Motorola's 100mw 2.4GHz HTs

[WRQX963]

Does anyone have experience with how they compare to their one-watt 900MHz HTs? How do they compare in thirty-floor buildings, shopping malls, cruise ships with many decks, and absolute range across the Grand Canyon or rooftop to rooftop? What about fancy operational bells and whistles?

[PACNWComms]

If you mean the Motorola DTR2450 handhelds, I have not used these, but have supported many 900 MHz versions in this series of Motorola portables. The DTR410/550/650's in 900 MHz are great. 2.4 GHz may benefit some users, but I tend to stay away from 2.4 GHz myself as I do not wish to raise the WiFi noise floor in my area, and the 900 MHz radios work. Perhaps as they break, they will get replaced with DTR2450's in time?

Here is a video I found online; I do not take credit for any of this video. 

 

 

 

[PACNWComms]

Also found this brochure for those interested. Looks like the DTR 550/650's with a shorter antenna for the 2.4 GHz band. Other features look the same as other DTR series radios, private calls, one to many calls, messaging. Could be useful for some users, barring the line of site issues mentioned in the video. The DTR series radios I have put into place mostly went into schools for campus wide use. The requirements were for unlicensed spectrum radio equipment that would cover about a mile wide campus, and radios that could not be heard with a cheap Radio Shack scanner, as there were concerns about stalkers and people monitoring children getting hurt on the playground, kids wandering off, and just general snooping taking place. If you can set your own hopset like the other DTR series, this can be a very secure method for short range comms. 

dtr2430_dtr2450 Brochure.pdf

[KAF6045]

Interesting -- they show up as DISCONTINUED on the Motorola site (not sure if it was country specific, but the only "unlicensed" radios shown were all European PMR446 units). Only DTRs found are the 600 and 700 models.

[WRQX963]

I just learned that these radios were only authorized for use in the UK, but I could not determine whether their unique frequency hopping pattern would make them unlawful for use on the American 13cm ham band.

[KAF6045]

The ISM band spans 2.4-2.5GHz, Amateur 13cm has snippets in 2.300 to 2.310 GHz, and from 2.390 to 2.450 GHz... So the odds are good that the frequency hopping of an ISM band radio will go outside of the Amateur 13cm band.

US WiFi is not permitted the channels spanning 2456-2495...

[MichaelLAX]

Isn't the frequency hopping controlled by software?

[tweiss3]

Yes, it is software based, but I'm not sure you can select the frequencies you would be using in the hops.

[PACNWComms]

If the frequency hopping is like the DTR410/550/650 series radios, the end user programming the radio is only picking the hopset via a unique code entered into each radio. Radios with the same hopset code in them can talk to one another on that channel. The frequencies are the same but the hopset itself changes. A radio going from hopset frequency 1,6,2,4,9,3 cannot talk to a radio with hopset frequency sequence 6,2,3,1,9,4 for example. 

What I find interesting with the DTR series is that they were often sold as an alternative to FRS/GMRs radios for business use (DTR410/550/650 in 900 MHz ISM band in the United States), but many people kept the default hopset codes that came from the factory. I hear tugboats and construction crews on the default setting often in my part of the Pacific Northwest where UHF comms have been saturated with cheap radios and many users.