coryb27

Funny no matter what Forum linking comes up in it always starts a POTS debate, one that's been beat to death. Nothing I do is over POTS, in fact the Asterisk server is sitting on optical fiber and the nodes on dedicated point to point connections or cable. As an IT professional of 25 years I can assure you DSL is not POTS. Unless you are doing an auto patch to a POTS line or using dial up for your internet chances are your internet has been been off the last mile for years.

What does “duty cycle” mean?
 
I bring up duty cycle every time I hear somebody talking about making a repeater out of cheap Chinese mobiles and worse any type of handhelds. Duty cycle is the maximum time an amplifier may transmit within a five minute interval, expressed as a percentage, to avoid overheating. Suppose a mobile amplifier is rated at 30% duty cycle. This means that it may transmit for no longer than 1.5 minutes and must remain off for not less than 3.5 minutes. Some people forget that a repeater is transmitting for 2 or more people, duty cycle will be reached quickly if you get into conversation. More people in the conversation just amplifies the issue.
 
Once a radio reaches it's thermal design limits it will no longer be able to adequately cool the output transistors. Even if a radio is not hot to the touch the transistors are, in part because of the inefficient transfer of heat to the units housing or internal heat sink. The longer you exceed the duty cycle the more heat builds on the transistors, surrounding electronics and heat sink effecting it's ability to remain on frequency without spurious emissions. Exceed duty cycle long enough and you will need a new transmitter or radio.
 
I have tested a few Baofang and TYT radios on my service monitor without great results. All of the radios started deviating outside of the allotted channel bandwidth after simulated conversation at 50% duty cycle, the longer I allowed this the worse if got. Testing was done using an Aeroflex 2975 IFR recently back from the calibration lab. 
 
GMRS is a tiny sliver of spectrum surrounded by the commercial land mobile part 90 service. It is important that any repeaters that are built or re-purposed are held to the highest standards and operated as to not cause any interference inside or outside of our allocated spectrum. I wont get into the part 90/95 debate but i do stand firm that non certified import equipment has no place on GMRS. 

We are using Asterisk as the server (running on a raspberry pi 3) and the RTCM made by micro-node. Cheaper hardware solutions vs the RTCM are available but require other configuration. I have not used any of the other hardware so I wont touch on that. I chose the RTCM for its single unit design and application specific properties. The interfacing with the RTCM is rather simple, I went with the MTR2000 repeater for reliability, full duty cycle and used market availability. 
 
Our group hosts its own local node server (Asterisk running on a raspberry pi 3) with 6 repeaters connected to it. This local node also allows us access to the MyGMRS national linking network hosted by the owner of this site. By entering commands in Asterisk or using DTMF,  links to other systems can be connected or disconnected on the fly. Things like usage counters and the visual map show links with red lines as well as what site is transmitting by changing its marker from green to red, all of this in real time.
 
Its not as hard as it sounds, Rich from MyGMRS was a huge help, you can also find a linking thread in the private section here. Along the way I found a company that was able to build a custom cable for interfacing the MTR2000 with the RTCM, it provides a reliable solution that's repeatable and works flawless. The MTR2000 repeater can be configured to work with the RTCM rather simply using the repeaters wire-line card to handle the audio and the 96 pin J5 connector to pull ctcss, core, ptt and power.
 
We are using the RTCM and MTR at 6 sites with a stand alone MTR at a 7th and could not be happier. These machines are worth every penny, its not 2 mobiles in a box its a true full duty cycle, commercial grade repeater. Due to the simplicity I have several more RTCM / MRT2000 combos ready to go I just need to fined a few more tower sites with internet.
 
Hope this answers a few questions.

We are already doing it http://link.mygmrs.com
 
Corey

We are using Asterisk as the server (running on a raspberry pi 3) and the RTCM made by micro-node. Cheaper hardware solutions vs the RTCM are available but require other configuration. I have not used any of the other hardware so I wont touch on that. I chose the RTCM for its single unit design and application specific properties. The interfacing with the RTCM is rather simple, I went with the MTR2000 repeater for reliability, full duty cycle and used market availability. 
 
Our group hosts its own local node server (Asterisk running on a raspberry pi 3) with 6 repeaters connected to it. This local node also allows us access to the MyGMRS national linking network hosted by the owner of this site. By entering commands in Asterisk or using DTMF,  links to other systems can be connected or disconnected on the fly. Things like usage counters and the visual map show links with red lines as well as what site is transmitting by changing its marker from green to red, all of this in real time.
 
Its not as hard as it sounds, Rich from MyGMRS was a huge help, you can also find a linking thread in the private section here. Along the way I found a company that was able to build a custom cable for interfacing the MTR2000 with the RTCM, it provides a reliable solution that's repeatable and works flawless. The MTR2000 repeater can be configured to work with the RTCM rather simply using the repeaters wire-line card to handle the audio and the 96 pin J5 connector to pull ctcss, core, ptt and power.
 
We are using the RTCM and MTR at 6 sites with a stand alone MTR at a 7th and could not be happier. These machines are worth every penny, its not 2 mobiles in a box its a true full duty cycle, commercial grade repeater. Due to the simplicity I have several more RTCM / MRT2000 combos ready to go I just need to fined a few more tower sites with internet.
 
Hope this answers a few questions.

That's not a mobile repeater in that pic, its a HAM operating HF. As far as a mobile repeater it really is a waste of time. I have done this already and it was a total disappointment.. Unless your car is at a substantial height advantage you will not have any better coverage then simplex. Again you can and will try to explain or reason away my logic without listening to what I and others have been trying to tell you. I have tried the mobile repeater, the setup was a 50W Motorola SLR 5700 with a 4 cavity BP/BR duplexer connected to a 5.5dB gain antenna on the top of my truck. After testing for about month I realized it had no practical use and only offered slightly more range than simplex, best part I ended up needing a jump after a day at the fair. Mind you this was a $2400 repeater, $800 duplexer with an antenna that was tuned using an Anritsu S331D. I promise I nor anybody on this site will try to steer you wrong, I hold a Commercial, Amateur and GMRS license, own and operate several large repeaters and have all the gear for building, testing and maintaining these kinds of systems.

Motorola, Icom, Kenwood all make new radios that can be set to wideband. Motorola uses Entitlement keys, Icom can be set in the options, Kenwood I think requires a key.

That's not a mobile repeater in that pic, its a HAM operating HF. As far as a mobile repeater it really is a waste of time. I have done this already and it was a total disappointment.. Unless your car is at a substantial height advantage you will not have any better coverage then simplex. Again you can and will try to explain or reason away my logic without listening to what I and others have been trying to tell you. I have tried the mobile repeater, the setup was a 50W Motorola SLR 5700 with a 4 cavity BP/BR duplexer connected to a 5.5dB gain antenna on the top of my truck. After testing for about month I realized it had no practical use and only offered slightly more range than simplex, best part I ended up needing a jump after a day at the fair. Mind you this was a $2400 repeater, $800 duplexer with an antenna that was tuned using an Anritsu S331D. I promise I nor anybody on this site will try to steer you wrong, I hold a Commercial, Amateur and GMRS license, own and operate several large repeaters and have all the gear for building, testing and maintaining these kinds of systems.

Corey
 
 Great information. 

That's not a mobile repeater in that pic, its a HAM operating HF. As far as a mobile repeater it really is a waste of time. I have done this already and it was a total disappointment.. Unless your car is at a substantial height advantage you will not have any better coverage then simplex. Again you can and will try to explain or reason away my logic without listening to what I and others have been trying to tell you. I have tried the mobile repeater, the setup was a 50W Motorola SLR 5700 with a 4 cavity BP/BR duplexer connected to a 5.5dB gain antenna on the top of my truck. After testing for about month I realized it had no practical use and only offered slightly more range than simplex, best part I ended up needing a jump after a day at the fair. Mind you this was a $2400 repeater, $800 duplexer with an antenna that was tuned using an Anritsu S331D. I promise I nor anybody on this site will try to steer you wrong, I hold a Commercial, Amateur and GMRS license, own and operate several large repeaters and have all the gear for building, testing and maintaining these kinds of systems.

That's not a mobile repeater in that pic, its a HAM operating HF. As far as a mobile repeater it really is a waste of time. I have done this already and it was a total disappointment.. Unless your car is at a substantial height advantage you will not have any better coverage then simplex. Again you can and will try to explain or reason away my logic without listening to what I and others have been trying to tell you. I have tried the mobile repeater, the setup was a 50W Motorola SLR 5700 with a 4 cavity BP/BR duplexer connected to a 5.5dB gain antenna on the top of my truck. After testing for about month I realized it had no practical use and only offered slightly more range than simplex, best part I ended up needing a jump after a day at the fair. Mind you this was a $2400 repeater, $800 duplexer with an antenna that was tuned using an Anritsu S331D. I promise I nor anybody on this site will try to steer you wrong, I hold a Commercial, Amateur and GMRS license, own and operate several large repeaters and have all the gear for building, testing and maintaining these kinds of systems.

Motorola gear is a pain to get programming software for but not impossible. I can take a week or longer to navigate Motorola's process but in the end you will have legal software and you can get the entitlement for wideband operation for free after some quick online training. I use Motorola for the options alone, in the truck I run handheld control heads and a long range Bluetooth speaker mic so I can use the trucks radio well in restaurants our friends houses. The same mic is also on my base paired with a desktop mic, its nice being able to go anywhere in the house and just carry a small mic that allows the use of the base. This gear is a little pricey but can be found used on ebay reasonable, its all comes down to personal preference.
 
Bluetooth Mic that can be attached to most of the newer Motorola XPR radios including portables.
 
http://mwgmrs.com/mygmrs/handmic.jpg
 
This is the handheld control head, it is also the speaker and mic, 4 years old an not a single issue.
 
http://mwgmrs.com/mygmrs/truck1.jpg
 
Radio Head unit is installed under the back seat.
 
http://mwgmrs.com/mygmrs/truck2.jpg
 
The control head cable comes thru the map pocket allowing it to tuck away nicely out of sight.
 
http://mwgmrs.com/mygmrs/truck4.jpg
 
Simple 1/4 wave gives great performance, i am able to hit repeaters 30 miles away and simplex 10 miles easy in the freeway.
 
http://mwgmrs.com/mygmrs/truck3.jpg

Don't get discourage by the lack of users in your area rather embrace the lack of and if no repeater is available in your area install one. I have learned if you build it they will come. Start a club or group, put up a web page, start a Facebook group for your area etc.. You will be surprised how quickly like minded people  will get licensed to talk with others that share the same interests.

Don't get discourage by the lack of users in your area rather embrace the lack of and if no repeater is available in your area install one. I have learned if you build it they will come. Start a club or group, put up a web page, start a Facebook group for your area etc.. You will be surprised how quickly like minded people  will get licensed to talk with others that share the same interests.

Thats nice but pricey lol. Also I don't have a MOL account (I cant even figure out how to get one) making it difficult to get software, but it is nice to hear Motorola finally moved forward with their software accessibility lol. I still remember the DOS window and the big black box that needed its own power supply.

Motorola gear is a pain to get programming software for but not impossible. I can take a week or longer to navigate Motorola's process but in the end you will have legal software and you can get the entitlement for wideband operation for free after some quick online training. I use Motorola for the options alone, in the truck I run handheld control heads and a long range Bluetooth speaker mic so I can use the trucks radio well in restaurants our friends houses. The same mic is also on my base paired with a desktop mic, its nice being able to go anywhere in the house and just carry a small mic that allows the use of the base. This gear is a little pricey but can be found used on ebay reasonable, its all comes down to personal preference.
 
Bluetooth Mic that can be attached to most of the newer Motorola XPR radios including portables.
 
http://mwgmrs.com/mygmrs/handmic.jpg
 
This is the handheld control head, it is also the speaker and mic, 4 years old an not a single issue.
 
http://mwgmrs.com/mygmrs/truck1.jpg
 
Radio Head unit is installed under the back seat.
 
http://mwgmrs.com/mygmrs/truck2.jpg
 
The control head cable comes thru the map pocket allowing it to tuck away nicely out of sight.
 
http://mwgmrs.com/mygmrs/truck4.jpg
 
Simple 1/4 wave gives great performance, i am able to hit repeaters 30 miles away and simplex 10 miles easy in the freeway.
 
http://mwgmrs.com/mygmrs/truck3.jpg

I got all my guys.(all of two of them) there GRMS license. 

If you program a Baofeng UV-5R to GMRS you need a GMRS licence. I see you understand that the radio is indeed a HAM radio and by the part 95 rules that your GMRS licence is authorized forbids the use of such equipment on GMRS. I won't get into all the details but here is the simple and best way I know how to explain this. Since no test or radio knowledge is required to get a GMRS licence its operating rules require certified transmitters to maintain the integrity of the service. GMRS is located within a tiny sliver of the part 90 commercial radio service used by business, ambulance services, fire depts, and well you get the picture. By using non certified low quality transmitters you risk causing harmful interference to other licensed services, if caught you will be held accountable. I am not here to tell you what you can and can't do but I hope you take something away from my ramblings because in the end the choice is yours. 

Motorola gear is a pain to get programming software for but not impossible. I can take a week or longer to navigate Motorola's process but in the end you will have legal software and you can get the entitlement for wideband operation for free after some quick online training. I use Motorola for the options alone, in the truck I run handheld control heads and a long range Bluetooth speaker mic so I can use the trucks radio well in restaurants our friends houses. The same mic is also on my base paired with a desktop mic, its nice being able to go anywhere in the house and just carry a small mic that allows the use of the base. This gear is a little pricey but can be found used on ebay reasonable, its all comes down to personal preference.
 
Bluetooth Mic that can be attached to most of the newer Motorola XPR radios including portables.
 
http://mwgmrs.com/mygmrs/handmic.jpg
 
This is the handheld control head, it is also the speaker and mic, 4 years old an not a single issue.
 
http://mwgmrs.com/mygmrs/truck1.jpg
 
Radio Head unit is installed under the back seat.
 
http://mwgmrs.com/mygmrs/truck2.jpg
 
The control head cable comes thru the map pocket allowing it to tuck away nicely out of sight.
 
http://mwgmrs.com/mygmrs/truck4.jpg
 
Simple 1/4 wave gives great performance, i am able to hit repeaters 30 miles away and simplex 10 miles easy in the freeway.
 
http://mwgmrs.com/mygmrs/truck3.jpg

Not true, GMRS can be used for business purposes as long as each individual person is licensed. No licenses will be issued to a business entity, only individuals. So if you have 5 people that need to communicate for the business, you better have 5 licenses (assuming none of them are related, otherwise the relatives can share the one license).

GMRS can not be used for business, not even as a backup to AT&T. The FCC will be happy to licences you for your business under the part 90 industrial pool, GMRS is for personal and family use.

I will leave this right here
 
http://mwgmrs.com/mygmrs/chart.jpg

That's a heck of a lot easier to read than what I wrote!  LOL

I will leave this right here
 
http://mwgmrs.com/mygmrs/chart.jpg

Perhaps I was being too subtle. Let me be a little more direct. It seems to me you spend a lot of time asking others for support in your quest for solutions for problems that do not exist. As to the specific suggestion about a Dual-Mode repeater, exactly what problem are you trying to address?  
 
If you are just dreaming of what could be, then as I have tried to tell you at least twice previously, there is already an excellent service for that, amateur radio. Instead of floating ideas you want other's opinions on, take the time to get a study book and take the ham radio technician test. Honestly, it is easy. If you can't grasp the (fairly basic) technological side at first, just study the questions and memorize the answers - believe me, you would not be the first person do do that.  The test consists of 35 questions drawn from a pool of 426 questions... and all 426 of them are available online or in print.  With a ham ticket (and a little money)  in hand, you would be free to start experimenting with some of your ideas.