Prep Radio Malfunctions

[110]

Looking for information on hand held radio systems. My department is currently having trouble with ours

[Niteshift]

Some may disagree here, but after having worked with a couple of different radio systems, I say that Motorola is the only choice. My current dept. still hase some radios in use from Uniden. You can hear the difference in both transmission and reception. The distance difference and ability to transmit from inside buildings is noght and day. I've also had the "opportunity" to use GE and RCA.....they sucked.

My brother is on an Ericson system, they're replacing it with Motorola.

[110]

thx Niteshift. Do you know how many repeater towers and bounce towers your system has. We have older motorola preps but are still having major problems. My city is 36 square miles, we have 1 repeater and 4 bounce towers. How many are required?

[R.White]

110-Regarding your radio system, you did not say what frequency range your present system operates in; some are better than others. Also, did the system ever work well or has it deteriorated just within the past couple of months or years? Another potential problem area in your present system is the method by which the signal from your remote satellite receivers is brought back in...is it microwave or phone lines? If its phone lines, the phone company may be the problem because they are notorious for either messing with the quality of line signals or other improper maintenance, all of which can deteriorate the radio signals your system handles. Chances are that if the system once worked well, then your current problems are maintenance related. Given the size of your jurisdiction, adequate radio coverage should not be a problem, especially if you have a repeater and 4 satellite receivers. What is the age of your existing system? A general rule of thumb is that base station equipment should be replaced every 10 years but many are twice that age and, if properly maintained, still work well. Finally, what is the training and background of your maintenance tech's? Like many other professions today, the standards have been watered down and the FCC doesn't even bother to license most radio tech's today. Many out there haven't got the slightest idea of what they are doing. If your tech doesn't know what he or she is doing, the consequences are obvious. Consider all these things befor scrapping the old system. We have one of those new supposedly super-dooper countywide 800 MHz trunked systems (GE) and after 3 years expereince with it, I'd love to have our old repeated VHF-high band system back! For what its worth! RW

[Irish]

When I first started we were on the VHF system and had a lot of "dead" spots, especially in low areas by the river. We went to the 800 band about 10 years ago. We were told that it would eliminate the "dead" spots. What a crock that was. Places we had no problems with the VHF are now new "dead" spots. Next month we're changing frequencies and joining the SO on their trunk line.

We've always used Motorola. When they work, they're great. When they don't work, they turn into another non-leathal weapon.

[Niteshift]

I'm not expert, so the tower question is out of my league. I only know what I have used that worked and what didn't. Our county is in the (costly) process of going to the 800mhz, so is our highway patrol. Damn, they're expensive. I was never involved in the purchasing process before, but now I understand why my old dept. got so mad when we fried out 2 800mhz radios doing a dog track through a mangrove swamp http://www.officer.com/ubb/redface.gif

[110]

thx for replys. I unfortunately have been thrown into this position by my union. I have a meeting w/ chief on 04/19 about radios and need to cram before then. Any and all ideas and areas I can research on my own are appreciated. Almost lost an officer by lack of communication. Need to take care of this now. Also within next year we will be countywide 800Mhz. Need info on what causes dead spots with that. Thx again.

[Irish]

I don't know a whole lot about the causes of the dead spots. I heard once that it was due to the repeater location. Ours is at the highest point in our area (which is only about 500' above sea level) but it has problems reaching past hills and into vallies. It sort of operates the same way a cell-phone does when you go into vallies or around tall hills and mountains. Not sure, but probably to eliminate this you would need to place relays around the trouble areas. And from what I hear, that ain't cheap. Good luck, 110.

[JKT]

This is a pet peeve of mine.
VHF High Band and up (150MHZ up, including 800MHZ) is line-of-sight; meaning if you can't "see" the tower site, you can't talk to it. This is what causes dead spots. The best system (if there is one) includes several receivers with (preferably) radio or microwave links. The hight of the antenna also plays a major role (the higher the better). This type of system is not inexpensive, but is cheaper than the newer trunked systems. Any well-maintained system will work for a very long time. As an example that it can work; an amateur (ham)repeater in my area that is located 400 feet up on a tower southeast of town. It has a reliable coverage (with a 1.5 watt handheld) of 7 to 10 miles from the tower. A full power (35-50 watts) mobile can routinely get into it solidly from 40 to 50 miles. In this area that covers about 5 counties. It mostly depends on maintenance and the competence (?) of the techs as mentioned above. An ideal system for law enforcement would have one good transmitter site with at least 4 satelite receivers radio-linked to the repeater. Much more reliable than telco lines. (also have emergency power at the transmitter sites). Off my soapbox for now. http://www.officer.com/ubb/biggrin.gif

------------------
Good luck and be safe

Jack

[110]

received an Email from someone who offered help but before I could reply i lost it and the address. New with computer, sorry. Please send again.