MTR3000 Repeater

[zerodayjames]

Hi all this is my first post on here. Went awhile without finally hopping on a forum. I got my General in October but still learning A LOT.

So I built a repeater with two Wouxon KG-UV980Ps and it turns out when they are in repeater mode they are absolutely terrible. Plan is to upgrade to a dedicated Motorola repeater.

Originally I was looking at the MTR2000. I found a decent one on Haloid Radios for $799.99 which is within the budget. I am now looking at the MTR3000 as it is MOTOTRBO capable and I want to look into the ability to pass AES 256 encryption. The price is far greater but this model gives me room to learn more about DMR and grow my knowledge.

My question is sort of multi parted. I want to start with a repeater that is somewhat affordable to get started (originally budget was 2k but here we are...) I also want something that has room for growth and learning. DMR encryption is high on that priority list to get familiar with. I found a package on eBay for an MTR3000 with a Sinclair Q301GC-2 duplexer for $3500. This would be perfect I feel for my application. My concern is the ability to support this unit considering its end of life. Would it be a better move to go for the SLR8000 (FAR out of my budget) or is there enough resources for programming/learning still out there for the MTR3000?

Any knowledge and wisdom is appreciated.

 

[mmckenna]

If you are in the USA, and you plan on using this on amateur radio frequencies, encryption is strictly forbidden by FCC amateur radio rules.

If you need analog only, you can get used repeaters much cheaper, $800 for an MTR2000 is way high. You can get P25 equipped Quantars for half that price.
If you need DMR, there are other options. $3500 is also pretty high in my book.

There's a lot of support for both the MTR-2000 and MTR-3000. The Motorola MTR2000 Information Index Page

 

[zerodayjames]

If you are in the USA, and you plan on using this on amateur radio frequencies, encryption is strictly forbidden by FCC amateur radio rules.

If you need analog only, you can get used repeaters much cheaper, $800 for an MTR2000 is way high. You can get P25 equipped Quantars for half that price.
If you need DMR, there are other options. $3500 is also pretty high in my book.

There's a lot of support for both the MTR-2000 and MTR-3000. The Motorola MTR2000 Information Index Page

Thanks @mmckenna. Yes, I am in the USA and saw that encryption on HAM frequencies is prohibited. Just wanted to be able to have the option to learn the technology and have the capability in case of an apocalypse.

I would like to have the option for both analog and digital. Are the P25 equipped Quantars capable of both? Or just digital?

Yeah $3500 for an MTR3000 is definitely high. It does come with a bangin duplexer though which I will need. I saw other cheap Chinese 100W duplexers on eBay for $150. Just wasn't sure about the quality of those.

 

[Project25_MASTR]

MTR2000's should run between $200 and $400. I wouldn't pay more than $800 for a MTR3000 and would only pay MTR2000 prices for a MTR2000 chassis with a MTR3000 exciter, receiver and SCM installed. The MTR's had well known power supply issues that caused fairly regular failure especially in situations where you have dirty power.

When they work, they work extremely well. I still have a few MTR2000's laying around but the RSS won't run on modern 64 bit computers so you have to keep a bit of an older machine around to work on them. Quantar RSS does support 64 bit operating systems but just keep in mind, MTR3000's are DMR capable, Quantar's are P25 capable. Both are digital...but not the same digital.

 

[mmckenna]

in case of an apocalypse.

I would like to have the option for both analog and digital. Are the P25 equipped Quantars capable of both? Or just digital?

They'll do analog. They'll do P25. They'll do mixed mode.

Yeah $3500 for an MTR3000 is definitely high. It does come with a bangin duplexer though which I will need. I saw other cheap Chinese 100W duplexers on eBay for $150. Just wasn't sure about the quality of those.

If you want a good repeater, get a good duplexer. Still not sure it's a good deal for $3500.

 

[kayn1n32008]

Thanks @mmckenna. Yes, I am in the USA and saw that encryption on HAM frequencies is prohibited. Just wanted to be able to have the option to learn the technology and have the capability in case of an apocalypse.

I would like to have the option for both analog and digital. Are the P25 equipped Quantars capable of both? Or just digital?

Yeah $3500 for an MTR3000 is definitely high. It does come with a bangin duplexer though which I will need. I saw other cheap Chinese 100W duplexers on eBay for $150. Just wasn't sure about the quality of those.

Look for XPR8400/8300 repeaters. Should be finding them for a lot less. Yes they are 2 mobiles in a box, but if you're not keying down for hours, and they are adequately cooled, they will work just fine, and be a lot friendlier on your budget.

DO NOT cheap out on the duplexer. You really should be using a 4-6 cavity Band Pass/Band Reject(BpBr) duplexer. Lots of options. Sinclair, TxRx Systems, Comprod are good options.

I won't debate encryption legalities, but the XPR8300/8400/MTR3000/SLR are all capable of encrypted operation. Both EDP and AES with the appropriate option selected in CPS.

P25 is an option. Motorola, Tait, and Codan are excellent manufacturers. My preference for repeaters is Codan MT-4. They pop up on ebay fairly regularly. Not a beginner repeater though.

Motorola Quantar are fairly bullet proof, but incredibly heavy and very power hungry.

With P25 and encryption, MOST radios require a key loader to load encryption keys where as with most DMR radios, keys are loaded via CPS.

 

[zerodayjames]

@Project25_MASTR
Thanks for the clarification between the repeaters on P25 and DMR. I am still unfamiliar with both digital platforms so I really wouldn't know which would be better to go with. From what I've read it looks like AES 256 bit encryption is the highest available currently so I would want to go with that. I'm a security guy so the more bits the better. More importantly, where in the world are you finding MTR2000s and 3000s for that price!!! I've been looking everywhere and the cheapest MTR2000s are going for $650. Cheapest MTR3000s are $1800 at least.
@mmckenna
Definitely don't want to cheap out on the duplexer. That's kind of why I was feeling this package deal with the Sinclair 6 cavity. But if ya'll are saying I can find better deals then I trust it.

@kayn1n32008
I was looking at XPR8400s as well but I'm leaning more towards the 100W capability.

So this is the link to the one I am looking at. I was able to talk the seller down a bit but I'm just in love with that beefy duplexer it comes with.

Motorola MTR3000 UHF 403-470Mhz 100W Digital Repeater CAP PLUS MULTI/CAP SINGLE | eBay

Motorola MTR3000 UHF Repeater w/ CONNECT PLUS, model number T3000A. This is a 100 watt repeater with a band split of 403-470 Mhz. These units are capable of both wide band and narrow band operation.

www.ebay.com

The Quantar seems like an option. I like the 110W capability for sure as well as P25. But power hungry would be an issue as my backup battery is 1200kwh. Not the biggest. I do love how it looks like a straight tank though.

Can you explain to me the need for a key loader when using P25 encryption vs CPS on DMR? Is the key loader a separate software/device? And CPS? Is this an easier method? I'm coming from a background of licensed electrician to cyber security tech so I would consider myself fairly tech savvy. Still would like to go for a beginner level entry though.

 

[kayn1n32008]

@kayn1n32008
I was looking at XPR8400s as well but I'm leaning more towards the 100W capability.

Unless you're going to be combining the repeater with 1 or more other repeaters, using the same antenna, you won't see much difference between 45w and 100w.

 

[kayn1n32008]

The Quantar seems like an option. I like the 110W capability for sure as well as P25. But power hungry would be an issue as my backup battery is 1200kwh. Not the biggest. I do love how it looks like a straight tank though.

Can you explain to me the need for a key loader when using P25 encryption vs CPS on DMR? Is the key loader a separate software/device? And CPS? Is this an easier method? I'm coming from a background of licensed electrician to cyber security tech so I would consider myself fairly tech savvy. Still would like to go for a beginner level entry ththough.

Again, dont get hung up on 100w. You're not going to gain much unless you are dealing with combiner losses when combining multiple repeaters to a single antenna.

Encryption capabilities were in the fore thought of the P25 spec, as is security of the key.

Encryption on DMR was an afterthought. Only Kenwood(and possibly Tait) need key loaders to load AES/DES/ARC4(EDP/ADP) keys.

 

[MTS2000des]

The biggest factor in a well performing repeater system is the duplex filter/band pass filter, feedline and antenna choices- and of course, the site itself.

Blowing a wad on a high tier repeater is pointless if one has a poor antenna/feedline/duplexer and related hardware and a poor site.

 

[W9WSS]

Have you checked with your state or regionwide repeater coordination council? You just can't put an Amateur Radio repeater on the air unless you are coordinated. I would check with them, and see if there are any UHF or VHF repeater pairs available. Putting something haphazardly on the air could result in being ordered off that frequency, especially if you haven't done your research.

 

[mmckenna]

Again, dont get hung up on 100w. You're not going to gain much unless you are dealing with combiner losses when combining multiple repeaters to a single antenna.

This is worth repeating.

As a new ham, please take this as some kind recommendations from guys that have been hams for a very long time, as well as work in the public safety radio industry:

New hams/hobbyists put WAY too much emphasis on power output. Don't sink your budget on trying to get 100 watts, then skimp on the duplexer/filters/coax/antenna system. You'll get way more benefit out of better antenna system/duplexers than you'll ever see by jumping from 50 watts to 100 watts.

You need to remember it is TWO WAY radio, as in it transmits AND it receives. Putting in a 100 watt repeater that can't hear a radio trying to talk back into the system from 3 miles away is wasted cash. Search these forums, there's a lot of posts where people have done this exact thing, and end up spending big bucks on replacing cheap duplexers/feed line/antennas.

 

[kayn1n32008]

Have you checked with your state or regionwide repeater coordination council? You just can't put an Amateur Radio repeater on the air unless you are coordinated. I would check with them, and see if there are any UHF or VHF repeater pairs available. Putting something haphazardly on the air could result in being ordered off that frequency, especially if you haven't done your research.

If coordinating where the OP is, is anything like where I live, it's going to be a ton of paper repeaters and 'nothing available'. Pick a pair, listen for a month and if you hear nothing put up your machine. All coordinating does is offer limited protection if a Rouge machine goes up. Worst case there are usually 'shared, non-protecred' pairs intended for short term or portable repeaters.

If it's a paper repeater, be prepared for some old **** whining that your using 'his' pair

 

[W9WSS]

Fortunately, that's NOT the way it works in Illinois and the nine surrounding states.

www.ilra.net

 

[zerodayjames]

Wanted to just update my original post but not sure if that's an option so I'll post it here.

Current setup: (Keep in mind I am changing this up quite a bit)

I have two Wouxon KG-UV980P mobile radios setup in repeat mode.

North TX Tower: Mast is a 20 ft. pole on the roof which stands a total height of 30 ft. plus the height of the antenna which is another 8 ft.
Antenna is a "dual band" Tram 1480. I put "dual band" in quotes as I swept the UHF and VHF bands to find the best SWR of 1.2:1 at 420 MHz and 1.2:1 at 145.500 MHz. The rest are off the charts. I am using a total of 35 ft. of M&P Extra Flex Bury 13 Premium .500 coax cable with a lightning arrestor/ground placed right when the coax enters the home.

South RX Tower: Mast is a 10ft pole on the roof which stands a total height of 20 ft. plus the height of the antenna which is another 8 ft. Same antenna as TX. Same coax as TX with a total run of 20 ft. from the antenna to the radio.

The two antennas/radios are placed on opposite sides of the house connected with a length of Ethernet cable.

Antennas have 40 ft. of horizontal separation and 10 ft. of vertical separation. (This does not include the height of the antennas which take away from the vertical spacing.)

I will be scrapping the use of two antennas and opt for a duplexer on the taller tower. I also plan to extend this tower another 10 ft. to bring it to a total height of 40 ft. not including the height of the antenna. When I do this I also plan to replace the Tram with a Hustler G6-440.

I decided to use the UHF band as I got better results when running simplex tests in my area, which is very urban, slightly hilly and decent amount of homes/buildings.

The location is not "ideal" as I am not high up on a hill, but it is at least a higher elevation than some of the areas I would like to reach. I also considered renting space on a site. This would solve all my issues as there are repeaters on there currently that I am able to hit and get to where I want. But I haven't looked into all the costs and honestly would prefer to self host.

Thanks for all the input guys it is invaluable in helping me learn and mold this project into something more realistic.

 

[zerodayjames]

Also I am not seeing any MTR3000s for better than $2000.00... Any resources to used radio sellers would be awesome.

 

[MTS2000des]

Have you checked with your state or regionwide repeater coordination council? You just can't put an Amateur Radio repeater on the air unless you are coordinated. I would check with them, and see if there are any UHF or VHF repeater pairs available. Putting something haphazardly on the air could result in being ordered off that frequency, especially if you haven't done your research.

Not totally true. Amateur repeater coordination is not an FCC requirement, while recommended, a licensee can still put up a repeater without it. If interference with a coordinated repeater does occur, the FCC usually sides with the coordinated system vs. uncoordinated, but nothing in the rules makes it mandatory unlike part 90.

 

[MTS2000des]

I will be scrapping the use of two antennas and opt for a duplexer on the taller tower. I also plan to extend this tower another 10 ft. to bring it to a total height of 40 ft. not including the height of the antenna. When I do this I also plan to replace the Tram with a Hustler G6-440.

You must understand that transmitting into the same antenna you receive on is a much different world than using separate TX and RX. Duplexer tuning is CRITICAL for performance and it takes skill, knowledge and real test equipment to set one up properly. Everything in line becomes a part of the equation including the choice of antenna, feedline, grounding- all of it plays a part in how well (or how poorly) a duplexed system performs.
Setting up repeaters isn't just a matter of "buy this and buy that" and throw it together. For it to work well, one has to do a lot of on site optimization and tweaking.
Repeaters are like boats: Bust Out Another Thousand here and there and keep feeding it money. Ask me how I know.

 

[mmckenna]

Wanted to just update my original post but not sure if that's an option so I'll post it here.

Current setup: (Keep in mind I am changing this up quite a bit)

OK, that explains the issues you are seeing. Horizontal/Vertical separation isn't enough and your receiver is getting desensed when the transmitter is running.

I also considered renting space on a site. This would solve all my issues as there are repeaters on there currently that I am able to hit and get to where I want. But I haven't looked into all the costs and honestly would prefer to self host.

Any decent tower site is going to come with a long list of expensive requirements to let you in the door. Insurance is a big one. Having sufficient filtering and quality feedline, antennas, filters, etc. will all be required. That'll get expensive really quick. Usually the last guy in through the door becomes the scapegoat for any issues that happen.

From what you are saying, a self hosted experimental system is the way to go. That'll take a lot of the burden off and let you do this much cheaper.

Thanks for all the input guys it is invaluable in helping me learn and mold this project into something more realistic.

40 feet antenna height is going to limit your range, to a few miles in that sort of environment. I'd not spend a ton of money chasing high power stuff unless you are going to have the money to eventually move this to a higher radio site.


MTR3000 at $2000 is a lot of money, unless it is coming with good duplexers. You can get new DMR repeaters for less than that.

 

[kayn1n32008]

I have two Wouxon KG-UV980P mobile radios setup in repeat mode... Antennas have 40 ft. of horizontal separation and 10 ft. of vertical separation.

Problem number one is the Wouxon radios. They have garbage receivers.

Problem number 2 is 40ft. of horizontal separation.

Vertical, with zero horizontal separation will provide much better isolation between Rx and Tx.