Repeater Building 101

[PastorGary]

New member Earl mentioned the fine Kenwood TK-805d radios in a review thread.

 

Just wondering out loud:   Is it possible to use two Kenwood radios to construct a good quality repeater?   I have seen this done with a few Motorola models, but not so much from the Kenwood line.

 

If anyone has experience in setting up home-brew repeaters made from Kenwood equipment, please let us know what's involved regarding >  model numbers, cabling, accessories, programming, duplexer set up and interfaces if needed. 

 

Thank you.

[Guest spd641]

P-G,

Yes it is,I have watched a youtube video where someone actually did this,here is the video of a completed repeater.http://www.youtube.com/watch?v=pFVkczJKzVA also  here is the link where you get the instructions to build it. http://www.repeater-builder.com/kenwood/pdfs/tk-805-wiring.pdf

[Unit61]

Since this topic is so labeled as Repeater Building 101 I figured this would be a good place to place this post as it relates to repeater building.

I have recently obtained an RF Signal Generator as well as a Spectrum Analyzer for radio work. I am able to do duplexer tuning with this equipment. If anyone needs duplexers tuned PM me and we can work out the shipping and tuning details.

[cwheeler]

For our PLMR use, we have used "range extenders" with the TK-790 and TK-890 mobiles.  These are simply cross band repeater setups.  The 25 pin interface on the back of the radios has everything needed (COS, PTT, audio in both directions.) to connect to another radio.  For us, the extender was a 1 watt Pyramid that was powered by the Kenwood trough the interface cable.  The only modification we had to do was add a surface mount fuse in the Kenwood to protect the power suppy output to the other radio.

 

Don't see any reason why a couple of TK-890 rigs couldn't be tied back to back and each run to separate antennas or a duplexer.

 

We have phased out nearly all the conventional VHF and UHF radios in our fleet since we have rolled out a 450MHz trunked system, so I have not done much work on these things lately.  I can get the documention next week when I go back to work.

 

I don't know that the TK-890 is part 95 certified.  You'd have to use your own judgement here...

 

As mentioned above I have seen many Motorola mobiles used as repeaters.  Many of their old mobiles could be converted easily to full duplex repeater operation; only one radio required.

 

I built a portable, low power repeater in a suit case once with a couple of Motorola Maxtracs.  With the power down at 5 watts it was easy to a small duplexer package.  I think it was a Sinclair, but it was 20 years ago so my memories of all the component brands we used is a little fuzzy.

 

Hey does anyone know if the Motorola MSF-5000 is a part 95 certified repeater/base?  A while back I had a couple offered to me.  Man, I loved those.  How about the Ericsson/GE Mastr III ?   I know people that know people... that have surpluses of this stuff.  Since I haven't been an active ham in a long time, I have turned down opportunities to get some of these things for really cheap if not free, but didn't want to add any more junk to my garage.

 

Curtis

[ImTheGuy]

For our PLMR use, we have used "range extenders" with the TK-790 and TK-890 mobiles.  These are simply cross band repeater setups.  The 25 pin interface on the back of the radios has everything needed (COS, PTT, audio in both directions.) to connect to another radio.  For us, the extender was a 1 watt Pyramid that was powered by the Kenwood trough the interface cable.  The only modification we had to do was add a surface mount fuse in the Kenwood to protect the power suppy output to the other radio.

 

Don't see any reason why a couple of TK-890 rigs couldn't be tied back to back and each run to separate antennas or a duplexer.

 

We have phased out nearly all the conventional VHF and UHF radios in our fleet since we have rolled out a 450MHz trunked system, so I have not done much work on these things lately.  I can get the documention next week when I go back to work.

 

I don't know that the TK-890 is part 95 certified.  You'd have to use your own judgement here...

 

As mentioned above I have seen many Motorola mobiles used as repeaters.  Many of their old mobiles could be converted easily to full duplex repeater operation; only one radio required.

 

I built a portable, low power repeater in a suit case once with a couple of Motorola Maxtracs.  With the power down at 5 watts it was easy to a small duplexer package.  I think it was a Sinclair, but it was 20 years ago so my memories of all the component brands we used is a little fuzzy.

 

Hey does anyone know if the Motorola MSF-5000 is a part 95 certified repeater/base?  A while back I had a couple offered to me.  Man, I loved those.  How about the Ericsson/GE Mastr III ?   I know people that know people... that have surpluses of this stuff.  Since I haven't been an active ham in a long time, I have turned down opportunities to get some of these things for really cheap if not free, but didn't want to add any more junk to my garage.

 

Curtis

Hey Curtis,

I found the Motorola MSF-5000 to be Part 95 certified. Good raves about this repeater/base all over the net.

[WQUJ877]

I am a newbie and would like to set up a repeater. Most information I find is more than I can handle. Is there a GMRS repeater setup I can purchase rather than build?

 

Thanks

[JohnE]

look on ebay, there are sellers out here who will set freq's tones and tune duplexer for you. all you'll need after that is an antenna ,cable and a place to put it.

[WQUJ877]

Thanks. John E

[PastorGary]

Hi, Matthew - Welcome to the MyGMRS forum...  Hope that you get all the information that you need to set up your system.

[zap]

I looked at building some out of TK880's but I couldn't find the little pigtail anywhere (I guess Kenwood's version of the OPC-617 that my Icom's use). 16 pin Moto's are easy, $10 cable from China, programming the pinouts and you are GTG (minus the duplexer/antenna setup).

 

It's very rare to see low duty repeaters in commercial operation that aren't based off of mobile radios. Especially in applications where a desktop unit isn't needed (GE MASTR II and Kenwood TKR desktop units). The Icom CY-series of repeaters are mobile based as are the GR series from Motorola (GR1225 excluded), think I've even seen a GR style from Moto based off the CDM line. 

 

Two mobiles can be put together to form a repeater. In some cases with older (crystal controlled) mobiles, you can actually make the receiver and transmitter run full duplex and convert a mobile to a repeater. Examples of this are Motorola Micor, GE MASTR II, Motorola Mietrek…

[quarterwave]

I have built more than one repeater from a couple of Motorola Radius or Maxtrac mobiles. The best cables I have found are from MRE1032 on ebay. The simple one has audio level control and optional delay. I have made my own cable also, it's easy. 

 

I actually used a couple of Maxtrac's and a cable I made up in 10 minutes back about 20 years ago when I was working for M and our local city service departments' GE VHF repeater went kaboom on a summer day. Hooked the mobiles up to their duplexer, and made them a temporary 20 watt repeater. They actually wanted to keep it...I think it worked better than the old GE. 

 

I have seen the old "Industrial" MSF5000 repeaters...big cabinet, all the regular heavy duty internals...and a 6 watt PA.  

[zap]

 

I have seen the old "Industrial" MSF5000 repeaters...big cabinet, all the regular heavy duty internals...and a 6 watt PA.  

 

Makes me feel good inside about my Micor with a 12W PA. And then there's the one I have with a 100W PA.

[quarterwave]

Well...Micor was getting old when I was working for M and Motrac was ancient! Heck...MSR was current but on the way out at that time. 

 

Anyone remember the difference between Motrac and Motran? 

[zap]

Well...Micor was getting old when I was working for M and Motrac was ancient! Heck...MSR was current but on the way out at that time. 

 

Anyone remember the difference between Motrac and Motran? 

 

Negative ghost rider. All of my purpose built repeaters are older than I am. My newest two are R100's.

[WQUX891]

all you'll need after that is an antenna ,cable and a place to put it.

Speaking on a place to put it; I'm a newbie to GMRS as well.  If I were looking to find a place for my repeater, how would I start?  I know of a few repeaters in my area that are on highrise buildings, mountain top sites sharing with ham/commerical, etc.  How have some of you secured sites in the past?  If there is a "lot rent," what would be a reasonable "rent" for a site?  This topic has always interested me, but I wouldn't have the first clue where to start.

 

Thanks!

Travis 

[zap]

Speaking on a place to put it; I'm a newbie to GMRS as well.  If I were looking to find a place for my repeater, how would I start?  I know of a few repeaters in my area that are on highrise buildings, mountain top sites sharing with ham/commerical, etc.  How have some of you secured sites in the past?  If there is a "lot rent," what would be a reasonable "rent" for a site?  This topic has always interested me, but I wouldn't have the first clue where to start.

 

Thanks!

Travis 

 

 

I usually just ask the building or tower owners first. Explain what you'd like to do. Sometimes you can get away with not having to pay anything…sometimes you have to pay something. It helps when you have ties to a radio shop or county emergency coordinator.

[MSensei]

On topic, but regarding licensing - if I were to build a repeater, would I acquire a separate license for the repeater or would I use my current GMRS license?

[zap]

On topic, but regarding licensing - if I were to build a repeater, would I acquire a separate license for the repeater or would I use my current GMRS license?

 

Nope. Operation technically falls under your license under current rules. 

[Steve]

this is a great thread, i'm also new to GMRS and i have a lot of the same questions.

 

i have a thread for my build using Kenwood TK-880 radios (I still am at the time of this post).  I have looked at so much gear, even the R100.   It gets to a point where i'm not sure if its better to build from a pair of mobiles and learn a bunch, or just get something already set up and just use it.

 

https://forums.mygmrs.com/topic/333-building-a-repeater-out-of-two-kenwood-tk-880/

 

I dont want to get too ahead of myself until i see how far this will go just using a roof antenna.  If i can give my kids an HT and it will reach to the school like 2 miles away, then that would really be cool.  The terrain is the problem... lots of little hills everywhere, and the school is on the other side of a hill.  Location will be the biggest factor i think. 

[Steve]

Negative ghost rider. All of my purpose built repeaters are older than I am. My newest two are R100's.

how do you like your R100s? I'm looking at one on ebay now but the price is still higher than home made, AND i'm worried that if something breaks, its a lot harder to get parts and fix than just swapping out a TX-880 inside a home made box.   Modular seems to be more fun and i'm learning so much doing it myself.   I just ordered a box of Anderson Power Pole connectors and in line fuses.  This project cost is really adding up. 

[zap]

how do you like your R100s? I'm looking at one on ebay now but the price is still higher than home made, AND i'm worried that if something breaks, its a lot harder to get parts and fix than just swapping out a TX-880 inside a home made box.   Modular seems to be more fun and i'm learning so much doing it myself.   I just ordered a box of Anderson Power Pole connectors and in line fuses.  This project cost is really adding up. 

 

I've had them both for about a year and still haven't gotten a computer slow enough to program them. Haven't even built a programming cable for them either. R100's versus a GR500 (same size cabinet just with two GM300's and a RICK inside)…the R100 has a much narrower passband filter on the receiver (it's about 1-2 MHz wide) where the GR500's GM300's has a receiver passband roughly 40 MHz wide (similar with most mobiles). 

 

They need a 486 or slower to program…they come in either PL or DPL (unlike GM300's which can do both). The thing they do offer over other radios, when they get to hot…they move to reserve power. Factory settings, a 10W goes down to 2W and a 25W goes to 10W (this can all be configured though). I lucked out as both of mine have the DB25 accessory connector on the outside. They are even setup for battery backups.

[WQUX891]

I usually just ask the building or tower owners first. Explain what you'd like to do. Sometimes you can get away with not having to pay anything…sometimes you have to pay something. It helps when you have ties to a radio shop or county emergency coordinator.

Cool.  It sounds like such a rudimentary question, but I wasn't sure how other's experiences were.  

 

Thanks!

[Steve]

Cool.  It sounds like such a rudimentary question, but I wasn't sure how other's experiences were.  

 

Thanks!

I'm wondering the same thing.   I found a house at the very top of a hill overlooking the camp ground that we're going to be at this summer, you can see for miles from his back yard.  I called him up and he didn't understand what I wanted to do.   He told me he's okay with it, but not sure if there will be a plug to plug in outside, so i should bring some solar panels just to be safe.   Now i'm wondering if its better to set up two HTs vs two Mobiles just to reduce the standby power.   This is turning into a big project of learning the pros and cons of using cheap HTs vs commercial mobile systems, batteries, solar panels, controllers, charge controllers, location, and how much is too much weight to carry when sizing it up with batteries.