hi guys,
I looked for a link in the search menu but I did not find what I need so it's time to ask the experts
I want to build a repeater that I can use for my business, I have a tower that I can use but I don't know what type of equipment I need.
can I use 2 mobile radios and a rick and a duplexer to get a repeater or would i need to use a gr100 or someting like that, if I use the 2 mobles what would be better gm300'2, m1225's, sm120's maxtracs.
if any body could give me a little help or point me to a link in batlabs that would be great.
thanks jeffrey
newbie repeater help
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J_L_COHEN
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- What radios do you own?: Xtl5000 apx7000 Cdm1550,Ht1250
newbie repeater help
Jeffrey Cohen
Captain/Communications Officer
Newton Township Fire & Ems
Zanesville, Ohio
! SMOKE DETECTORS SAVE LIVES !
Captain/Communications Officer
Newton Township Fire & Ems
Zanesville, Ohio
! SMOKE DETECTORS SAVE LIVES !
Repeaters are expensive, no matter what route you go, more so than most folk realize at the beginning of a project. My advice is to plan the project through before you start spending money, in order to minimize wasting some of it and being disappointed at the result.
A repeater consists of: a receiver, a transmitter, a controller (which handles decoding and encoding of PLs or DPLs and audio routing, plus (if you use them) wireline interfaces), an antenna, feedline, tuned filtering devices (duplexers, multicouplers, combiners, and the like, depending on site requirements), and power sources.
There are basically three routes you can follow. The low end route would use two mobile radios, one of which serves as the receiver and the other the transmitter, which are connected by a separate controller. The controller can be a sophisticated one (handling signaling functions and auto processing) or a simple one (which would remit decode to the receiver and encode to the transmitter, and function primarily as a simple routing box for the audio line and keying signal). Any filtering is handled by separate units, as is the question of power supplies.
The intermediate route is an "all in the box" solution. I'm not familiar with the Kenwood TK-750, but I've installed some older TK-720s in situations where budget was a constraint and frankly they've been work horses. These boxes contain separate transmitters and receivers and an array of control functions all in a table-top or rack-mount box. Any filtering is handled externally.
The high end route would be a dedicated professional (or public safety) grade machine, such as the MTR2000 or Quantar. You pay a lot more but you get superb receiver performance, a transmitter with more power and a better duty cycle, and a lot of other features.
The driving factors are budget, the requirements of the site (many do not permit anything but high end machines because they are concerned about inter-machine interference within the site), and duty-cycle requirements.
Once you've made your decision about which path to follow, I'd design out the entire system, from electric plug to antenna tip, and then consult with both a guy who does repeater installs and servicing, for some helpful hints, and the site manager, to be sure your design will be acceptable at his site.
For my money, I'd avoid the low end solution. Making a repeater out of two mobiles sometimes works great in a temporary installation, but over the long haul you're asking more out of the mobile radios than they were designed to give, and they will fail or perform poorly. If budget is a constraint, I'd look hard at the Kenwood table-tops. Do not scrimp on the duplexer (assuming you can run into your own stick); bucks spent here will pay off in machine performance.
Finally, you should be realistic in your expectations about machine performance. A lot of folks fail to realize that you can spend real money and pump out some impressive ERPs, but if terrain, HAAT and manmade obstructions are in the way, the performance of the system will be limited.
A repeater consists of: a receiver, a transmitter, a controller (which handles decoding and encoding of PLs or DPLs and audio routing, plus (if you use them) wireline interfaces), an antenna, feedline, tuned filtering devices (duplexers, multicouplers, combiners, and the like, depending on site requirements), and power sources.
There are basically three routes you can follow. The low end route would use two mobile radios, one of which serves as the receiver and the other the transmitter, which are connected by a separate controller. The controller can be a sophisticated one (handling signaling functions and auto processing) or a simple one (which would remit decode to the receiver and encode to the transmitter, and function primarily as a simple routing box for the audio line and keying signal). Any filtering is handled by separate units, as is the question of power supplies.
The intermediate route is an "all in the box" solution. I'm not familiar with the Kenwood TK-750, but I've installed some older TK-720s in situations where budget was a constraint and frankly they've been work horses. These boxes contain separate transmitters and receivers and an array of control functions all in a table-top or rack-mount box. Any filtering is handled externally.
The high end route would be a dedicated professional (or public safety) grade machine, such as the MTR2000 or Quantar. You pay a lot more but you get superb receiver performance, a transmitter with more power and a better duty cycle, and a lot of other features.
The driving factors are budget, the requirements of the site (many do not permit anything but high end machines because they are concerned about inter-machine interference within the site), and duty-cycle requirements.
Once you've made your decision about which path to follow, I'd design out the entire system, from electric plug to antenna tip, and then consult with both a guy who does repeater installs and servicing, for some helpful hints, and the site manager, to be sure your design will be acceptable at his site.
For my money, I'd avoid the low end solution. Making a repeater out of two mobiles sometimes works great in a temporary installation, but over the long haul you're asking more out of the mobile radios than they were designed to give, and they will fail or perform poorly. If budget is a constraint, I'd look hard at the Kenwood table-tops. Do not scrimp on the duplexer (assuming you can run into your own stick); bucks spent here will pay off in machine performance.
Finally, you should be realistic in your expectations about machine performance. A lot of folks fail to realize that you can spend real money and pump out some impressive ERPs, but if terrain, HAAT and manmade obstructions are in the way, the performance of the system will be limited.
And don't forget the appropriate federal licensing bureau, plus frequency coordination for a repeater (that uses two frequencies) vs a base station (that usually uses only one frequency). If you have to end up on a different frequency than you are now, you might have to reprogram or even replace all the radios you currently use. You may also not be licensed for the kind of power your repeater might run.
Bob M.
Bob M.
Good points.
For the base station, you don't require a license for the receive ("input") frequency, per se, but if you are licensed for FB1 and wanting to operate as a repeater, you'll have to be mod'd to FB2, and this does require coordination. You will need a license for the mobiles and portables to transmit in on the input frequency. (If the base station transmits on UHF, then the input frequency is fixed, at either 5 mHz or 3 mHz below the output.)
I'd be less concerned about mod'ing the license for increased power, since if this is an in-cabinet repeater (as I've assumed), the limiting factor on service range is going to be the receiver's ability to hear portables and mobiles, not the transmitter's ability to hit them.
For the base station, you don't require a license for the receive ("input") frequency, per se, but if you are licensed for FB1 and wanting to operate as a repeater, you'll have to be mod'd to FB2, and this does require coordination. You will need a license for the mobiles and portables to transmit in on the input frequency. (If the base station transmits on UHF, then the input frequency is fixed, at either 5 mHz or 3 mHz below the output.)
I'd be less concerned about mod'ing the license for increased power, since if this is an in-cabinet repeater (as I've assumed), the limiting factor on service range is going to be the receiver's ability to hear portables and mobiles, not the transmitter's ability to hit them.