Each repeater handles two 6.25 KHz "channels" simultaneously, if that's what you mean...? But both "channels" are continuously received by the portables/mobiles. The transmission is one big interlaced TDMA signal that takes up the full 12.5 KHz spectrum even if only one "channel" is in use.
I can be on user ID 00000100, TG 00000100 talking to you, user ID 00000200 on one channel... And someone else can be simultaneously talking as user ID 00000300, on TG 00000200 to user 00000400. And we won't hear each other. On the same repeater. If you buy their trunking stuff, you can then link repeaters at a site, and each repeater box means two more simultaneous "channels" of data. How the system directs the mobile/portables as to which frequency to monitor, I don't know. Moto uses "color names" for the channels. The local system some hams here built has two "colors"... one is local traffic, the other is routed to the IP link to some other repeaters full-time. In practice, these are programmed as "Channel 1" and "Channel 2" in the portables/mobiles. Want to talk locally? Channel 1. To someone on one of the IP linked repeaters, "Channel 2". AFAIK the repeater doesn't "care" at all about any of this. The rigs are receiving both channels at the same time, and just watch for the "Color Code", Unit ID (in the case of unit-to-unit calling) or their TG and open "squelch" appropriately. That probably changes in the trunked environment - the repeaters obviously must be "active" in deciding which transmitter to turn on. Don't know how that piece works when you grow beyond a single repeater. I assume there's data being transmitted from one or more transmitters continuously that tells the mobile/portables when to frequency hop. In IP linking without trunking, I believe all transmitters go active if you transmit on the "color" that's linked. Don't know how it handles "glare" (Someone transmits on Repeater A's "color code" that's IP linked to Repeater B and someone else keys up at the same time on Repeater B with the same "color code".) Also don't know what gets priority if someone places a unit-to-unit call on the "local color" at the same time as a "remote" linked call for the same Unit ID comes in, but that logic would be in the portable/mobile rigs, not the repeater. Nate WY0X On Mar 11, 2010, at 9:10 AM, MCH wrote: > And how many of these TGs can be used in a repeater at the same time? > > Thanks, > Joe M.
