So, you've made it past the challenge of navigating the FCC website and you got your new GMRS call sign. You may have heard or read that you now have the privilage of using a GMRS repeater to extend your range greatly, and to expand your ring of radio friends. Maybe you have even heard the others on the repeater through your radio, but you have been unable to reach back out to them and make contact. The following is a simple instructional, intended to help new operators get their GMRS radios repeater ready without the confusion and delay that many of us experienced in the beginning. It's really a very simple thing that can seem complex until you understand the basic info you need to make this happen. Let's get it explained really quick, but there is a simple formula included for your convenience. (Just scroll down a bit.)
The first thing you will need to know about the repeater you want to program into your radio is the frequencies it operates on. All GMRS repeaters operate on one of the 8 frequency sets the FCC has alloted for GMRS repeater use. Each of these frequency sets uses 462.XXX MHz for the repeater output and 467.XXX MHz for the repeater input. The "XXX" represents the last 3 digits in the frequency, which will vary by repeater and will be from the following list of numbers:
.550, .575, .600, .625, .650, .675, .700 & .725
The repeater you are targeting will require that you program your radio to transmit on 467.XXX and receive on 462.XXX in all cases. The difference between these two frequencies is 5 MHz, and often this difference will be referred to as the "repeater offset". If your radio demands an input of this kind in order to determine the TX frequency, the input should be "+5 MHz offset". In these cases, you will input the RX frequency (462.XXX) and the offset (+5 MHz) and the radio will calculate the TX frequency accordingly.
Many Type95 Certified GMRS radios come pre-programmed with all 8 repeater frequency sets, including the +5 MHz offset. In this case, the operator will only need to set the radio to the correct repeater channel and then enter the correct repeater tones. If done correctly, your radio should now transmit and receive on the targeted repeater. This is the simplest and most common way to set your GMRS radio to work on a repeater.
The other thing you need to know is the repeater PL Tones (also called CTCSS or DPL). The purpose of these tones is 2 fold; requiring certain tones in order to transmit into a repeater makes it less likely that unwanted or unlicensed traffic will make its way into the repeater, and the RX tones keep the radio operator from hearing unwanted traffic which is not coming through the repeater (like simplex signals). The tones are chosen by the repeater owner and are made available to licensed operators through various resources online. There are 2 types of tones generally used by GMRS repeaters, which are CTCSS & DPL. Most Part95 Certified GMRS radios will have a full list of these tones available in the radio programing settings.
Only the TX tone is required for access to a repeater, leaving the RX tones optional. If one does not enter RX tones on a repeater channel, all radio traffic on said frequency and in range of your station will be heard, whether coming through the repeater or not. In these cases, it is very likely to hear local FRS stations sharing the frequency. This can cause confusion as to which traffic is on the repeater, and which is not. For this reason and others, it is advisable to use the optional RX tones on all GMRS repeater channels. And use simplex channels to hear or respond to simplex traffic. This practice will be sure to make your radio experience more enjoyable.
No matter which way you program your radio, don't forget to SAVE the channel once you have this information input properly. This way, you won't have to go through this all over again after resetting the radio. Just go to the repeater channel you programmed in and saved and LISTEN for a bit, then START TALKING! Most repeaters will give you some kind of report to confirm that you successfully transmitted through it. You should hear some 'dead air' or 'hang time' followed by a 'courtesy tone' or something like that. So, key up that microphone and wait 2 seconds before saying your call sign in full. Unkey, and you can leave it at that and wait for a response. Or, you can add something to your call sign, like "This is W?#@123 looking for a contact" or whatever suits your fancy.
So, after all of the mumbo jumbo in the explinations about the WHY and When and HOW, the information needed to access a GMRS repeater is very simple:
RX & TX Frequencies + Corresponding Tones = Repeater Access
There is really nothing more to it in most cases. You may run into rare cases where a GMRS repeater requires 'split tones' (meaning that different tones are used for RX & TX in order to make access a bit more difficult for unwanted or unlicensed traffic. And, actually some radios do not allow for 'split tone' entry, but others do. Also, there may be some cases where a repeater owner decides not to use tones at all to make access easier. (However, this also makes interference through the repeater much more likely.) The general standard in GMRS is to follow the model explained above, although there really is no entity that takes responsibility for repeater frequency coordination and standardization apart from the repeater owners themselves.
Please make sure to read, understand and follow all FCC GMRS regulations and that you operate in a manner that is respectful, family friendly, and kind. GMRS repeaters often have large area coverage, meaning that whatever you say on the repeater could be heard by hundreds of listeners. These communities are mostly self-policed, meaning that someone out there that cares is usually going to make sure to put negative pressure on anyone who is blatently operating against the FCC regulations. CB radio regulations may not be enforced any more, but GMRS certainly is different in that respect. At the same time, enjoy the many advantages of being a licensed GMRS operator and part of the wonderful and knowledgeable community that shares the repeater with you willfully. I'm sure that you'll find that it's a lot more than radio and that it will be an extremely benfeficial addition to your life!
WRFR912 / KJ5JNJ, Justin