In my experience, radio communication can be a real pain. The pain comes from three principle sources: (1) the radios themselves (2) the wiring harness (3) noise at the track. I don’t claim to be an expert in solving radio problems, but I can hopefully provide some useful information.
The first question to ask yourself is if you really need radio communication. I’ve run plenty of events without radios, so my answer would be no. If you know you don’t have radios, you make plans to communicate from track to driver (usually with signs) and driver to track (with some kind of hand signal). The pit has to be a lot more attentive without radios. As soon as you put a radio in the car, everyone is a bit more relaxed. But that’s not always a good thing. If the radio goes out, it can mean you’re even less prepared than you would have been if you never plugged them in. So even if you run radios, you have to have a backup plan. That said, you probably won’t and when that comes back to bite you, there’s a preemptive “I told you so” that will fall from the recesses of your memory.
So once you decide to get radios, which one should you get? There’s more than one competing technology. Some teams are using phone apps to do voice messaging, but that requires the track to have decent cell coverage, which isn’t always a given. Radios will still work though. Among radios, a critical choice is which radio frequency you want to use. Each has its advantages and disadvantages. CB radios have respectable range on a flat highway despite their low power, but the lack of channels and really long antennas makes them impractical on a race track.
Enter the grown-up walkie-talkie. These operate on the FRS, GMRS, or MURS bands (and possibly more depending on the radio). Let’s review the various bands you’re legally allowed to use (in the USA).
FRS: The Family Radio Service band is composed of 22 channels in the 462 and 467 MHz range. This is designed for backpackers and similar activities. Depending on the channel, you’re allowed to transmit at 0.5 to 1.0 watts without a license. While it seems like 22 channels isn’t a lot, you can also include a privacy tone that squelches anything else that doesn’t include the privacy tone. It’s not true privacy. It’s not encrypting your message. It’s more like a filter that removes everyone else and lets you listen to just who you want to listen to. There are dozens of privacy tones, so it’s highly unlikely you will overlap with users outside your group.
GMRS: The General Mobile Radio Service band is composed of 15 bands in the 462 MHz spectrum. The channels completely overlap FRS channels 1-7 and 15-22. GMRS radios are allowed to transmit at 5W, but you need a license for that. The current cost is $90 for 5 years, but there are recommendations for removing the licensing fee altogether.
MURS: The Multi-Use Radio Service band has a longer wavelength (151 MHz) than the FRS/GMRS. MURS limits you to 2W for transmission. There are only 5 MURS channels, but the dozens of privacy codes means it’s unlikely you will collide with another user. There is no license required for MURS operation.
One of the most popular grown-up walkie-talkies is the Baofeng UV-5R. These are about $25 and can operate on the FRS, GMRS, and MURS frequencies. They can also operate (legally or illegally) on many other frequencies. Want to become a HAM radio operator? You can do that with a UV-5R.
Out of the box, the UV-5R is not set up for frequencies you want to use. You can manually tune them, but it’s much more convenient for users to page through the channels with frequencies and privacy codes already set. To do that, you have to program the radio. That sounds like a daunting task, but it’s really just filling out a spreadsheet. There are lots of programming resources out there already. Here’s a good one. You’ll need a serial cable for the radio-to-computer connection and the CHIRP software (Mac, Windows, Linux friendly). Make sure that the serial cable comes from Baofeng and not some cheap knock-off.
I set up my radios with 5 MURS and 5 GMRS bands, each with its own privacy code. The MURS bands are set to 2W and the GMRS are 5W because that’s what the law says. But like everything else in racing, someones always breaking the rules.
I’ve had more problems with wiring than radios. Rather than buying the wrong stuff, I recommend having Troy Hogan at Nerdie Racing set you up. It’s better to pay for expert customer service than to buy the wrong thing several times.
Noise on pit lane can be pretty loud, and can easily interfere with voice communication. You’ll probably want a headset with around-the-ear insulation. I don’t have a product recommendation here, and if you do, please leave a comment.