Which Devices For Caravanning Communications? (Nextel Direct Talk Or FRS/GMRS)

[JASII]

As posted above, I am wondering what devices people here would choose for simplex communications for vehicle to vehicle caravanning communications. Some family members of mine will be travelling across the country in two vehicles. I have some old Nextels (two i315s, one i580 and two i670s). They are all capable of Direct Talk. I have some 12 volt cords and house chargers, as well. I am inclined to go with these because they should be dead simple for them. Press the PTT (Push To Talk) switch when you want to talk and release when you are done. They get one tone if it goes through and a different sound if they can't connect. I would suggest that they charge them when they are in the vehicle driving and disconnect when they are parked.

One family member said that she has some walkie-talkies. What I don't know is if they are FRS or GMRS. Obviously, I can find out. I strongly suspect that they are the typical "bubble pack" radios commonly available at many retailers. They are likely to be analog and, hopefully, they have some PL or DPL settings, as well.

Anyway, for those that have used portable devices for simplex while caravanning in vehicles, what did you use and how well did it work out? I suspect that there is the possibility of potential interference with FRS/GMRS frequencies, but it shouldn't be a huge concern on a cross-country trip. As far as range goes, I am hoping that Direct Talk would be solid, vehicle to vehicle, for half a mile.

Anyway, lets hear it. What would you go with and why? Keep in mind that I want to keep it simple. No external antennas. I have pretty much ruled out MURS because I think the 2 watt VHF signal might be attenuated too much inside a vehicle.

 

[chief21]

I have no experience with Nextel Direct Talk, but I expect that the best range might be achieved by using the MURS radios with simple quarter-wave whip antennas on small mag mounts.

 

[N4KVE]

I used direct talk. It’s secure so strangers can not monitor you. Besides those Nextel phones were MUCH better quality than a $10 FRS radio.

 

[MTS2000des]

The Motorola r765 is the top tier iDEN handset, and the last to leave the building. Now that SouthernLINC has migrated to LTE, these are plentiful. They use the same accessory connector as the Pro series radios, and charge in Pro series chargers. Direct Talk capable (Southern Linc firmware refers to this as "LINC around"). You'll need some kind of SIM card installed to use them on DT (obviously doesn't have to be active, just one that the radio will recognize).

Has a removable high gain antenna and some of the best performance of any iDEN handset made.

 

[JASII]

...You'll need some kind of SIM card installed to use them on DT (obviously doesn't have to be active, just one that the radio will recognize)...

Thank you very much for the reply. I didn't realize that other kinds of SIM card would work. That is great to know.

I have eyed these up in the past, but I simply haven't bought any, yet. I also recall that there are both an "IS" version and a "regular" version. If I recall correctly, the IS version is only 600 mW and the regular is 1 watt. However, with iDen, the difference in range might be small.

 

[n1das]

Thank you very much for the reply. I didn't realize that other kinds of SIM card would work. That is great to know.

I have eyed these up in the past, but I simply haven't bought any, yet. I also recall that there are both an "IS" version and a "regular" version. If I recall correctly, the IS version is only 600 mW and the regular is 1 watt. However, with iDen, the difference in range might be small.

I don't think just any SIM card will work. I think it has to be a SIM card from NEXTEL or another iDEN carrier and has to have been activated once on an iDEN network. DT mode in DT capable iDEN handsets and the Motorola DTR and DLR series radios have an 11-digit Private ID as a hardware electronic serial number (ESN) because it is an ID based system. Activating a SIM card for a DT capable iDEN handset provides an area code and phone number to use on an iDEN network. The 11-digit Private ID to use in DT mode is formed from 1 plus the area code and phone number. This is why a previously activated SIM card is required to enable DT mode in DT capable iDEN handsets. A SIM card from a non-iDEN carrier *might* work if the area code and phone number are stored in the same location in the SIM card. I don't know for sure, never tried it.

DT mode in iDEN handsets use the old MOTOTALK platform. The Motorola DTR series (DTR 410/550/650 and new DTR 600/700) and the Motorola DLR series also use the MOTOTALK platform but they were purposely coded differently and are incompatible with DT mode but it is the same FHSS digital system. Anyone familiar with the performance of the DTR and DLR series radios will find DT mode's performance in DT-capable iDEN handsets to be identical to the DTRs and DLRs. I have used DT mode in my i355 NEXTEL phones my wife and I had years ago and that's when I first learned of the DTRs when they first hit the market in 2006. The i355 transmits at 890mW in DT mode, identical to the DTR 410/550/650 radios.

I suspect the DT mode in iDEN handsets was an early implementation of MOTOTALK. The DTR 410/550/650 radios were a spinoff from the DT feature in DT capable iDEN handsets. Adding features to the DTRs is where the DTRs became incompatible with DT mode but they still use the same MOTOTALK platform underneath. The latest version of MOTOTALK is in the DTR 600/700 and DLR 1020/1060 radios.

MOTO Talk - Wikipedia

en.wikipedia.org

 

[n1das]

As posted above, I am wondering what devices people here would choose for simplex communications for vehicle to vehicle caravanning communications. Some family members of mine will be travelling across the country in two vehicles. I have some old Nextels (two i315s, one i580 and two i670s). They are all capable of Direct Talk. I have some 12 volt cords and house chargers, as well. I am inclined to go with these because they should be dead simple for them. Press the PTT (Push To Talk) switch when you want to talk and release when you are done. They get one tone if it goes through and a different sound if they can't connect. I would suggest that they charge them when they are in the vehicle driving and disconnect when they are parked.

One family member said that she has some walkie-talkies. What I don't know is if they are FRS or GMRS. Obviously, I can find out. I strongly suspect that they are the typical "bubble pack" radios commonly available at many retailers. They are likely to be analog and, hopefully, they have some PL or DPL settings, as well.

Anyway, for those that have used portable devices for simplex while caravanning in vehicles, what did you use and how well did it work out? I suspect that there is the possibility of potential interference with FRS/GMRS frequencies, but it shouldn't be a huge concern on a cross-country trip. As far as range goes, I am hoping that Direct Talk would be solid, vehicle to vehicle, for half a mile.

Anyway, lets hear it. What would you go with and why? Keep in mind that I want to keep it simple. No external antennas. I have pretty much ruled out MURS because I think the 2 watt VHF signal might be attenuated too much inside a vehicle.

DirectTalk (DT) mode is the way to go. GMRS/FRS bubble packs, meh.

LOL, you know me and my choice is the Motorola DTRs because I already own two fleets of them (DTR700 and DTR650). They work excellent and have worked better than 4W GMRS portables on simplex. Coverage inside buildings is where they blow everything else away operating on simplex. People using DTRs aboard cruise ships have reported having full ship coverage on all decks whereas a pair of 4W UHF Part 90/95 portables on GMRS had trouble penetrating more than about 2 decks.

The DTRs are my digital replacement for GMRS/FRS for my local on-site simplex type use with family and friends. A coworker once asked me why not just use FRS? My answer was that I have already been doing that since FRS was created in 1996 and longer than that as a GMRS licensee since 1992 and using good Part 90/95 commercial gear. I want a secure, all-digital solution that is higher quality and more professional than FRS. Being able to make them very secure and not having to worry about FCC licensing and frequency coordination issues are bonuses. I still have GMRS/FRS as a backup and for interoperability with conventional radio (non-DTR) users but they are no longer my default go-to mode for local on-site simplex type use.

Your old NEXTEL phones operating in DT mode should perform identical to the DTRs. You should have solid vehicle to vehicle coverage for a half a mile or more, unless something is in the way which at this point GMRS/FRS bubble packs will already be useless too. DT mode will outperform GMRS/FRS bubble packs like the DTRs do.

 

[bharvey2]

I've used GMRS radio quite a bit for car to car transmissions. I use commercial gear not bubble pack. Even with some old Maxon HTs with 12V adapters, external mics and standard duck antennas, I was good for 1/2 mile separation. Using an external antenna adds a lot more distance. I've used the IDEN talk around feature but never in a car so no experience there.

 

[n1das]

BTDT too many times on GMRS with commercial gear, not bubble packs. 1/2 mile separation, no problem. That was before I learned about the DTRs and started using them instead of GMRS for local simplex ops.

 

[JASII]

N1DAS,


Is there a true "car cord" for the R765s or do I have to go with what looks like a so-called travel charger?


Jim

 

[Firekite]

No external antennas. I have pretty much ruled out MURS because I think the 2 watt VHF signal might be attenuated too much inside a vehicle.

Why no external antennas? Even just a cheap 1/4 wave mag mount would do wonders on the roof. What’s your budget, by the way, and how much of a stickler are you about FCC rules?

 

[JASII]

Why no external antennas? Even just a cheap 1/4 wave mag mount would do wonders on the roof. What’s your budget, by the way, and how much of a stickler are you about FCC rules?

It is for my mother-in-law, sister-in-law and brother-in-law. I need to keep it dead simple. Like simply turn it on or off and talk.

 

[n1das]

N1DAS,


Is there a true "car cord" for the R765s or do I have to go with what looks like a so-called travel charger?


Jim

I don't know what the R765 has for a connector on the bottom. If the R765 has the same wide connector like the DTR 410/550/650 radios, car chargers that plug into the cig lighter socket I think are still available for them. DT capable NEXTEL phones share a common design with the DTR series radios since they were a spinoff from the DT feature. I was digging around in my basement a few months ago and found a mobile charger for my old i355 NEXTEL phones from 10+ years ago. It works with my DTR650 radios.

 

[JASII]

It looks like the legacy Nextel power cords will not work.




It

 

[JASII]

My two i315s have had it, though. The little piece over the PTT switch literally fell off both of them a couple of days ago!

 

[JASII]

BTDT too many times on GMRS with commercial gear, not bubble packs. 1/2 mile separation, no problem. That was before I learned about the DTRs and started using them instead of GMRS for local simplex ops.

N1DAS (And The Group),

I was speaking with a fellow amateur radio operator recently. We are planning on doing some testing soon. He will remain at his apartment with one R765 and one 4 watt DMR portable on UHF. Both will use OEM rubber duck antennas. I will then drive away, in my pickup, using similar radios. I will have an automotive GPS, so I can easily see how far away I am from his location. At say every tenth of a mile I will check to see if we can communicate. The R765 should be easy, since I get different noises if the call connects vs. not connecting.

I am anticipating that somewhere between .5 and .7 miles the R765 should be solid. How far will the 4 watt UHF DMR radios be able to communicate? Will their range be longer of shorter than the R765?

Jim

 

[Firekite]

Rather than remain in his apartment, why not have him sit in his running vehicle? Seems like a much closer approximation to the scenario you’re actually looking for.

 

[JASII]

...why not have him sit in his running vehicle?...

Because he is physically handicapped and spends virtually all of his waking moments in a power wheel chair. He doesn't own a vehicle and relies pretty much on public transportation.

You are correct, though, if he were in a vehicle it would be a closer approximation to the scenario I am trying to replicate.

 

[JASII]

N1DAS (And The Group),


I bought some old R765s and I want some new batteries. The current batteries show Motorola PMNN4087A Li-Ion Battery 1010mAh. I have poked around a little bit, but I haven't found anything other than the standard battery for this. Is there, or was there, ever a battery made with more capacity than 1010mAh?

The lowest price I have found so far is $78.71 from Radio Parts. Are they a reputable dealer? Also, I recall going to hamfests years ago and some places would rebuild battery packs. I never have done that. Is it a good option? Is it better quality or more reasonably priced?


Two-Way Radios, Replacement Parts & Accessories - Radioparts

Motorola PMNN4087A Li-Ion Battery - OEM Batteries - Batteries - Accessories - Two-Way Radio Equipment - Radioparts

 

[JASII]

One other thing, my mother-in-law now wants to use these. If I give them to her and they stay powered up, how often will she need to charge these? I can tell her to just watch the battery indicator, but if I can give her an approximation, it would be helpful. To keep it even more simple, I am going to sent drop in charger to her and two R765s. I think if she were to charger one up, over night, and then the other the next night, that should be way more than enough to keep them "topped off".

Is it okay to have then powered up while they are in the drop in charger?