Simplex

Simplex – Local Communications / Special Situations

Simplex means “radio to radio”.

Whenever possible under normal circumstances, or if we should be faced with one or more repeaters being down or inaccessible, this is an option we all should have and know how to use.

This is something we hope to see us all explore so that we know with whom and from where it is possible to communicate via simplex. Understanding how and when to use simplex rather than a repeater will require some practice. We’re hoping for there to be a presentation, some practice, and some programming around this at a near future meetup.

For hyper-local communication GMRS channels 4-7 may be appropriate (1-3 may collide with repeater frequencies in the Coastal Hills and Cazadero), and in some cases intra-area communications are possible. A good use case for this would be a group of people dealing with a local issue where they are all within range of each other.

CHNGRN

If the repeaters are down we have the option of using simplex on our repeater frequency. I have started adding a channel called CHNGRN to radios I program that is for this purpose. It should not be used unless the repeaters are down, and if it does need to be used it will have a range limited by your location and equipment just as any simplex communication would.

CHNGRN is a special SIMPLEX frequency that is intended to emulate a feature we sometimes call “talk around”. It transmits on the same frequency and with the same CTCSS tone as the repeaters do. Only people within radio to radio range will hear you. This is useful in a situation where the repeaters are not working, allowing you to talk to local people who have radios monitoring the repeaters.
The added channel for your radio would be as follows:
Frequency: 462.575
Tag: CHNGRN
Tone Mode: TSQL
ToneSql: 192.8
Mode: FM
Power: High

GMRS Simplex Frequencies

GMRS 1-7 are simplex channels. You can use one of these to talk around your local area.
GMRS 8-14 are VERY LOW POWER simplex channels. Just avoid these unless there is some special need.
GMRS 15 is a HIGH POWER simplex channel. This is really for those using mobile radios, but you can use it to talk to someone more locally as well.
GMRS 16-22 are in use by repeaters. Especially DO NOT USE GMRS 16 unless it is an emergency and the repeaters are not working.