MSR2000 & Narrowband

[n9upc]

Alex or mods: sorry if this is in the wrong forum.

Here is my situation:
Our ambulance service is in the process of setting up a repeater for us medics to use in addition to using it as an admin channel. So the quest for a repeater pair begins.

We contacted the state APCO cord and asked for a wide band channel and we would like it to be 100 watts (this is based upon the terrain and lay of the land.)

They found us a wide band channel but then the problems started to happen. We then found out that the city to the north of us is looking for a repeater channel for there use also which is not a big deal. But, now we found out that they may issue us the same repeater pair even though we are only about 15 miles apart to the both of us. Holy nightmare peter pan.

When asked why they would do that the response was that both of us asked at the same time and since we both want it for medical comms they would issue us the same.

The problem is that we would be doing paging and other issues over this channel and so would they which would cause some problems, not to also mention who gets taken down when there is interference issues.

So back to the drawing board we went and re-evaled our equipment. Narrowband may be an option (but we would have to upgrade a s*#t load of portables which is why we wanted wide band) but it comes down to our donated MSR2000 repeater.

Can an MSR2000 be converted to meet the 12.5 Khz deviation requirement which we may have to go with in order to get a repeater pair for us.

Now before people start asking we can not share with the other town on the repeater. We thought about doing a poor mans wide area coverage with both repeaters the same PL out, but a different PL in for each repeater. But then who gets to use the repeater first and when becomes a major issue which we do not have time to deal with.

Also NO we do not have the money for a new repeater. If we did not have this one donated to us then this would not even be possible. The money was not in the budget this year or next, but since we have the equipment we thought it might be time to move on it.

So can a MSR2000 do narrowband????

[wavetar]

The repeater has both 'transmit' and 'repeat' deviation adjustments, so I don't see why it couldn't be adjusted to put out a good narrowband transmit audio at 2.5KHz max, when receiving a narrowband signal. It won't be as selective as a 'true' narrowband receiver, but it shouldn't matter as long as there isn't someone on another narrowband frequency 12.5KHz away blasting into it as well (which the FCC shouldn't allow anyway). Your main issue is going to be replacing all of your field radios.

Todd

[RADIOMAN2002]

Narrow banding most equipment is just a matter of turning down the TX deviation, both PL and audio. The FCC doesn't regulate Rx'rs. Now for the most part this is very simple, the problem comes in when you want both wide and narrow in the same radio.
Sure you could lower the TX audio, and use it on a wide band channel, but the audio will be low and the PL almost non-existant. Meaning that it might not open some radios, or repeaters.
I find it very strange that the coordinator is putting you both on the same channel, that usually doesn't happen unless it is going to use under mutual aid. Go back to the coordinator and ask specifically why and in writing. The purpose of a coordinator is to prevent interference, here they are taking your money and not giving you what you want.
You didn't specify what the channel was that you are getting, is it a MED channel (1-10) or a VHF MED. The UHF Meds are still wide band and that may be why you both are getting it. If they other town is getting Med 10 you should try for Med 9, or even ask for the old telemetry channels. If the coordinator refuses go to a diffenent one. There is no longer any exclusivity for coordination on channels.
The last I heard was that the FCC is now limiting channel assignment to prevent hoarding of frequencies, even by Public Safety, there are ways around it, it just take some perserverence to get what will work for you, not something the coordinator thinks you need.

[Will]

There is a kit that has the nessary crystal filters for the receiver and other parts needed to 'narrow band' a MSR. Typical cost is $15 to $25 ea. The transmitter deviation MUST be set using a calibrated service monitor and needs to be documented in the station records (FCC req.) cya.

Comunication Specialists in Orange, CA., founded by a vol. fireman a loooong time ago!

http://www.com-spec.com

1-800 854-0547