How to get "in" to a repeater, and how close do I have to be?

[TimChgo9]

Okay.

 

Newbie GMRS person here.  While I understand radio communication (9-1-1 Operator, FIrefighter, Dispatcher, etc) I am not sure on this whole repeater thing.

 

I purchased some radios, and obtained a  GMRS license, so I could get repeater access.  I understand what a repeater is, and I also understand that some owners require permission, and such. My question is, once I get access, how close do I need to be to the repeater to utilize it, and if necessary, how could I build a repeater of my own, to facilitate access  , if I am too far away from the repeater I wish to access...

 

 

[zap]

First, it depends on the radios you are using. Most consumer grade FRS/GMRS radios can not be used with repeaters (they won't do the splits). If you can hear it, you can try to hit it. If you can see it, you can definitely hit it. It really just depends on the repeater's location and your location relevant to it.

 

 Repeaters are fairly simple things. A receiver, a transmitter and some circuitry to mix it all together. They can be a single, full duplex radio, or they can be based off of two half duplex mobile radios, and in some instances you'll see them based off of hand held radios (generally avoided in the commercial world though).

 

The things you need to know are the split (GMRS is going to be +5 MHz), and the PL tone (referred to as CTCSS commonly). When you are on a duplex channel on the end user, it transmits +5 MHz from the radios receive frequency sending a sub-audable tone (PL). If the repeater's receiver hears this tone, it unsquelches and keys the transmitter, re-transmitting the audio it hears on the output, which is 5 MHz below the receivers tuned frequency (because your radio is transmitting, the receiver is turned off, but everyone else will hear who is on the output). 

[TimChgo9]

The radios I have are not the "bubble pack" types, I picked up 5 Bao Feng UV82 and currently they are programmed without PL codes so I could avoid using repeaters until I got the FCC license.

 

I can here a fair amount of local traffic on a couple of the frequencies (A school, hospital security, and what sounds like a maintenance company.) I am not sure of the location of the repeaters, but there are two in the area that broadcast their ID and time at the top of the hour, and the signal is fairly strong. 

[zap]

You'll have to make sure you have the offset programmed in. Then just change the pl tones once you have permission to use a repeater in the area.