Dearborn, MI Upgrades Radio Equipment

[MetalManMI]

http://www.detnews.com/2005/wayne/05...B02-304256.htm

Council updates radio base stations

The City Council approved the purchase of radio base stations, key components of the radio communications system used by police, fire and EMS personnel. The current equipment, purchased in 1987, is outdated; the new equipment will cost $93,000, according to city officials.

[SEMTTP]

I wonder if this will be new equipment for their existing system or if they will upgrade to the Western Wayne TRS???

Eric

[Thunderbolt]

This will be for their existing VHF and UHF systems. With the current Motorola equipment in place, they received 18 years of great service out of the base transmitters. The prior system they had was from General Electric, using Mastr Pro and Mastr I base transmitters. That system was first put into service in 1967, when the Dearborn Police completely moved off VHF-Low band.

Prior to 1966, the Dearborn Police started out on 45.08 MHz, after W.W. II, under KAR-444, which was handed over to the DPW, when they purchased a newer system in 1957 that was made by RCA Victor I believe, and used 45.14 MHz as their new Dispatch channel. However, skip was really bad and they decided to move to VHF-High band to eliminate interference in the mid-1960s.

73's

Ron

[Combustion]

Dearborn has never had a problem getting their signal to propagate until recently. In the past I have been able to recieve them very well as far away as Waterville Ohio with a roof mounted antenna on my vehicle. Right now I have a very hard time recieving them at my home which is only about 20 miles from their transmitter location (that may be another issue, what was good scanning in the past at my home appears to be a radio signal black hole now, as many agencies that I could scan in the past are barely audible now). When my friend worked for Dearborn in the 1970's there was no problem for the cars to hit the repeater from 40 or more miles outside the city. The apparently have selected repeater locations that have the appropriate elevation to be very effective. I wouldn't move away from a system that works that well. I believe they will use their current system for many more years. Dearborn also seems to be staffed well enough that land line or intercity radio info from other agencies gets routed promptly and accurately to the appropriate mobile units.

[MetalManMI]

They made some recent changes (within the last week or so). Now the mobile and/or portable radios have a coded data burst when they unkey...they never had that before...it used to be a very subtle chirp when they unkeyed...almost inaudible...

[Thunderbolt]

I just chatted over the phone with a tech I know that works for Motorola, and he said although Dearborn PD will buy new conventional radios, they will move up to the MPSCS within the next 1-3 years. Of course this depends on the availability of funding to procure the new radios. Likewise, they will be joining the rest of the county when they make the switchover to the MPSCS. However, no firm date has been set for all as of this to happen.

The Dearborn PD 158.805 MHz system, use to be very high profile, and under the old G.E. specs I believe they used 5/8 wave antennas on their patrol cars. However, they use to licensed for an ERP of 350 watts, and I think the last time they renewed their radio license the power was dropped either by the FCC or the radio techs.

73's

Ron

[Combustion]

I don't want to go off topic too much, but the ERP reduction may explain why several agencies have become harder to recieve in recent years. In the past 3-5 years almost all of the VHF users seem to not be as effective (easy to pickup) as they were in the past.

Is it possible there is an initiative or policy to lower the general stength of RF emissions?

[Thunderbolt]

Originally Posted by Combustion

I don't want to go off topic too much, but the ERP reduction may explain why several agencies have become harder to recieve in recent years. In the past 3-5 years almost all of the VHF users seem to not be as effective (easy to pickup) as they were in the past.

Is it possible there is an initiative or policy to lower the general stength of RF emissions?

I believe its part of the upcoming narrowbanding project on the VHF and UHF bands in the USA, and eventually Canada. The idea is to split the spectrum in such a way that available bandspace will be doubled. This was supposed to have originally taken effect this year, but was pushed back several years because many agencies complained they didn't have sufficient monetary capital to run out and buy new equipment.

73's

Ron