Motorola DTR 550 Or DMR UHF Simplex On A Cruise Ship?

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#1
I currently have a pair of Motorola DTR550s and one UHF DMR radio that will transmit 4 watts on 70 cm. Both my wife and I are licensed amateur radio operators. I am just curious if people here think a DTR550 or DMR radio would have better simplex coverage aboard a ship?
 
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#2
I have used GMRS with good Part 90/95 commercial gear on a cruise a couple of years ago. My experience matches others who have found it a challenge to communicate more than 1 or 2 decks above or below your location while the other person is at the opposite end of the ship. One thing I found that helped was to go to the nearest elevator lobby. The elevator lobby and elevator shafts are open to most decks on the ship.

People have also tried using the DTRs under the same conditions aboard a cruise ship and they worked perfectly and everywhere throughout the ship. Like with buildings, the cruise ship will be much more "open" at 900MHz compared to 70cm so penetration should be better.

I say go with the DTRs. That's my plan for if and when I go on another cruise someday.

Good luck.
 
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#3
DTR.

I took a pair of them aboard Carnival and Norwegian ships and had complete ship coverage.

They were the gen 2 models with the shorter whip, not the original style stub antenna.

Past experience using 4W UHF radios on cruise ships resulted in the signal breaking up once separated by a few decks.

I was very impressed with the DTR's performance.

Using them around town, they're not impressive. Aboard a cruise ship- they're awesome.
 
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#4
DTR.

I took a pair of them aboard Carnival and Norwegian ships and had complete ship coverage.

They were the gen 2 models with the shorter whip, not the original style stub antenna.

Past experience using 4W UHF radios on cruise ships resulted in the signal breaking up once separated by a few decks.

I was very impressed with the DTR's performance.

Using them around town, they're not impressive. Aboard a cruise ship- they're awesome.
I bought the longer 7" whip to use with my DTR650s.
 

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#5
I have DTR410's with the short fixed antennas, they work very well aboard vessels.
Only issue was noise in the engine room for users down there. Headsets are needed in high noise areas. If you are a passenger on a cruise ship, DTR will work great.

Many cruise ships use DMR, so best to do DTR so you do not have any chance of interfering with them.
 
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#11
I have used GMRS with good Part 90/95 commercial gear on a cruise a couple of years ago. My experience matches others who have found it a challenge to communicate more than 1 or 2 decks above or below your location while the other person is at the opposite end of the ship. One thing I found that helped was to go to the nearest elevator lobby. The elevator lobby and elevator shafts are open to most decks on the ship.

People have also tried using the DTRs under the same conditions aboard a cruise ship and they worked perfectly and everywhere throughout the ship. Like with buildings, the cruise ship will be much more "open" at 900MHz compared to 70cm so penetration should be better.

I say go with the DTRs. That's my plan for if and when I go on another cruise someday.

Good luck.
DTR audio test:
https://www.youtube.com/watch?v=aaNdMWPmVZI
 
Joined
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#12
I have a pair of 900mhz motorola GTX walkie talkies that run 4 watts of analog fm and they easily put those 1 watt digital radios to shame and they were 80 dollars for the pair on ebay

And yes, without exception, conventional analog radios will ALWAYS out distance digital
 
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#13
I have a pair of 900mhz motorola GTX walkie talkies that run 4 watts of analog fm and they easily put those 1 watt digital radios to shame and they were 80 dollars for the pair on ebay

And yes, without exception, conventional analog radios will ALWAYS out distance digital
You're aware that your 900MHz Moto GTX portables are not legal to use on the 902-928MHz band without a ham license, right?

You're aware that your 900MHz Moto GTX portables are not legal to use on 900MHz commercial systems in the 935-941MHz range unless you're the licensee or an authorized user of such systems under someone else's license, right?

I am familliar with other radios on 900MHz besides the Motorola DTRs and DLRs. As a licensed ham, I own a Motorola MTX9250 handheld that I use for amateur radio on the 902-928MHz band. It works great and I've used several of the 900MHz regional coverage ham repeaters in my area. The MTX9250 is used for a very different purpose than the DTRs. And it's not all about distance alone.

One thing that helps the 900MHz DTRs aboard a cruise ship are the reflections and multipath effects while operating deep inside the ship. The reflections and multipath effects combined with FHSS operation can actually help with coverage. With a DTR radio in a given location, a hot spot for reception for example at say 902MHz may be a dead spot at 927MHz. For any given location of the radio, the hot spots and dead spots essentially hop around as the frequencies hop due to the FHSS. An occasional individual hop may be in a dead spot and a small amount of data may be lost but with digital you have the benefit of forward error correction (FEC) to help out. Dead spots will effectively be much less of an issue as the radio is moved around. You don't have these benefits with an analog radio operating on a single frequency.

Your higher powered analog radios on 900MHz require licensing which the DTRs don't. They are easily monitored and easily jammed, of which the DTRs are much more immune to both. Your analog radios suffer from all of the limitations of plain old analog radios. While not encrypted, the DTRs can be made very secure through private 1 to 1 and private group calling. Short of the government and/or using proprietary Motorola DTR test equipment, the DTRs are practically un-monitorable. There is no scanner available that can monitor them and it's unlikely that there ever will be in the future. The DTRs are also very immune to jamming due to the FHSS operation. With FHSS they can coexist with other transmitters operating simultaneously in the 902-928MHz band including other DTRs and DLRs operating in the same local area.

While your 900MHz handhelds have a little more Tx power, they have inherent limitations which the DTRs overcome with them being digital (VSELP) and using FHSS.

Have fun! :)
 
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#14
And yes, without exception, conventional analog radios will ALWAYS out distance digital

Can't say I've ever seen it be the case always. I've seen some digital modes under perform to 5 kHz analog. I've seen some over perform. Depends on the mode. Also seen many receivers/DSP's be more selective when working with digital signals compared to analog and able to work more efficiently with weaker signals.


Sent from my iPhone using Tapatalk
 
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#15
DTR radios work just fine

I currently have a pair of Motorola DTR550s and one UHF DMR radio that will transmit 4 watts on 70 cm. Both my wife and I are licensed amateur radio operators. I am just curious if people here think a DTR550 or DMR radio would have better simplex coverage aboard a ship?
I agree with the others on using the DTR radios on a cruise ship. I don't think I went below deck 5 but it they worked great everywhere we went. Digital is amazing.
 
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#16
I agree with the others on using the DTR radios on a cruise ship. I don't think I went below deck 5 but it they worked great everywhere we went. Digital is amazing.
It's the combination of 900MHz, VSELP digital (8-level FSK), and FHSS that is amazing and enables them to work so well. Motorola has a real gem of a product IMHO of which the technology has been very under-utilized and under-appreciated. They work amazingly well for their intended use.

With the addition of the DLR models (DLR1020 and DLR1060), Motorola appears to be committed to keeping the DTRs and DLRs on the market. The DTRs have been on the market for 10 years now and have hardly changed at all and still are current product and don't really need to change. The DTRs were ahead of their time 10 years ago. Amazing. :)
 
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#17
DMR UHF

I currently have a pair of Motorola DTR550s and one UHF DMR radio that will transmit 4 watts on 70 cm. Both my wife and I are licensed amateur radio operators. I am just curious if people here think a DTR550 or DMR radio would have better simplex coverage aboard a ship?
I have used both in a cruise ship, about the same coverage, not 100% but better than any analog UHF radio.
My DMR UHF is a TYT MD-380, set on SX. I prefer the 380.
 
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#18
I have used the Midland GXT1000 on ships with good results. We had very goos coverage. At one point my wife was on deck 1 midship, on the Zuiderdam at the front desk, and I was on deck 9 aft. I was able to talk to her just fine. Despite also owning the Tera TR-505s as well, I find the Midlands to be very good for situations like cruise ships. The midlands perform better than the Motorola 350s we tried. They got sent back.
 

alcahuete

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#19
In my experience, the DTRs will outperform anything hands down on cruise ships, and I have done some very extensive testing. My 650s are the only radios with which I was ever able to achieve 100% full ship coverage.

On my last cruise, I was in the theater (deep bow) waiting for a shore excursion, talking to family members outside the ship. Crystal clear. The Cruise Director actually came up to me and asked me what kind of radio I was using, as his radio (UHF simplex) broadcasting basically to the exact same location off-ship was completely broken 80% of the time. He was blown away. Not sure why they weren't using a repeater, but oh well.
 
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#20
digital

In my experience, the DTRs will outperform anything hands down on cruise ships, and I have done some very extensive testing. My 650s are the only radios with which I was ever able to achieve 100% full ship coverage.

On my last cruise, I was in the theater (deep bow) waiting for a shore excursion, talking to family members outside the ship. Crystal clear. The Cruise Director actually came up to me and asked me what kind of radio I was using, as his radio (UHF simplex) broadcasting basically to the exact same location off-ship was completely broken 80% of the time. He was blown away. Not sure why they weren't using a repeater, but oh well.
Crew member radio was probably analog. Using DTR or DLR radios have the advantage of being digital and 900Mhz, in a heavily steel walls and floors environment, 900mhz is the best as long as you have windows.
 
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