BUILDING A REPEATER
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CATAWBA911
- Posts: 55
- Joined: Tue Nov 27, 2001 4:00 pm
THE VOL FIRE DEPARTMENT I AM ON IS GOING TO BE PUTTING IN A REPEATER TACTICAL CHANNEL. I AM LOOKING AT USING A GR1225, A DUPLEXER, AT LEAST 7/8" HARDLINE, AND SOMETYPE OF GOOD ANT. ON A 50' TOWER. CAN ANYONE GIVE ME SOME GOOD IDEAS FOR WHAT NAME BRANDS AND MODEL NUMBERS THAT I NEED TO USE. MY TOTAL PRICE RANGE IS SOMEWHERE AROUND $4000.00 CAN I DO THIS???
It would help if you gave just a few more details. You did not mention the frequency range your planning to use. What type of coverage are you expecting the repeater to have. What part of the country are you in? This will effect the antenna selection and coverage issues.
There has been a good discussion on antennas in another item here on this page. You might want to go and read it. It would save a great amount of time and space for us all.
If this is for the public safety use, then you want to also consider the backup power issue for the repeater. A revert to 12 volts is nice when the power goes out and the generator didn't start. Remember the radio needs to work when nothing else is.
Jim
There has been a good discussion on antennas in another item here on this page. You might want to go and read it. It would save a great amount of time and space for us all.
If this is for the public safety use, then you want to also consider the backup power issue for the repeater. A revert to 12 volts is nice when the power goes out and the generator didn't start. Remember the radio needs to work when nothing else is.
Jim
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CATAWBA911
- Posts: 55
- Joined: Tue Nov 27, 2001 4:00 pm
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Tom in D.C.
- Posts: 3859
- Joined: Tue Sep 04, 2001 4:00 pm
- What radios do you own?: Progreso soup can with CRT
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CATAWBA911
- Posts: 55
- Joined: Tue Nov 27, 2001 4:00 pm
HI:
Just to insure you get the main body
of information since you indicated a
email problem.
As in the Email, I have been setting
up repeater sysetms for over 25 Years
and its definately a good idea to seek
out the best for your bucks.
A Good VHF Antenna should be chosen
in relation to Height Above ground level
and how far away the Users are.
Depending on you local weather problems, Antennas can range from a couple of hundered
dollors for Antenex/PD types to 1000.00 for
Super Station Masters/ Celwave / DB Products.
7/8" Transmission line ( Perfect ) for your
application.
A good Suitable Duplexer will be well worth
the Investment as you will have only ( 1 )
Antenna and ( 1 ) piece of transmission line
to deal with
Properly Installed, a good Antenna will make
a Handie-Talkie sound like a Base station
With Respects to Radios, GM300's / Maxtracs
and Radius Mobiles make Excellent Cost Effective Repeaters. Easy to Service ( when and if a problem occurrs ). Personally I like the GR300's for cost effective repeaters/
Want to move up to something a bit more Powerfull? MSF5000's/MSRs, Quintars are not
a bad idea either if you can afford them.
Need High-Power? and something easy to Fix, Micors are not a bad choice either.
With Some receievr Mods, they work great.
Other than perhaps a battery Back-up for your system, you should be able to get a
pretty nice system for your budget allowance.
If you wish, contact me direct, and I am more
than happy to give you some sound advice or if you wish, I have most of the stuff you need in stock @ the warehouse.
Monty
<font size=-1>[ This Message was edited by: [email protected] on 2002-03-20 14:02 ]</font>
Just to insure you get the main body
of information since you indicated a
email problem.
As in the Email, I have been setting
up repeater sysetms for over 25 Years
and its definately a good idea to seek
out the best for your bucks.
A Good VHF Antenna should be chosen
in relation to Height Above ground level
and how far away the Users are.
Depending on you local weather problems, Antennas can range from a couple of hundered
dollors for Antenex/PD types to 1000.00 for
Super Station Masters/ Celwave / DB Products.
7/8" Transmission line ( Perfect ) for your
application.
A good Suitable Duplexer will be well worth
the Investment as you will have only ( 1 )
Antenna and ( 1 ) piece of transmission line
to deal with
Properly Installed, a good Antenna will make
a Handie-Talkie sound like a Base station
With Respects to Radios, GM300's / Maxtracs
and Radius Mobiles make Excellent Cost Effective Repeaters. Easy to Service ( when and if a problem occurrs ). Personally I like the GR300's for cost effective repeaters/
Want to move up to something a bit more Powerfull? MSF5000's/MSRs, Quintars are not
a bad idea either if you can afford them.
Need High-Power? and something easy to Fix, Micors are not a bad choice either.
With Some receievr Mods, they work great.
Other than perhaps a battery Back-up for your system, you should be able to get a
pretty nice system for your budget allowance.
If you wish, contact me direct, and I am more
than happy to give you some sound advice or if you wish, I have most of the stuff you need in stock @ the warehouse.
Monty
<font size=-1>[ This Message was edited by: [email protected] on 2002-03-20 14:02 ]</font>
-
CATAWBA911
- Posts: 55
- Joined: Tue Nov 27, 2001 4:00 pm
One item that I don't think anyone here has mentioned in some time is the coax jumper cables. Use the best you can get your hands on. Don't use RG-8 type cable with single shielding. It leaks too much and will cause system noise proiblems. Try and use double shielded or heliax type cable for all the jumpers.
The cost of the duplexer will depend on the spacing between the TX and RX frequencies. The more the better. If you don't have the 3 Mhz or so available, you might as well plan on spending $800 to $1500 for just the duplexer. You can get about 30% off the list price if you purchase it direct with a municipal payment. There are several companies that will work with you. You just have to ask for the discount.
Try and get a tone squelch radio to monitor the frequencies you plan to use. Need to find a quiet one if you can. Also play with the tone squelch tones to find one that is not used on those frequencies if you can.
Don't forget the frequency coordination and all the papers that go with it. Cost money to get past the frequency cooordinator. You may do better in changing a license that you have already than going for a new on.
Just a few more thoughts for the gray matter and the site selection of equipment.
Jim
The cost of the duplexer will depend on the spacing between the TX and RX frequencies. The more the better. If you don't have the 3 Mhz or so available, you might as well plan on spending $800 to $1500 for just the duplexer. You can get about 30% off the list price if you purchase it direct with a municipal payment. There are several companies that will work with you. You just have to ask for the discount.
Try and get a tone squelch radio to monitor the frequencies you plan to use. Need to find a quiet one if you can. Also play with the tone squelch tones to find one that is not used on those frequencies if you can.
Don't forget the frequency coordination and all the papers that go with it. Cost money to get past the frequency cooordinator. You may do better in changing a license that you have already than going for a new on.
Just a few more thoughts for the gray matter and the site selection of equipment.
Jim
Hi
You may want to consider an R1225 series repeater.
All the repeat functions are built into the unit so there is no external controller needed. Wide/Narrow band, nice big heat sink, higher duty cycle than a GM300.. etc.
Stick it into a GR500 cabinet, add the back-up battery and duplexer.... it makes a nice setup for alot of applications.
Just my 2 cents.
Bruce
You may want to consider an R1225 series repeater.
All the repeat functions are built into the unit so there is no external controller needed. Wide/Narrow band, nice big heat sink, higher duty cycle than a GM300.. etc.
Stick it into a GR500 cabinet, add the back-up battery and duplexer.... it makes a nice setup for alot of applications.
Just my 2 cents.
Bruce
Wy pay all the money for the GR500 cabinet?
Just mount the R1225 radio chassis verticaly with the standard Maxtrac/Radius mobile bracket on a 19 inch relay rack pannel with the heat sink facing up. You do not even need to buy the "dash board" for the R1225, just install one jumper and away you go. In place of the "dash board" , a very simple connector with a mic jack on it for programming and testing. There is even room for a power supply and put the duplexer on the other side. If you will be running lots of power, then add TWO fans on the heat sink with a thermostat. We have several in operation and they work just as well as the whole enchalada GR500 except the cost is MUCH less AND less dirt because the fan only runs when it gets hot. I can get a parts list for the ones we have if you need.
Just mount the R1225 radio chassis verticaly with the standard Maxtrac/Radius mobile bracket on a 19 inch relay rack pannel with the heat sink facing up. You do not even need to buy the "dash board" for the R1225, just install one jumper and away you go. In place of the "dash board" , a very simple connector with a mic jack on it for programming and testing. There is even room for a power supply and put the duplexer on the other side. If you will be running lots of power, then add TWO fans on the heat sink with a thermostat. We have several in operation and they work just as well as the whole enchalada GR500 except the cost is MUCH less AND less dirt because the fan only runs when it gets hot. I can get a parts list for the ones we have if you need.
We put the little TO220 style thermostats on the heat sinks too, they work very nicely.
I agree with you that the GR500 is not the least expensive box, however as a dealer, most customers like to see a nicely packaged unit..
After all if cost was everything, we'd all be driving a welding shop car. I know I could put together 4 wheels, an engine and and a chair for whole lot less than I just paid for my new car! It would still get me from A to B.
We managed to pick up some cabinets at a great price, that were made for fixed satellite phones. They were brand new still in the boxes with DIN rails mounts inside. We've put together a few nice systems with them.
Cheers
Bruce
I agree with you that the GR500 is not the least expensive box, however as a dealer, most customers like to see a nicely packaged unit..
After all if cost was everything, we'd all be driving a welding shop car. I know I could put together 4 wheels, an engine and and a chair for whole lot less than I just paid for my new car! It would still get me from A to B.
We managed to pick up some cabinets at a great price, that were made for fixed satellite phones. They were brand new still in the boxes with DIN rails mounts inside. We've put together a few nice systems with them.
Cheers
Bruce
Perthcom, where did you get your TO220 thermostats and what calibration/tempature rating?
I am going to build some more pannels for R1225 chassis soon. Some time back there was a discussion on someone plugging into someone elses radio and reprogramming it at a remote site repeater ect. That was another reason NOT to have the "dash board" on the R1225 radio. A very simple cable is used by the tech to test and program.
PS I would like to find a way to remove the "dash boards" on GM series radios in repeaters to aliviate that problem and save current drain at a battery/solar site, any ideas?
I am going to build some more pannels for R1225 chassis soon. Some time back there was a discussion on someone plugging into someone elses radio and reprogramming it at a remote site repeater ect. That was another reason NOT to have the "dash board" on the R1225 radio. A very simple cable is used by the tech to test and program.
PS I would like to find a way to remove the "dash boards" on GM series radios in repeaters to aliviate that problem and save current drain at a battery/solar site, any ideas?
Hi
I got them from Newark, I can look up the P/N at the office and email it to you..
they work quite nicely.
As far as the GM300, I've never tried running one without the front cover...
Something tells me the pullups for the push buttons are on the front display panel.. i'll have to pull at manual and look
Bruce
I got them from Newark, I can look up the P/N at the office and email it to you..
they work quite nicely.
As far as the GM300, I've never tried running one without the front cover...
Something tells me the pullups for the push buttons are on the front display panel.. i'll have to pull at manual and look
Bruce
If you want to use Maxtrac, Radius M100-216 or GM series radios, look at this repeater interface module, $115 with all the options, and works on five pin radios.
http://www2.4dcomm.com/metrotech/cw_img2.jpg
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http://www2.4dcomm.com/metrotech/cw_img2.jpg
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