What Would You Choose For Car To Car Simplex Communications?

[JASII]

We already had some great posts in the GMRS/FRS/MURS thread about legal, license free (or easy to obtain license like GMRS).


This time lets assume all involved are licensed Amateur Radio Operators operating in the United States. What would you select for car-to-car simplex communications on a device with a rubber duck antenna in a vehicle? For can select whatever band AND voice mode you want. For example, if you want 902-928 APCO P25 you can. Or, if you want 1.2 GHz analog FM, you can say that.


Again, change it up to a band and a voice mode for car-to-car simplex with the ability to use a mobile antenna. Would you go 6 meters analog FM? Would you prefer a digital voice mode?

 

[Omega-TI]

A rubber duck on 6? Forget it. Even with a mobile antenna on the calling frequency of 52.525 you"ll find very little activity unless the band has an opening. I'd go with 2 meters, even though there is much less activity than 10 years ago, it should give you more bang for the buck and will be okay with a rubber duck, although a mobile antenna with the car as a groundplain will give you better performance.

 

[kb5udf]

Given your specification of rubber duck in vehicle in the ham bands, I'd go with 2m or 70cm (144/440) radios. The band most effective may depend on the vehicles involved since in my experience 2m takes a big hit in vehicles with less window area and more metal. This is not to say 2m is un-usable, just that in some vehicles the faraday cage effect is worse than others. While 220mhz band might be ideal I have no experience in this band, but I suspect it would be a great compromise.

 

[paulears]

I'm not being funny here, but if the vehicles are all containing ham operators, then dual band radios would probably be something they'd all already have, and they'd simply pick a few frequencies in both bands and use whichever worked best where they were operating. I doubt that any other bands would make any sense at all - nobody tends to have 6m portables (a bit pointless buying them as there's nobody the other end!) and higher bands suffer from too much attenuation, and again - few hams have them as they're rarely much use? If you want range, then dump the inefficient antennas and use one on the vehicle - but every ham knows this anyway? I'm struggling to find the purpose in the question? Every ham surely knows the answers to this one. comms from portables inside a partial Faraday Cage are unpredictable and rarely have any kind of distance element. You could happily go digital but again, this is a kit decision and not really relevant. Create the best path, and pick equipment to do the job. Very often it's just asking the participants what they have available?

 

[W8HDU]

Again, change it up to a band and a voice mode for car-to-car simplex with the ability to use a mobile antenna. Would you go 6 meters analog FM? Would you prefer a digital voice mode?

I'm probably the exception to most here, but I use mobile to mobile comms a lot. Our radio of choice is VHF-High Band. It offers the most punch considering we can be in a caravan down the highway, or approaching a job site and getting "talked in", or if we need to coordinate with someone else in the field. Now, there is a caveat.

If all you want is car to car comms, and you're within a mile, a cheap UHF Baofeng will work. If you need range, then a good mobile antenna is needed. By "good", I'm not talking about something cheap and small. You need a good 5/8th over 5/8th to get some gain.

For me VHF High works well. There are not a lot of users on the band, so crowding is no issue. It works equally well on the highway, across farm fields, and water. Metro is does the best considering all the big buildings.

Where VHF High and UHF doesn't work is among the trees and woods. I have several locations I go where we have to use Low Band. The absorption in wooded areas cuts the range, but good ol Low Band works.

All my radios are DCS toned, licenses. License free is OK, and works for the most part, but occasionally you get a jakask who wants to talk over you or talk to you. I've not had a problem in the last 13 years since getting licensed radios with tone.

Some here may have a simpler, cheaper way, without the demands of good comms. I have to have good comms as time is money, and coordination of crew is needed for efficiency.

 

[ladn]

I'm an avid 4WD (4 wheel drive) user and licensed ham. Years ago, most of my buddies and I switched from CB to ham radio and never looked back.

We usually use VHF because we've found it tends to work better in the terrain we encounter. I have a mobile in my vehicle with external antenna (either NMO 2/70 or 1/4 wave vhf) and a rubber duckie HT when I'm out of the vehicle.

Some of my friends have only their rubber duckie HT in the vehicle. When we're relatively close, these work just fine, but many times their signals fade out over distance, but they can hear those of us with mobile rigs and external antennas.

We usually run carrier squelch (no PL/DPL).

I used to lead commercial 4WD tours. We used CB for primary communications, but my partner and I (and sometime a few clients) had 2M ham radio for secondary coms. Our clients provided their own radios and vehicles. Most had conventional CB's with external antennas, but every once in awhile someone would bring a CB handheld with just the rubber duckie. CB was borderline adequate. It worked well for those with decent quality radios and installations, but was fairly worthless for those with just the duckie inside their vehicle. Our biggest problem was when the skip started to come in (especially in the afternoons). We always used Channel 1, and there was this one guy, "audio man", who's high powered monologue consisted of "heloooo--audiooooo, audiooooo..."

 

[W8HDU]

... snip ... We used CB for primary communications, but my partner and I (and sometime a few clients) had 2M ham radio for secondary coms. Our clients provided their own radios and vehicles. Most had conventional CB's with external antennas, but every once in awhile someone would bring a CB handheld with just the rubber duckie. CB was borderline adequate.

We'll use CB Channel 4 (AM) if we're driving the logging roads, or over at Drummond Island, or the dunes. If we're topping hills or coming around blind corners we'll announce ourselves. And there are usually enough itinerant handhelds for backup if someone gets into trouble.

I'm not sure where the guy got it, but one fellow had a CB which plugged into the cigarette lighter, and the handset was the radio with a rubber duck on the mic. Tried to explain why it was not working most of the time, but he said the box it came in said "10 miles or more". I couldn't hear him at 1/4 mile.

 

[K6GBW]

VHF from a handheld, inside a car, does not work well. The wave length is attenuated by the vehicle. 440, on the other hand, works fairly well. When I was still working my department used VHF up until 1998. We switched to UHF and the hand held worked much better from inside the cars.

 

[El_Kabong]

Gotta agree re 70cm

Seldom use 2m anymore

 

[kk9h]

For many years I have been driving to Dayton with friends who are all hams. We have experimented with 2M, 220, 440 and even 900 MHz. 2M has proven to be the most successful for reliable communications on the interstate and around the Dayton area. 220 is a very close second, but the lack of available equipment makes 2M more universal and practical. With a 50 watt radio and a roof mounted 1/4 wave antenna, 7-10 mi. and sometimes more is not unusual range when we get spread out. In fact, last year one of our group was just leaving the Xenia fairgrounds and we heard him by our hotel in Miamisburg which I though was really good for simplex. 5/8 wave antennas help some, but they don’t provide a huge improvement over roof mounted 1/4 wave antennas. Magnet mounts are just fine. So for the last 20+ years, 2M (or VHF-hi if you will) has proven to be an ideal band for travelling groups. Add PL or DPL if you think you need to and you will have a nice reliable group simplex radio system.

 

[PACNWDude]

Last month I had to pleasure to essentially be the convoy commander of a contracted team to replace some microwave gear on a mountaintop covered in light snow and ice. The contractors were from a local radio shop, had gear on the next mountain over, yet lacked any mobile comms for vehicle-to-vehicle use in the four vehicles they showed up with.

Halfway up the mountain (in the lead vehicle) I lose sight of the rear vehicle, then the one in front of that. Luckily, me and my own crew had some MURS radios (VHF) which were distributed to one person in each of five vehicles as I walked back to check on what was happening. The last vehicle got stuck in snow and ice, as the driver had not engaged four-wheel drive yet. The vehicle in front of them stopped to help out. That rear vehicle had to be left behind as even in four wheel drive the tires were street rated only. So now four vehicles have comms. The driver on my crew was now in a hurry, and we managed to get about a mile within a pine forest ahead of the rear (fourth) vehicle. The MURS five-watt radios worked very well within that distance. We could not test further as I did not want to get too much further away from the other vehicles. I know the distance between vehicles as a certain government agency thought it odd that five white vehicles were heading up a mountain so late into the snow season. They provided me with the distances and where we were transmitting. Seems they monitor MURS/FRS/GMRS and 2-meter amateur for lost hikers often, and even have some direction-finding gear on this particular mountain.

My note to self, always keep a few spare radios to give to other vehicle users in your convoy. Whether amateur, FRS or GMRS or something else, anything is better than nothing.

For my own personal use, when with family we tend to use the 1-watt DTR series 900 MHz ISM band Motorola radios, which get you about one mile range. I frequent ski resorts where everyone seems to have FRS/GMRS and getting a clear channel can be rough. DTR keeps only my crew on the "net" and gives enough range for our needs.

Good luck on whatever you decide to use.

 

[N4JKD]

Car to car, 2 meter simplex hands down. The most reliable that you will find for close clear communications. I say that because VHF works in places in my area, where even cellphones have no signal, but there is a 2 meter repeater in that area and lots of people there have their ham ticket and more people are getting their tickets every day.

 

[N4KVE]

I have a box of MOTO XPR6580’s. I paid like $50 each. 800/900 MHz. And while VHF/UHF might give more range, I’ve never had a problem as long as every car stays within a half mile. And I’ve never had a situation where I’ve heard any other station, or even seen the RX light come on For anyone else.

 

[jaspence]

Those that receive on 800 MHz could cause you problems in some states if you were stopped for some reason. A ham license will get you by with the 900 frequencies.

 

[N4KVE]

Those that receive on 800 MHz could cause you problems in some states if you were stopped for some reason. A ham license will get you by with the 900 frequencies.

Since this in the ham radio general discussion I figured we were all hams. The ham license gets you by on all frequencies at least here in Florida.

 

[sallen07]

Since this in the ham radio general discussion I figured we were all hams. The ham license gets you by on all frequencies at least here in Florida.

Huh? So in Florida you are allowed to use any frequency, as long as you are a ham?

I don't think so.

 

[N4KVE]

Huh? So in Florida you are allowed to use any frequency, as long as you are a ham?

I don't think so.

Yes, we can use any frequency we want. We just can not transmit on any frequency. Having a scanner in a car is illegal. But if I get pulled over listening to the West Palm PD on a scanner, or other listening device, by having a ham radio license means there’s nothing the cop can do. But on my 6580’s there’s a lot of real estate between 902, & 928 for hams to use.

 

[sallen07]

Yes, we can use any frequency we want. We just can not transmit on any frequency.

Ah. In my mind "use" means "transmit on", not "listen to".

I thought you were asserting that you could transmit using those radios on any 800 or 900 MHz frequency.

 

[Rt169Radio]

Car to car, 2 meter simplex hands down. The most reliable that you will find for close clear communications. I say that because VHF works in places in my area, where even cellphones have no signal, but there is a 2 meter repeater in that area and lots of people there have their ham ticket and more people are getting their tickets every day.

I agree, 2 meter simplex has a good history of working well without needing anything fancy.

 

[ab3a]

Depending on terrain, you may also consider 50 MHz SSB. Yes, the antenna is bigger, but it can cover a lot of territory. I know this because I used to work for a water utility and we had licensed frequencies on 44 and 48 MHz. Our radios were 100 watt simplex models. It worked pretty well. The great thing about it is that it requires minimal other infrastructure. I was able to talk to our headquarters in Laurel Maryland from the Eastern Shore, From all the way north in New Jersey and all the way south from Richmond Virginia. And that's basically groundwave, not skip.

I would think something similar could work for you on Six Meters, as long as you don't mind the larger antenna.