Retevis 900MHz License Free Two Way Radio, license-free 900 MHz ISM (Industrial, Scientific and Medical) band.
I found this interesting radio while surfing Retevis' site. Not sure what to make of it yet.
Wow!!! I haven't seen 49 MHz in probably 20 years or more.
It's funny how people are always obsessed with getting "X" miles of range out of a pair of radios while range as you know depends on multiple factors. 1W (+30dBm) is the FCC Part 15 legal limit for a frequency hopping spread spectrum (FHSS) device operating under FCC 15.247 in the 902-928MHz band. The Part 15 legal limit for a non-frequency hopping device in the 900MHz band is 1 mW (0 dBm), IIRC.Only one watt on 900 MHz, that's not going to get you very far.
I'm guessing about possibly a mile and be somewhat reliable? Maybe 1.5 under really good conditions.
I can echo this. I bought a set of DLR1020's specifically for use on a cruise, and it was one of the best radio investments I've made and they have become our primary radios around the neighborhood too. If you're measuring range as true line of sight, perhaps 1 watt FHSS at 900 MHz isn't your best solution. But if by "range" you mean how many building floors it can penetrate, or whether it can get out of the third sub basement, then two buildings over, then back into a sub basement in the neighboring building, 1 watt of FHSS at 900 MHz will blow any 150 MHz/450 MHz analog or DMR radio out of the water.Motorola DTRs on 900MHz are capable of outperforming VHF and UHF conventional portables on simplex. Where the DTRs beat VHF and UHF conventional portables is when operating inside buildings due to buildings being much more open at 900MHz compared to 150MHz and 450MHz. Where the 900MHz DTRs blow all others away on simplex is when operating aboard cruise ships. People who have used DTRs aboard cruise ships report having full ship coverage on all decks compared to a pair of 4W UHF portables on GMRS simplex which had trouble penetrating more than about 2 decks. When operating aboard a cruise ship, you are essentially operating inside a compartmentalized metal box. The shorter wavelength signals at 900MHz reflect in an out of the many nooks and crannies of the ship where longer wavelength signals at VHF and UHF won't. The many reflections actually help with the FHSS operation because individual hot spots and dead spots also hop around as the frequency hops. The FHSS operation effectively stirs the modes so to speak.
This is exactly why the Retevis radio caught my attention. If it is legit and is compatible with the DTRs and DLRs, that would be cool too. Motorola has been keeping the DTR/DLR protocol close to the vest for a long time but if they work with the DTRs/DLRs, it could be a sign that Motorola has finally opened the protocol up to the world to help grow the market.I have no idea whether this Retevis radio is legit. But given how well Motorola DLR and DTR radios work - how much better they work than conventional analog and digital radios for many applications - it would be great to see more manufacturers make use of unlicensed 900 MHz FHSS technology.
I would be beyond shocked (and that's putting it mildly) if Motorola is or does anything to aid competition and compatibility with the DTR/DLR series. My best hope has been that another manufacturer will see the benefits of 900 MHz FHSS technology and develop a product line that operates in that way, but I would never dream that they would be compatible with DTR/DLRs.This is exactly why the Retevis radio caught my attention. If it is legit and is compatible with the DTRs and DLRs, that would be cool too. Motorola has been keeping the DTR/DLR protocol close to the vest for a long time but if they work with the DTRs/DLRs, it could be a sign that Motorola has finally opened the protocol up to the world to help grow the market.
This radio is not real. It is VAPORWARE. Retevis put some specs on their website but they are not for this radio at all. There are a number of red flags all over the place. It resembles a hilarious copy and paste job from multiple sources. Can you spot them all? (LOL) I copied and pasted the specs below.
902.525 - 927.475 MHz
30/50CH (up to 200)
(No including antenna)
4FSK digital modulation
12.5KHz for data:7K60FXD 12.5KHz for data and voice :7K60FXE
Rated audio Distortion
Max Frequency Stability
Sensitivity (12dB SINAD)
Analog 25K≤-121dB 12.5K≤-119dB
25K≥45 dB 12.5K≥40dB
Adjacent channel selectivity
25K≥65 dB 12.5K≥60dB
Intermediation (Wide/ narrow)
25K≥60 dB 12.5K≥55dB
Spurious Response Rejection
Battery life under 5-5-90duty
14.8 hours(with 1600mAh Li-ion battery)
20.9 hours(with 1600mAh Li-ion battery)
I guess someone either thought they could cut'n'paste and it would be 'close enough', or they really thought people would buy it and not know the difference.
Yet another reason I do not waste my money on these low tier radios.
Replacement batteries are still readily available if you have a bunch of these phones and want to keep them going. I recently re-batteried my DTR650 fleet with factory fresh new batteries and they use the same battery.One could pick up a pair of Nextel phones that could do “Direct Talk” between each other. It’s a similar 900 frequency hopping” mode, & they work real well.