Thoughts on our communications system

Due to heightened sensitivity of the issues surrounding the paging system I am hearing reports of strange things occurring on folks pagers. Things such as one department being toned and a pager from another department opening up but not hearing any voice, pagers opening up when no one is being toned etc.. Many of these occurrences are not new and have been happening to some degree over the years and I would like to say a few things about that.

First, the Minitor V is a very sensitive device and has a history of opening up on “close” tones. Many of the departments in Lapeer County have tone sets that are very close to one another and on occasion will open up when it thinks it hears its own tone. A few years ago Motorola issued a software update to help control sensitivity of the device. If you think you have a pager that is still too sensitive you can bring it in and I can further adjust the sensitivity of it.

There is also the likelihood that there could be some other transmitting device in a frequency band near our assigned frequency that could be transmitting at high power and causing bleed over into our band and causing a pager to open up. As an example, I’ve had it happen before on my car stereo while listening to the radio that a person on CB with a linear amplifier (which is illegal to use) was pushing so much power on the citizens band that his transmission bled over the FM radio band and blasted me in my car right over the radio station.

Secondly, there are areas of the county that traditionally have poor coverage even though they are in relative close proximity of a tower. The likely cause for this is what is called “dead zones” in radio wave propagation combined with terrain features. This also accounts for why people will be well outside of the county and get a page and have it be crystal clear.

Thirdly, for some who keep their pager on an “open” status, on occasion you hear bursts of data. Those are a couple of different things. One kind is the alpha-numeric pages that Lapeer County EMS uses and formerly some MFR groups. Also the system itself sends out data bursts periodically to “poll” the sites. The system polls the sites to make sure they are either still online, offline or to find out if there is something going wrong that it needs to send out an alarm about.

Degraded Communications

 

There are just so many variables to look at in wireless communications from terrain features, vegetation, local weather conditions, space weather (i.e. solar flares, sun spots), buildings, orientation of the pager, where it is worn on the body, body type, direction the pager (or radio) is facing relative to the source signal, heavy machinery, high tension power lines, electronics and so on. All of these things and more play a role in how radio communications work, or don’t work for that matter. I think that many times, these weird things that happen are not always due to a problem with the system, but can be attributed to external factors interfering with our system.

Also important is the age of our system as we are all very aware of. Blumerich and I keep a very close eye on the system and we check it and test it weekly to make sure it is operating within specification. Even though when it is operating normally, there can still be issues with receiving pages that just cannot be explained other than looking at some of the other variables I mentioned already.

Regardless of all that, the looming age of the system is a big concern and every time we experience a problem with it, it further highlights the need to have it replaced with a new system and more towers installed to increase coverage in the deficient areas. Please continue to keep your ears tuned to any potential problems and let us know about them.