I am requesting information regarding the establishment of a local repeater for a volunteer fire department.
I have seen in this forum advice about the Motorola RICK and a plug 'n play device from "Wil?"
Just to be sure I am no radio expert but do have a good understanding of the fundamentals of two way communicaitons.
Wil's plug 'n play seems like the easiest device to employ. However, I need to know what kind of duplexer to employ in this scheme and how difficult it is to install and tune this duplexer. Would I need any other hardware besides the radios, the plug 'n play and the duplexer?
I realize we will have to coordinate another frequency to fully implement this system. Our present system is working on frequency 151.160.
Any advice on this subject will be greatly appreciated.
Local Repeater for Fire Department
Moderator: Queue Moderator
You need to know what your assigned freqs. will be before you can determine what type duplexer will be needed, generally the closer they are spaced = more money. Tuning a duplexer is not difficult, but requires fairly expensive equipment that you probably do not have readily available. The new assigned freq. may affect other things as well such as the antenna.
My advice is don't try to do this based solely on correspondence here- the job will go much faster/smoother if you can find a reputable local tech and talk about it.
My advice is don't try to do this based solely on correspondence here- the job will go much faster/smoother if you can find a reputable local tech and talk about it.
If your determined to put a repeater into operation, the first step is to get a second frequency for the repeater input. Make sure you get one that is at least 1 Mhz. away from your present one. This will keep the cost of the duplexer down. Duplexers will cost you some place between $700 and $1800.
You will need to go through a frequency coordinator. There are several that you can work with. Do a search on the web for radio frequency coordinators. You will find APCO and the fire service one, whoe's name I can't think of right now.
Anyway, they will charge you between $180 and $220 per frequency, per location. To make this more clear, you need the repeater output frequency (your present frequency) and and input mobile license. If you have a remote dispatch location, it then becomes a control station. If the antenna can be below 6.1 meters, it doesn't have to be licensed. So you end up with just 3 lines on your application. The repeater transmitter, mobile on the existing channel for talkaround and a third line for the mobiles on the repeater input.
Why the talkaround (output frequency), you ask. Well what happens if the repeater goes down? With the talkaround or simplex, you can keep on talking. Everyone will still hear you if your close enough. Second, if you get out on the fringe of the repeater coverage, you can talk between units and not have to worry about "I couldn't make out what you said". You will actually jam each others receivers when some distance from the repeater and in close range to each other.
Hope this starts you out in the right direction. Depending on the age of your antenna installation you may aor may not be able to use it for the repeater. Old antanna systems can cause all sorts of noise problems for a repeater.
Jim
You will need to go through a frequency coordinator. There are several that you can work with. Do a search on the web for radio frequency coordinators. You will find APCO and the fire service one, whoe's name I can't think of right now.
Anyway, they will charge you between $180 and $220 per frequency, per location. To make this more clear, you need the repeater output frequency (your present frequency) and and input mobile license. If you have a remote dispatch location, it then becomes a control station. If the antenna can be below 6.1 meters, it doesn't have to be licensed. So you end up with just 3 lines on your application. The repeater transmitter, mobile on the existing channel for talkaround and a third line for the mobiles on the repeater input.
Why the talkaround (output frequency), you ask. Well what happens if the repeater goes down? With the talkaround or simplex, you can keep on talking. Everyone will still hear you if your close enough. Second, if you get out on the fringe of the repeater coverage, you can talk between units and not have to worry about "I couldn't make out what you said". You will actually jam each others receivers when some distance from the repeater and in close range to each other.
Hope this starts you out in the right direction. Depending on the age of your antenna installation you may aor may not be able to use it for the repeater. Old antanna systems can cause all sorts of noise problems for a repeater.
Jim
The other coordinating group you're thinking of is IMSA. I've found them to be most accommodating.
A slight correction: small control stations do require their own line on the 601, but do not require a location for each one. Create a line, specify the number of small control stations and their max power, and then define their service as "Control Stations meeting the provisions of 47 C.F.R. sec. 90.119(b)."
(The regulation provides:
"If the control station(s) will operate on the same frequency as the mobile station, and if the height of the control station(s) antenna(s) will not exceed 6.1 meters (20 feet) above ground or an existing man-made structure (other than an antenna structure), there is no limit on the number of such stations which may be authorized. Appropriate items on FCC Form 601 shall be completed showing the frequency, the station class, the total number of control stations, the emission, and the output power of the highest powered control stations.")
Note that this provision for the simple licensing of small control stations does not apply to sub-part L frequencies (i.e., 470 mHz through 512 mHz).
A slight correction: small control stations do require their own line on the 601, but do not require a location for each one. Create a line, specify the number of small control stations and their max power, and then define their service as "Control Stations meeting the provisions of 47 C.F.R. sec. 90.119(b)."
(The regulation provides:
"If the control station(s) will operate on the same frequency as the mobile station, and if the height of the control station(s) antenna(s) will not exceed 6.1 meters (20 feet) above ground or an existing man-made structure (other than an antenna structure), there is no limit on the number of such stations which may be authorized. Appropriate items on FCC Form 601 shall be completed showing the frequency, the station class, the total number of control stations, the emission, and the output power of the highest powered control stations.")
Note that this provision for the simple licensing of small control stations does not apply to sub-part L frequencies (i.e., 470 mHz through 512 mHz).