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Odd ball radio services?


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#1 Lscott

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Posted 30 January 2021 - 07:26 PM

Other countries have their versions of VHF and UHF radio services. Anybody bump into them being used in the US or had experience using them? https://en.wikipedia.org/wiki/PMR446 https://radioaficion.com/news/new-channels-pmr446/ https://www.hfunderground.com/wiki/index.php/245_MHz_VHF_CB https://www.hfunderground.com/wiki/index.php/Freenet https://radiofreeq.wordpress.com/2018/08/30/canada-vhf-ladd-channel-list/#more-1675

#2 SUPERG900

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Posted 30 January 2021 - 07:56 PM

Wouldn't exactly be legal here as Hams would be all over up in arms.

As they're somewhat based on DMR they have a lot of potential, but they are limited to 500mw



#3 Lscott

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Posted 30 January 2021 - 10:18 PM

I’m curious how many of these radios have shown up in the US by people coming for business or vacations. The PMR446 and dPMR446 radios would end up on the Ham 70cm band. The German FreeNet radios are just above the Ham 2M band. And the radios from Singapore operate between the Ham 1.25M band and the military frequencies around 300MHz. Traveling in the western part of Canada in the back woods using the VHF resource road frequencies seems mandatory. The frequencies are posted which ones to use on the roads. A comment in the article about modified VHF radios, I assume Ham gear, is typically used. https://radiofreeq.w...list/#more-1675 If those frequencies are used in Canada there is a chance they could be used in the US as well. I wonder if anybody had monitored communications on those frequencies that didn’t sound like business, public safety etc.

#4 kb2ztx

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Posted 31 January 2021 - 07:46 AM

Im sure there are various radios but you will see a ton of ICOM LMR radios in Canada. When I did LMR work for a shop in NY we got asked to help ICOM program a ton of radios that were going North of the boarder. They sent us a codeplug and just told us to program and box. I think most were going to a logging company. I wish I had saved the code plug.  



#5 Lscott

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Posted 01 February 2021 - 09:18 AM

There are other interesting oddball radio services out there that people are not aware of. For example there are license free 900MHz radios. Some of those radios are not cheap either. Might be fun to play with a few but not at $300+ per unit.

 

https://www.amazon.c...l/dp/B07PM684WN

 

https://www.motorola...#tabproductinfo


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#6 tweiss3

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Posted 01 February 2021 - 02:07 PM

There are other interesting oddball radio services out there that people are not aware of. For example there are license free 900MHz radios. Some of those radios are not cheap either. Might be fun to play with a few but not at $300+ per unit.

https://www.amazon.c...l/dp/B07PM684WN

https://www.motorola...#tabproductinfo


The Moto DTR radios work pretty well and are license free. Great site radios, they use frequency hopping to stay private and interference free I. The 900MHz band.
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#7 Lscott

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Posted 02 February 2021 - 08:30 AM

The Moto DTR radios work pretty well and are license free. Great site radios, they use frequency hopping to stay private and interference free I. The 900MHz band.

I would assume they are not compatible with other manufacture's FHSS radios. If that's the case then one is locked into only buying Moto equipment. Not a good situation.



#8 n1das

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Posted 03 February 2021 - 09:31 PM

The Moto DTR radios work pretty well and are license free. Great site radios, they use frequency hopping to stay private and interference free I. The 900MHz band.

 

I am a user of the DTRs and the DLRs and a serious fan of them.    I own a small fleet of legacy DTR650 radios and a small fleet of DTR700 radios.  The DTR650 has been around since 2006 and was discontinued in November 2018 when the DTR600/700 models were released.  The DTR600 and DTR700 models are the replacement for the legacy DTR 410/550/650 models.  The DTR600/700 programs a little differently from the legacy DTRs but are fully backward compatible.  I have also owned a small fleet of DLR1060 radios which also work with the DTRs.  I later sold my DLRs to a friend for his business.  At first he wasn't sure what he was going to use them for except maybe as rental radios for his customers but now he and his employees use them all the time around the office and at jobsites.

 

The DTRs are my professional quality digital replacement for GMRS/FRS for local on-site simplex type use with family and friends.  I never got them to set any range records but they work amazingly well and are capable of outperforming conventional Part 90/95 UHF portables on simplex.  Where they beat other radios is when working inside buildings.  Where they blow all others away is when aboard cruise ships.  People who have used them on 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.  The many reflections inside the cruise ship actually helps and the FHSS operation effectively stirs the modes as the frequency hops.

 

The DTRs and DLRs use a hopset of 50 frequencies spread across the entire 902-928MHz band and spend no more than 90ms on any given freq in the hopset.  The DTRs make about 11 hops per second.  The digital modulation on a given freq in the hopset is according to an 8-level modulation scheme.  The occupied BW on a given freq in the hopset is around 26 kHz.  Motorola's VSELP vocoder is used.

 

Per FCC 15.247, an FHSS device operating in the 902-928MHz band must use a minimum of 50 frequencies in the hopset and output power is limited to 1W (+30dBm).  The legacy DTRs were FCC certified at 890mW (+29.5dBm).  The DTR600/700 models were FCC certified at 830 mW (+29.2 dBm).  The DLRs were FCC certified at 880mW (+29.4 dBm).  The few tenths of a dB under the +30dBm legal limit is to account for measurement uncertainty and slight variation in power output from unit to unit and not exceed the 1W (+30dBm) legal limit.  The power numbers in the FCC certs reflect what was measured from the individual sample submitted to the accredited test lab for cert testing.

 

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 (KAE9013) since 1992 and using good quality commercial gear.  I want an all digital solution that is higher quality and more professional than FRS.  The fact that they are completely scanner proof and can be made very secure via private talkgroups and private 1 to 1 calling comes as a bonus.  I still have GMRS/FRS and MURS but they are no longer my default go-to mode local on-site simplex use with family and friends.  Aside from occasional light use of FRS with my young nephews when they come to visit, I hardly use GMRS/FRS at all anymore.

 

I have a small fleet of DTRs because they won't work with any non-Moto FHSS radios.  I have them ready to hand out to friends and family members.  I'm OK with them not working with non-Moto FHSS radios because I didn't get them to work with any other radios.  No other manufacturer currently has a 900MHz FHSS radio that can hold a candle to the Motorola DTRs and DLRs.  Retevis has dangled a 900MHz license-free model but it appears to be vaporware from what I can tell.


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David Sterrett, N1DAS

Nashua, NH, USA

Ham [HA] = N1DAS (2/1984)

GMRS [ZA] = KAE9013 (12/1992)

 


#9 Lscott

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Posted 03 February 2021 - 10:45 PM

That was a very nice write on those radios. Your comments about how they out perform typical FRS/GMRS radios in tight quarters is worth noting. That could help somebody who needs a better solution. The experience on a cruise ship with FRS radios is something I’ve read from time to time as being poor, so these radios would be the solution, but not cheap. For me the main point was at the very end, the part where the radios will not interoperate with non-Moto models. That ends any idea I had of scouting out one to experiment with, not to mention the cost.
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#10 n1das

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Posted 03 February 2021 - 11:07 PM

That was a very nice write on those radios. Your comments about how they out perform typical FRS/GMRS radios in tight quarters is worth noting. That could help somebody who needs a better solution. The experience on a cruise ship with FRS radios is something I’ve read from time to time as being poor, so these radios would be the solution, but not cheap. For me the main point was at the very end, the part where the radios will not interoperate with non-Moto models. That ends any idea I had of scouting out one to experiment with, not to mention the cost.

 

Yeah the DTRs are not cheap.  The DLRs are a little cheaper but not by much.

 

Motorola has no plans to obsolete them anytime soon, part of why I'm not worried about them not working with non-Moto radios.  The DTRs have developed a cult-like following over the years.  Count me in! LOL.  Use in hotels and schools are where they are popular.  Some healthcare facilities are using them.  Check out the Rutland VT case study.  The Rutland Hospital case study is a bit dated as DTR550s were used.  The DTR600/700 models are the replacement models.

https://www.motorola..._case_study.pdf

 

The DLRs were developed for retail business users as a digital upgrade or replacement for the very popular CLS series UHF business radios.  The DTRs are loaded with features but often represent too much radio for the average business radio user in a retail environment.  The DLRs are Motorola's answer to that.  DLR = Digital Lightweight Radio, according to Motorola.  The DLRs are smaller than most FRS bubble packs and makes them great "stealth" radios.  The DLR's RF performance is identical to the DTRs. The DLRs make sense for the target market. The local Costco Wholesale near me is using DLR radios and I can hear them on the factory default public talkgroups when I'm in range.

https://www.motorola...ital-radio.html

 

The DTRs and DLRs all work with each other right out of the box at the factory default settings.  No programming is needed to get them talking to each other.  Customization of features and settings requires the Motorola Business Radio CPS, a free download from Motorola.  The CPS cable is about $35 on Amazon.  Many people appear to be using them right out of the box at the factory default settings like FRS bubble packs.  I have programmed mine to set up private talkgroups to secure my fleet.  I also kept the default public groups in the programming so they can still work with DTRs and DLRs at the factory default settings.


David Sterrett, N1DAS

Nashua, NH, USA

Ham [HA] = N1DAS (2/1984)

GMRS [ZA] = KAE9013 (12/1992)

 


#11 Lscott

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Posted 04 February 2021 - 12:11 AM

I just checked eBay for the DLR1060 6 channel model. Most were very expensive but two were reasonably priced, $50 and $70. I looked quickly at the Moto site for info. You’re right the DLR series is about as basic as you can get.
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#12 n1das

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Posted 04 February 2021 - 01:55 AM

You can find the legacy DTRs very cheap on eBay but their condition is a big "?".  The DLRs and DTR600/700 are still expensive on the used market.

 

The DLRs are packed with the features of the DTRs, minus a display and some channel capacity and larger removable antenna.  Don't be fooled by what appears to be very basic radio.  It is packed with hidden features that work with the DTR's features.  It is set up to be as basic as you can get like you said.  Some people have commented that they don't like the large round PTT button on the front of the radio because they are so accustomed to a PTT button on the side of a radio.  I found the large PTT button on the radio makes perfect sense because the radio is so small.  A thumb press using either hand is all it takes and the radio is comfortable to hold.  The PTT button of the front is different from what people are used to but it makes perfect sense for such a small radio.  Battery life on a charge is in excess of 15 hours (5/5/90 duty cycle), similar to the DTR600/700 models.

 

Another option is a pair of old NEXTEL Motorola i355 handsets. These iDEN handsets and a few other models have an off-network phone to phone feature which NEXTEL called Direct Talk.  This is different from the NEXTEL DirectConnect PTT feature which used NEXTEL's iDEN network.  The Direct Talk (DT) feature allows 2 or more phones to communicate simplex on 900MHz when in range of each other.  It was useful for contractors at jobsites where one or more of their NEXTEL phones had no network service, which was common when working in a basement of a building.  The DT feature offered a solution to this problem when phones had no service but were in simplex range of each other.  The DTRs and DLRs are a spinoff from this feature.  The DTRs and DLRs use the exact same FHSS system but differ in software only. The DTRs and DLRs are incompatible with the off-network DT feature and supposedly was done on purpose.  The legacy DTRs and one particular iDEN handset (i325 or i325is, IIRC) were originally one and the same at the start of their design but at some point they split away and became separate products but still shared a common design.  I suspect the software incompatibility came when more DTR-specific features were added to the DTRs.  The Direct Talk (DT) user interface is a primitive version of the DTRs.  MOTOTALK was the original silly Motorola name for this system.

https://en.wikipedia.../wiki/MOTO_Talk

 

You can find i355 and other Direct Talk capable iDEN phones dirt cheap on eBay.  I recently re-batteried my DTR650 fleet so I know replacement batteries are readily available for them.  The one gotcha with these is they need to have a SIM card which has previously been activated on an iDEN network (NEXTEL) in order to enable the DT feature.  The DTRs and DLRs have an 11 digit private ID in each radio that was assigned at the factory by Motorola and is not changeable by the end user or with the CPS.  The ID functions as a hardware electronic serial number (ESN).  The DTRs and DLRs use an ID-based system for private groups and 1 to 1 private calling.  The radios only know each other by their 11 digit private ID.  The DT features in the iDEN phones create this ID from 1 plus the area code and phone number in the SIM card that was assigned by the iDEN carrier (NEXTEL).  If used phones have a SIM in them that was previously activated by an iDEN carrier then you are good to go.  There are plenty of YouTube videos describing and demoing the Direct Talk feature.

 

My wife (g/f at the time) and I had a pair of i355 phones back in the day and we played with the DT feature and that's when I first learned of the DTRs.


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David Sterrett, N1DAS

Nashua, NH, USA

Ham [HA] = N1DAS (2/1984)

GMRS [ZA] = KAE9013 (12/1992)

 


#13 Lscott

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Posted 04 February 2021 - 07:00 AM

Thanks for the history lesson. Learned a bit more about where some of the radio technology came from and why. Just proves there is always something more to learn out there.

#14 gman1971

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Posted 04 February 2021 - 05:12 PM

I think the DTR is a much better alternative for site radios than the FRS garbage. Yes, its more expensive, but they are quite hard to scan, and offer pretty decent privacy, maybe not as secure as AES but, they will be far better than anything CCR FRS...

 

The display is the same used in the XPR7550 radios, which is nice.

 

 

G.



#15 Lscott

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Posted 04 February 2021 - 09:34 PM

I use my CCR at work as a cheap scanner. In the industrial park some businesses cheap out using FRS radios for their shop maintenance staff. A few things I heard would have been better said in private. Spending few extra bucks on the radios with some measure of builtin security would keep busybodies like me hearing what is going on. I guess people get a radio, and never gave it much thought, where one mouth is doing the talking and 100 ears all over the area are hearing every thing said.



#16 gman1971

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Posted 04 February 2021 - 10:31 PM

Yep, for LMR we use only the three letter acronym security, but even Basic Privacy on most Motorola XPR radios will thwart all CCRs and scanners.

 

DTR radios will also stop guys like Lscott in their tracks... LOLOL :)

 

G.






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