RF Communications for group rides

[nkemp]

This post tries to summarize the options and define a good alternative for group ride RF Communications. Since this is a topic without a common knowledge base, I'll try to create a RF communication baseline (and thus created a long post). I'll also try to be US laws legal and accurate but I am subject to being wrong without notice.

When two or more cars are out for a group ride, it is handy to have 2-way RF (radio) communications between the cars. It makes things like navigation, gas stops, lunch breaks and car troubles a lot easier to communicate.

The best communication alternatives provide clear communications within a reasonable distance (a few miles for our needs). This is a function of the quality of the equipment, frequency used, output power and antenna. More power is not necessarily better since less power into a better antenna can produce a more usable signal compared to more power into a poor antenna. The stubby antennas found on handheld transceivers are not good antennas. An externally mounted properly tuned antenna will provide significant improvement.

External antenna is an important part of this discussion since radio use with antenna in the car looses range due to the car's metal exterior. As such, an external antenna is a good improvement and an important factor because it gets and receives signals better. If you run without an external antenna you will have more difficulty getting a good signal as range increases or conditions worsen.

More range also improves safety since it allows the cars to spread out more reducing the opportunity for a multi-car accident (caused by someone is filming the parade of DeLoreans)

There are a variety of usable RF operating bands:

Band License Detachable antenna
Ham Yes Yes
MURS No Yes
CB No Yes
FRS No No
GMRS Yes Yes

Amateur Radio (Ham)

In terms of usability, this is the best option. Range, equipment quality, and usability for our application is right on target. The trouble here is that every operator must be licensed and the licensing process is a test. The good news is that the test question pool is published and if you study the pool, you can simply learn the correct answers. No Morse is required. It's easy to get a ham license.

Since many users are not ham licensed, this is not really an option

MURS

MURS (Multi-Use Radio Service ) is an unlicensed two-way radio with a power limit of 2 watts and allows detachable antennas. In terms of our application for use between cars, this may be the best technical solution. Good equipment quality can be had, 2 watts is a good power level, the frequencies allocated operate nicely for our use, privacy codes are allowed and you can buy or make external antennas.

The downside of this band is that it is not as common as FRS/GMRS and the probability that manu already own FRS/GMRS equipment.

CB

CB (Citizen Band) is still alive and has always be questionable relative to if it is "well". If CB wasn't such a circus, this could be a usable alternative.

FRS

FRS (Family Radio Service) are those little walkie-talkie type radios available everywhere. Initially the units were FRS only but now FRS only units are getting harder to find new. FCC requirements limit them to .5 Watts and the unit and antenna cannot be detachable or modified. With regard to range indicated about the unit ... they are more suspect than the claims of the supplements found in your spam folder. One half to one mile are better expectations. You may get better in certain situations but don't count on it.

GMRS

GMRS (General Mobile Radio Service) units are the upscale versions of the FRS radios and require a license to operate legally. Handheld units can put out up to 5 watts and can have a detachable antenna. GMRS only units can be had but are not as popular as the dual FRS/GMRS units. Within this product offering, quality costs. Quality covers ruggedness, water resistance and signal quality.

FRS & GMRS Channels

- Channels 1 through 7 are dual FRS & GMRS. I believe these are limited to .5 watts regardless of the radio
- Channels 8 through 14 are FRS only and are limited to .5 watts
- Channels 15 through 22 are GMRS only and can have higher output levels depending on the unit

FRS/GMRS Combo Radios

Most bubble pack units found at stores are dual FRS/GMRS units. They range in price from incredible cheap and up. The cheap ones may not give you the communication quality you expect, especially as they get farther apart and with more obstructions. Again, the advertised range is a joke. You might get that range from one crater edge to another crater edge on the far side of the moon where there is no radio interference. For our use, assume that it is a couple miles and maybe more if conditions and terrain are right. It may be less as well. FRS/GMRS frequencies operate in a range where they require line of sight between units. Hills, bridges, buildings and trees all affect range.

Since the "rubber ducky" antenna is so poor, range and communication quality is further limited.

Note that dual FRS and GMRS units cannot have a detachable antenna and requires a license:

- There is one discussion that a license is not required if the GMRS only channels (15-22) are not used.
- There is another discussion that the FCC requires a license for FRS/GMRS units since any channel may be used by the operator.
- There is a third discussion that everyone ignores the FCC GMRS licensing requirements but that is a discussion beyond the scope of this post.

A GMRS license covers your extended family, is good for five years and there is no test for the license. Don't be surprised if the FCC changes or does away with GMRS licensing fees or requirements.

Privacy codes

Use of privacy codes do not make your radio communications private. When you set a privacy code, the radio only allows communications with the same code to come through to your unit's speaker and blocks all others. So if everyone is on privacy code 21, any messages with privacy codes other than 21 are blocked. If there is some stranger within your range who has set their privacy code to 21, they will be able to hear your messages as well as communicate to you. Privacy codes eliminate chatter and are very useful but they are not private.

Poking the FCC bear

You can hack/modify (not legally) the FRS and FRS/GMRS radios so that they have an antenna connector and thus you could wire up an external antenna. There are some tutorials online that instruct in the process. Doing so voids the radio's FCC certification and as such the radio is now illegal to use.

You can also operate without a GMRS license (not legally). Generally, the FCC is not patrolling looking for GMRS offenders. The trouble comes from GMRS licensed users that patrol the airwaves and report offenders.

I'm not making any suggestions one way or another. You have to make your own decisions. BTW ... FCC fines can be hefty.

If you want to read the FCC rules (boring) it can be found here: https://www.gpo.gov/fdsys/pkg/CFR-20...ol5-part95.pdf

Proposal

I propose that the most universal and likely compatible option is GMRS (channels 15 - 22). It is not the best technical option but it most likely will cover what equipment people will bring to the event. There is still the option that some will have FRS only radios (I have four on the desk as I write this) but most units today are dual FRS/GMRS so most can use the GMRS only channels (15-22).

For those willing to put in the effort, a GMRS only radio with a detachable antenna will give improved performance at both ends. Attaching an external antenna will improve performance making it quite usable as groups of cars travel together. If purchasing an antenna, remember that magnetic mounts do not work on stainless steel or fiberglass. Also, the antenna needs a metal ground-plane or counterpoise to operate effectively.

For those willing to spend a few more dollars than for the bubble packs, they can get a better quality radio. Another option is to find Type 95 Certified professional equipment that can be programmed for GMRS frequencies and privacy codes. These radios will be much better built.

If we all agree that GMRS is the band of choice, when we are together we will likely be able to keep in touch via radio. Imagine driving down the road when another DeLorean appears. A quick click of the radio (assuming a standard DeLorean channel and privacy code ... Channel 20 and privacy code 15? (BTTF reference to 2015)) can start the conversation.

[nkemp]

UPDATE:
- Privacy codes may not work amongst differing radio brands. When this happens, code 0 may work.
- FRS/GMRS channels 1 - 7 may allow using high power transmission and require a GMRS license to do so.

[SS Spoiler]

Neat idea Nick, how about some photos of different radio
options in store packaging?


Paul Cerny #2691
Kalispell, MT

[DMCVegas]

Most caravans use FRS, with of course, Channel 12. Pretty much it's been the standard for years.

CB is also still great and quite viable for trail riding or hiking if you need to radio back to the ranger station or to someone else for help. Someone from Europe once had a beautiful bracket they created which used the center bolt of the Rear Screen Upper Finisher. Very nice design. Minimalistic look, and never interfered with the operation of the louvers. As opposed to the spare louvers I got at the junk yard which someone drilled a hole through, and then glued aluminum foil to the underside to try and create a ground plane...

GMRS sounds nice and all, but I don't know that everyone is going to take the time to obtain a license and whatnot. The patrols do appear to be real though. I used to hear allot of chatter over the radio in Vegas about them. Two white Ford Econoline vans traveling in pairs were change trucks for the slot routes. Single vans were patrols believed to be from the FCC or someone else, and always seemed to triangulate the radio shacks of broadcasters. Strange stuff... But that's a whole other story.

[nkemp]

... how about some photos of different radio
options in store packaging?

Google for "FRS/GMRS radio" and you'll get LOTS of photos in the image search or search Amazon.

Here is a link to Amazon: https://www.amazon.com/Midland-GXT10...&keywords=gmrs

And here are some in their retail bubble packs.

Motorola-Walkie-TalkieTwo-Way-Radio-Weatherproof-MU350R1.jpg

[nkemp]

Most caravans use FRS, with of course, Channel 12. Pretty much it's been the standard for years.

We used FRS on the way to DCS16. The downside of FRS is the low wattage output and lack of external antenna results in short range. If you have more than a few cars they need to stay tight so that the front car can communicate to the rear car. Radio Shack's 21-1850 was a good solution to getting the FRS antenna to the outside of the vehicle but they are no longer available new. 5 Watt GMRS improves the range especially with an external antenna.

The Boy Scouts have a rule against caravanning to events to prevent an accident taking out more than one vehicle at a time. A good idea worth considering.

CB is also still great and quite viable for trail riding or hiking if you need to radio back to the ranger station or to someone else for help. Someone from Europe once had a beautiful bracket they created which used the center bolt of the Rear Screen Upper Finisher. Very nice design. Minimalistic look, and never interfered with the operation of the louvers. As opposed to the spare louvers I got at the junk yard which someone drilled a hole through, and then glued aluminum foil to the underside to try and create a ground plane...

If you have the louver brace, it provides another place to mount the antenna and provides two ground radials. Will take a few bends on a bracket to get the antenna to the outside of the lover though. A 1/4 wave GMRS antenna is about 6" for the antenna and radials (of course a 1/2 wave is 12").

GMRS sounds nice and all, but I don't know that everyone is going to take the time to obtain a license and whatnot. The patrols do appear to be real though. I used to hear allot of chatter over the radio in Vegas about them. Two white Ford Econoline vans traveling in pairs were change trucks for the slot routes. Single vans were patrols believed to be from the FCC or someone else, and always seemed to triangulate the radio shacks of broadcasters. Strange stuff... But that's a whole other story.

The FCC recently reduced the fee by $25 and wants to eliminate the fee but GMRS licensed users are opposing the move. Go figure. I did read that the FCC does chase down truckers in violation of GMRS rules and has always done so for pirate ham radio. I agree that most will not get a GMRS license but the effort to get one is really easy. The only test is if your payment bounces. The irritation is that the license fee is more than a pair of radios. The upside is it only takes one license to cover your whole extended family. I suspect the FCC would not agree that the DeLorean community is a "family".

[David T]

Google for "FRS/GMRS radio" and you'll get LOTS of photos in the image search or search Amazon.

Here is a link to Amazon: https://www.amazon.com/Midland-GXT10...&keywords=gmrs

And here are some in their retail bubble packs.

Motorola-Walkie-TalkieTwo-Way-Radio-Weatherproof-MU350R1.jpg

The DMA has been using FBS radios for a long time. It is cheap and you can get them anywhere. Although they have limited range we overcome that by relaying messages back and forth among the caravan. The leaders and followers, to back up communications, also use cell phones. The privacy codes usually won't work among different brands so they have to be set to 0. Of course we use channel 12. The better, more expensive the FBS radio, the better the range, the clarity, and the battery life. CB is pretty much left to only the truckers here in the northeast. All of the other alternatives are more expensive and/or you need licensees and are not readily obtainable. Some have special rechargeable batteries. Most FRS radios use readily available AA or AAA batteries. Some bring extra radios to lend to others in the caravan who either don't have one or forgot to bring one (or their batteries went dead).

[DMCVegas]

The FCC recently reduced the fee by $25 and wants to eliminate the fee but GMRS licensed users are opposing the move. Go figure. I did read that the FCC does chase down truckers in violation of GMRS rules and has always done so for pirate ham radio. I agree that most will not get a GMRS license but the effort to get one is really easy. The only test is if your payment bounces. The irritation is that the license fee is more than a pair of radios. The upside is it only takes one license to cover your whole extended family. I suspect the FCC would not agree that the DeLorean community is a "family".

No, I don't suspect the FCC would allow clubs as all to operate under a single license since they did make it clear that an individual cannot allow employees to utilize one. So they've already got that scenario covered, and I'm sure it applies to organizations as well. However since it is just a fee rather than a test akin to a Radio Amateur license, that does favor things greatly.

Since DeLorean people are very keen on relevant numbers, I'd probably vote for channel 18 since it's "81" backwards if we have a problem with privacy codes.

I'm all for getting out and driving a car. There is no better way to build confidence, and it's just plain fun. Perhaps this is something we start introducing the community to by way of the clubs for both driving tours & caravans, as well as individual driving trips. I'll bring this up at the next DOA meeting as a future consideration.

[nkemp]

Since channels 1-7 are FRS & GMRS and given that the GMRS units can broadcast at higher wattage in the 1-7 channel range, using channels 1-7 may make more sense since it incorporates more units. GMRS is preferred. FRS units would operate at .5W license free and the GMRS handhelds can operate up to 5W (depending on unit).

Feedback I got in a FRS/GMRS specific forum indicates a couple mile range, using 4 Watt commercial quality handheld GMRS, in a vehicle, in the Adirondacks. Using an external antenna should extend the range and/or improve the quality. FRS would likely be in the .5 mile range give or take.

Channels 1-7 may be more congested but that is more likely to occur at a theme park or mall than on a highway.

You don't want to be the last car in the caravan running FRS when you have car trouble. By the time you push the radio's PTT button you'll be out of range.

[Chris4099]

The PNDC group here uses CB. However, the MINI Cooper club I'm with uses FRS, so I'm stuck with two different radios. Since I don't do lots of long caravanning with other D's, I just got a cheap handheld CB for occasional use. Does the job just fine since I'm not long distance from the other Ds.

As for the MINI group, since we go on long drives through twisty back roads, a good radio is critical. This is the most commonly used:
75510XLM.jpg
http://www.westcoastmall.net/midland...na-p-1390.html

As you can see, this has an external antenna with a magnetic base. We can easily get a mile of range in difficult conditions (no line of site with many trees/rocks in between). Now it obviously won't stick to the D's exterior, so I used the luggage rack hinge instead one time. If you don't have that, you'll have to come up with something else (maybe a strong magnet under the louver).

I also recommend getting a headset if you plan to talk a lot. It's a lot easier to simply press a small button clipped to you then to grab and hold a radio to your mouth. Makes it easier to understand the other person as well. Just make sure to disable VOX! That's the work of the Devil right there!