Radio Information for Airsofters

Looking for the best airsoft radio? Sorry, I don't know what it is. Manufacturers change model numbers and designs all the time to reflect changes in battery pack, charger, faceplate buttons, and housing colors. None of the radios I own are even made anymore. If you read on, I can tell you enough to help you make your own decision.

Bands

Airsoft players can plausibly use three radio bands.

FRS is the granddaddy of them all. FRS radios are compact, affordable, and may be freely used for any recreational purpose. No license is required. On the downside, FRS radios are limited to very low power levels and small antennae, which gives them a fairly low effective range. The FRS band includes fourteen UHF frequencies, and FRS radios may have an effective radiated power of up to ½ watt.

MURS is very new and poorly supported in the marketplace. Useful radios are available, but headsets suitable for airsoft use are rather less so. (This is not to say that there are none. There may be good gear out there. The problem is that none of it is explicitly listed or sold as gear to be used with MURS radios, so it's a crapshoot.) This is a shame, because MURS has a lot going for it. In particular, MURS offers five VHF frequencies, which are less attenuated by woodland terrain than UHF frequencies, and MURS also allows an effective radiated power of up to 2 watts. This might make MURS a good choice for event organizers who just need walkie-talkie service and don't care about headsets. MURS does not require any sort of license.

GMRS radios are the best and also the most complicated radios for airsoft use. GMRS may only be used by licensed users. Anyone can get a license, and no test or training is required, but there is a fee of $90 for a five-year license. The FCC is currently making no effort whatsoever to enforce GMRS license rules, and so many people are using these radios without a license. I do not condone this. On the plus side, GMRS handheld radios offer fifteen UHF channels, partial FRS compatibility, up to 5 watts effective radiated power, and a wide range of accessories. They can also be used with repeaters, which means anyone who actually owned a large field and cared to make a significant capital investment could easily set up a radio network that would ensure solid transmission and reception across the entire field.

Other bands do exist, including business class frequencies designed to be used with programmable commercial radios. These bands are regulated by the FCC, and unlike the GMRS rules, the rules for their use are strictly enforced. Licenses for these bands allow use of specific frequencies in specific locations. That may make them suitable for use by field owners, but makes them a bad choice for the average airsofter. As a rule of thumb, steer clear of any programmable radio, even if someone claims it's been programmed for FRS or GMRS use. It's very easy to end up in technical violation of the rules, and nobody wants to end up paying a fat fine to the FCC because of an airsoft game.

Power and Range

Advertising encourages us to focus on power as a measure of a radio's range, but advertising is misleading. In practice, the terrain is most important - thick vegetation and hills will clobber your transmissions and limit you to ranges far shorter than might be acheived on a featureless plane.

After terrain, efficiency plays a big role. Different brands and models may be extremely well-designed or they may be crap. The design and size of the antenna also plays a major role, and the typical dinky little antenna is a major reason why most FRS radios have limited range.

Assuming equal terrain and quality of design and manufacture, then yes, power does have a role to play. Generally, range will vary by the square root of power. That means that to double the range of a radio, I need four times the power, and to triple the range of a radio, I need nine times the power. One manufacturer loves to brag about having the only 5w GMRS walkie-talkie, but they don't want to admit that consuming 25% more power has only bought them 11% more range. Now you know.

Remember that higher power means higher battery drain when you transmit! If you run around with a 4w+ radio and talk much, expect to go through batteries pretty quickly. The Icom IC-F21GM is an outstanding GMRS radio, but it comes with a 7.2v 600mah battery that's lucky to last you three hours on the 4w transmission power setting.

All of these factors have to be considered if you feel like you need more radio range. Imagine that you have radio contact with a buddy 200 feet away. He moves ten feet farther away and you lose contact. If we ignore terrain features, you'd need to increase range by only 5%, which should require an 11% power increase. However, if those ten feet represent your buddy cresting a hill and moving down the other side, then what you really need is enough extra power to punch through ten feet of solid earth... and you can't be sure any radio will get the job done. If your buddy has a dinky little FRS radio, maybe the solution is to for him to go to a better-made radio with a larger and better-designed antenna.

Privacy Codes, aka "Subchannels"

Short version: Forget you ever heard of them.

A privacy code is an inaudible tone that the transmitting radio adds to the outgoing signal. Other radios can be set to filter out incoming transmissions and only let you hear the ones with the privacy code you chose. The restriction only exists on the listening side. Someone with privacy code zero set can hear any transmission on a given frequency.

In airsoft, this can be a nightmare. Imagine a situation where squad A is using channel 1, privacy code 1, while squad B is using channel 1, privacy code 2. Each squad is transmitting on the exact same frequency, but neither can hear the other.

If they're out of radio range with one another, this works fine... although so would using no privacy codes. If they're within radio range, their transmissions will interfere with one another, but neither will know it. All they'll know for sure is that they can't get through on the radio. Switching a radio to code zero will tell them that some other squad is transmitting on their frequency and that's why they can't get through, but they can't actually talk to the other squad and give them a gentle reminder about radio discipline without knowing what privacy code the other squad is using. This way lies madness.

Radio Sins

Most consumer radios are chock-full of settings that might make good sense if you were asking your wife where she'd left the stroller at Cedar Point but create a hideous nuisance in airsoft.

Some units have call tones, which let you transmit an irritating ringing noise to let people know you want to talk. Your airsoft teammates were already listening, and if they aren't responding, it's because they're busy shooting or they've been shot. Do not use the call tone.

Other units have confirmation bleeps or other noises that are sent to indicate that they've finished a transmission or have just received one. You must disable them or everyone else on your frequency will fervently desire your doom. Sadly, new radios often come with this feature enabled. Read the manual carefully and you will learn how to disable it. If you can't figure it out, return the radio. A radio that makes too much noise is unsuitable for airsoft.

Last but certainly not least, you must never, ever, enable VOX, also known as voice activation. VOX means that you don't have to hit the transmit key, because your radio will automatically transmit whenever you talk. VOX in airsoft means that your squadmates get treated to the melodic sound of you panting as you run, yelling when you're hit, yelling at someone else you think you hit, and muttering about how much your squad sucks for failing to back you up in that last shootout. It will not make you popular. Stay in push-to-talk mode at all times.

Radio Discipline

(Or, "Keep this frequency clear!")

Only one person can transmit on each frequency at one time. If two people try to transmit at once, they will effectively jam one another. Since some channels are very close in frequency to other channels, there may even be a jamming effect from other people transmitting on other frequencies! Everyone must therefore take care to only transmit when they have something meaningful to say, not to complain about their AEG or the taste of breakfast. If the urge for small talk is overtaking you, do something silly so that you get eliminated and have a nice chat face-to-face while you respawn.

To help work around radio's limitations, people long ago worked out some formal rules for making clear transmissions. Open your transmission by saying the name of the person you're talking to, then your name, then your message. When you're done, say "over" to indicate that it's someone else's turn to talk. If you're not sure you understood someone, or want them to be sure you did, repeat the transmission back. When you're completely done and the conversation is complete, say "over and out," instead of just over.

Here's an example conversation between Alpha (some random player) and Zulu (his squad leader):

"Zulu, this is Alpha, I have four hostiles in sight, moving northwest, towards our respawn, crossing in front of our position. Request orders. Over."

"Alpha, Zulu. Other friendlies are moving to intercept. Hold your fire until the reinforcements arrive if possible. If they engage you before then, hold your ground, make a lot of noise, and wait for support. Over."

"Zulu, Alpha. Copy that we should hold fire if we can, engage if we must, hold this ground and wait for support. Over."

"Alpha, Zulu, confirm your copy. Over and out."

Frequency Allocations

FRS has fourteen channels and GMRS has fifteen. Just to make things confusing, seven of those channels are shared. FRS channels 1-7 can also be used for GMRS. FRS channels 8-14 are FRS-only, and GMRS channels 8-15 are GMRS-only.

As a result, we should really think about three sets of channels: FRS, GMRS, and shared. Assuming two teams in an airsoft event, each one should get half of each group, with at least 1 channel reserved for the organizers as well. Here's my sample vision. I've used the channel numbering commonly found on GMRS/FRS 22-channel radios. Your particular radio may not have all these channels, or it may number them differently.

Example Radio Channel Assignments
ChannelDesignated UserFrequency Type
1OrganizersShared GMRS/FRS
2Team A Command Net
3Team A Squad One
4Team A Squad Two
5Team B Command Net
6Team B Squad One
7Team B Squad Two
8Team A Squad ThreeFRS
9Team A Squad Four
10Team A Squad Five
11Team B Squad Three
12Team B Squad Four
13Team B Squad Five
14Organizers
15Team A Squad SixGMRS
16Team A Squad Seven
17Team A Squad Eight
18Team A Squad Nine
19Team B Squad Six
20Team B Squad Seven
21Team B Squad Eight
22Team B Squad Nine

Each team's commander and squad leaders must be on a GMRS channel, which should probably be one of the shared channels in case one or more squad leaders only has an FRS radio. From there, the team commander will want to see which squads can use which band, and allocate frequencies accordingly.

Since one radio can only monitor one frequency at a time, the ideal model is for each squad to have an RTO who carries two radios. One of his radios monitors the command frequency, and one the squad frequency. The RTO stays close to the squad leader and relays (by voice or squad frequency radio) the team commander's orders to the squad leader. In a pinch a squad leader can be his own RTO, but it can be very difficult to pay full attention to two radio channels while simultaneously coordinating the squad's activities. A good RTO acts as a filter and only requires the squad leader's attention when the traffic on the command net directly affects the squad.

Last updated $Date: 2014/07/31 20:10:43 $.

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