Batboard

We are re-banding our UHF radio system to 12.5khz and are working on a calendar for reprogramming the radios. Due to the number of radios the entire system cannot be completed in one day.

Plan A is to program the portables and mobiles first then rep-rogram the bases/receivers. We realize there will be a audio issue for a few days when talking to dispatch and talkaround can be used at scenes.

Plan B Bases first then mobiles and portables.

Which is the better option?

Mark

Both ideas have negatives. You may come to realize that you end up with more than just "issues". If you have as many radios as implied, there is a good chance that you could have narrowband and wideband radios trying to talk to each other on a scene, and then neither repeater nor talkaraound will work. Some radios will fail to unmute at all when presented with too much deviation.

Is it not possible for you to program the narrowband frequencies into an additional zone in all the subscribers? Then that way you would have them all ready for the switch, and could tell them to toggle over when the bases are reprogrammed, and aside from the coverage changes (there will probably be) it should be fairly seamless. Of course, if the radios don't have enough capacity it kills that idea.

We have 1 primary dispatch center telephone line dependant, 3 fire houses with CDM1250 control stations, 25 mobiles with 38 to 64 channels per radio and 75 portables with 16 to 74 channels per portable.
Current channel setup
1 repeated 25khz primary dispatch/operations ( channel being converted to 12.5khz) 2 transmit sites 4 rx sites voted
2 direct 12.5khz
3 low power direct 12.5khz
4 low power direct 12.5khz
5 area 1 unit to unit repeater 12.5khz ( not connected to dispatch)
6 area 2 unit to unit repeater 12.5khz ( not connected to dispatch)
7 administration ( new license repeater not installed yet) 12.5khz will be connected to dispatch
We can lock out 1 transmitted and program for 12.5 and then swith the other when the field units are complete

We recently did a county wide job just as resqguy laid out - touched all the subscribers with a new zone / channels that had the narrowband channels, left the original channels where they were, and kept archives to create templates for each model of radio we found at each agency. As each agency was programmed with the narrow channels / zone, they held a training class explaining what was done. On the day of the cutover, we ran from site to site, touched the bases and repeaters, and by noon they were golden. Then, after much discussion between the parties involved, they arrived at a common channel list that was to be implemented county wide. We made the templates, and blew them into every radio. Now, every radio had the same first six channels. Some agencies were a little miffed that Their Channel was NOT number ONE in Their Radios. But! Now, when someone says "go to five", everyone including mutual aid is on the same page. On the newer radios with eleventy hundred modes, zones, scanning, ESPN, Weather, Forestry, river pilots, state police, with with with ... they got to do what they wanted to do with the remaining channels. And they could put their channel as the first mode in their zone. Which they did.

Overall, it went very smoothly though our twenty something project manager nearly went insane. He hates me now, but it was good for him.

emtprt wrote:We are re-banding our UHF radio system to 12.5khz and are working on a calendar for reprogramming the radios. Due to the number of radios the entire system cannot be completed in one day.

Plan A is to program the portables and mobiles first then rep-rogram the bases/receivers. We realize there will be a audio issue for a few days when talking to dispatch and talkaround can be used at scenes.

Plan B Bases first then mobiles and portables.

Which is the better option?

Mark

We did the conversion in a slightly different fashion.

With hundreds of units to reprogram, I only wanted to program the fleet *once*.

We started off by visiting the radio sites and set the repeater transmit to Narrow 12.5 Khz output and left the input as "wide 20/25 KHz".
We have a mix of Quantar and MTR2000 which allow this kind of setting.

Then we proceeded to reprogram the fleet of subscribers, including control stations. We did note that some HT1250's and CDM1250's needed their narrowband deviation for the CTCSS tones turned up from .30 to .35 Khz dev. Their complaint was that they couldn't key the repeater, which is understandable as the repeater input was now "wide" and their over all deviation was too low to reliably key the repeater. This wouldn't be the case once the inputs to the repeater
were set to narrow.

Once the fleet of subscribers was programmed, we visited the repeater sites and programmed the repeater inputs to narrow band also.

While there is an audio difference between the wide user and narrow user, we kept quiet to the subscribers about this and told them that we were
almost done with programming. I truely believe that if you tell people there is a difference, they will start to complain about it!
For the ones that figured the audio difference out and then complained on their own, we thanked them for their input and told them that we only would have it resolved once the entire fleet was programmed.

B.