate repeater frequencies, five receive sites, and four transmitter sites. The transmitter sites each had a backup. That's why there were four sites and only two working separate independent repeaters. Most of the time, when the system(s) would fail, it was 85% telephone line faults. I remember meeting the radio repair contractor and Illinois Bell Telephone and getting them access to water towers, tops of tall buildings, and tower sites.
Again, the costs of telephone lines were costly! We could have utilized microwave links, but the powers-to-be opted not to purchase the microwave relay system and paid for telephone line interconnects through the nose.
Yes, there was no reason to listen to the receive sites because the signal they sent was over telephone lines, so you could only listen to the voted signal on the output of the repeaters. Or, for some reason, if you wanted to hear weak hand-helds, you could listen to the inputs, but to me, that was a total waste of time.
The agency I worked for (I've been retired from there 15 years) disbanded that Spectra-Tac system for police and kept ONE transmit site with companion receiver at the same site for Public Works. Everything else was dismantled and scrapped, I imagine. The agency has been with a central dispatch agency (DU-COMM) on Starcom21 for about ten years.