Radio Guru's. I gotta question.

[Amianthus]

All you radio guys, I have a question. Please pardon my ignorance.



I am a Firefighter for our local town (I use that term loosely). I also have a walk unit that I use for my duties as such. I have the unit programmed with the sub audio codes to catch our county repeater. Using my County Sherriff frequency this works just fine. But county Fire won't work. Now, the Sherriff's frequency is transmitted on a different frequency than the receiving frequency. However, our fire frequency is the same receiving as transmitting. I am having extreme difficulties transmitting county-wide. Or even just transmitting in our district (because of terrain). My understanding of repeaters is that they receive on one frequency, boost the signal, and transmit on another. Just as how the County Sherriff's frequency works. But when I asked someone about why the County Fire doesn't work the same way, I was told that we have a simplex system.



My question is this, what is a simplex system and how does it work? Once you explain this to me, I may be able to figure out a way to fix our walk units (and some of our mobile units) so that they function when we need them to. Thanks in advance.

 

[ToolManTimTaylor]

Double Check with Mack Truck as he is now running a whole new system I think.

 

[The patriot]

I'm not sure, but I dont think the simplex can split frequencies, and thus will not be compatible with any repeaters. (This will drastically limit your range)

It will only Rx and Tx on the same frequency, though you might have the CTCSS with that channel.

It could also be something easy as programming in the proper "split" into your unit.

This is what I think anyway.

You need to talk to a ham radio dude.

Eric

 

[Casey Ray]

With a simplex repeater, there is no frequency split, but like The Patriot said you might possibly need a ctss tone. You can read more about simplex repeaters here:



Simplex Repeater





Bocifus