Looking to ask the Southern California buffs about LAPD radio equipment. What was exactly used and what mdt was used. Trying to get idea of the setup the LTDs and Caprice had. I know at one point in early 80s they transitioned to uhf from vhf. I recall a link where it was shown to some detail but cannot find it. I'm aware of some setups but looking for accurate pictures of it inside the patrol car and or details so I can research it. Name of radio obviously motorola, mounting antenna type and placements, mdt computer brand. Appreciate any feedback anyone has. Mainly shooting around 1985 area of the common setup of radio and mdt equipment. Also exactly when did the vhf to uhf occur and did supervisors have both bands in the units?
LAPD 1980s equipment
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mikepdx
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this may be of some help:
An Unofficial History of the Los Angeles Police Department's Communications Division
Los Angeles Police Department Communications Division History
The image on that page does show the 1980s-90s MDTs. *They were Digicom MDT-800 models.* The model number is the white lettering just above the 2,3, and 4 on the keyboard, above the officer's left hand.
Just above "Digicom MDT 800" the first three square buttons are marked "Vehicle Data," "Traffic Stop," and "Code 6"
Hope that helps.
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This page is a slightly modernized and improved version of the previously mentioned one: http://www.qsl.net/n6uru/kma367-3.htm
FFPM571
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The radios were UHF MX350's in a convertacom mounted in or under the dashboard and a Unitrol siren
And they called the MX350 radios 'rovers'.
Radio_Lady
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Remote Out of Vehicle Emergency Radios. They still use that acronym to identify individual radios, and specifically when a radio's Emergency Trigger has been activated, the RTO broadcasts "All Units, (Unit No.) ROVER has been activated, (Unit No., Unit No.) come in.”
Radio_Lady
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MDT800
The two rows of 8 buttons above the keyboard are:
STATUS: Clear (available) | Enroute | At Scene Avail | At Scene Unavail | Out to Station | (Need) Backup | Assistance | Help (darker button, actually bright orange)
FUNCTION: Vehicle Check | Traffic Stop | Code 6 | W/W (Wants/Warrants) Check | Follow-Up | Request | Dispo | Transmit (entered message)
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Another copy of the same MDT800 picture, if it fits here.
The two rows of 8 buttons above the keyboard are:
STATUS: Clear (available) | Enroute | At Scene Avail | At Scene Unavail | Out to Station | (Need) Backup | Assistance | Help (darker button, actually bright orange)
FUNCTION: Vehicle Check | Traffic Stop | Code 6 | W/W (Wants/Warrants) Check | Follow-Up | Request | Dispo | Transmit (entered message)
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Thanks. So the mobile radio was the mx 350 in a convertacomm setup by sounds of it more then one that was all cabled together to the mdt and head? Did the mdt share the uhf antenna? I also found out that these mdt systems at time were said to be secured but later in 90s if one had proper know how and skill could decode the terminal data which many continued to use that interface binary in LE some up to 2000. Interesting.
FFPM571
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the MDT and MX were separate
Correct, FFPM571. The MDTs and the MX350s/Convertcoms operated completely independent of each other.
The MX350s were strictly 8-channel UHF analog in the 506-507 mHz range. From their start in the early 80s until some time around 1990 or so, the MDTs used the former patrol VHF radios on the five former voice dispatch frequency pairs (A) 159.15, (B) 158.91, (C) 159.18, (D) 159.03, and (E) 158.865 for downlink, and the uplinks were 155.37, 155.58, 155.52, 155.07 and 155.01.
The MDT antennas were, in most cases, trunk-mounted VHF quarter-waves, and the MX350s used roof-mounted UHF antennas of several types.
By 1995-96 when the MX350s started being replaced by Astro Saber IIIs, LAPD had also gained access to UHF-T Channel 16, 482-487 mHz, which paved the way for narrowbanding and, on June 18 2001, going to digital for voice.
At some point c1990, the MDT pairs were switched to either 900 or 800 mHz, and as far as I know they're on 800mHz today.
W6XPA
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Astro Convertacoms
There were just convertacoms in the vehicles. There was no mobile radio. Many plain vehicles had just the convertacom by itself. But most of the Black and whites had the antenna on the car and the bigger microphone in the car hooked up to the convertacom so you could have the benefits of a mobile radio. when in the car. There was a round lock on the convertacoms that would pop out of the front when you put the radio in. Nobody ever had the keys though so they were just left unlocked all the time. So then usually you press the lock back in and the radio moves forward and then most people would grab the radio by it's antenna. I was always just waiting to hear about broken antenna mounts but the radios seemed to take that abuse just fine.
There were just convertacoms in the vehicles. There was no mobile radio. Many plain vehicles had just the convertacom by itself. But most of the Black and whites had the antenna on the car and the bigger microphone in the car hooked up to the convertacom so you could have the benefits of a mobile radio. when in the car. There was a round lock on the convertacoms that would pop out of the front when you put the radio in. Nobody ever had the keys though so they were just left unlocked all the time. So then usually you press the lock back in and the radio moves forward and then most people would grab the radio by it's antenna. I was always just waiting to hear about broken antenna mounts but the radios seemed to take that abuse just fine.
There was no real operational change vis-à-vis radios and MDTs with the arrival of the Saber IIIs, if that's what you're asking. I believe LAPD's Saber IIIs TX defaulted to 2-watts except on the Emergency Trigger frequency (507.2625) which was set to 4 watts. And the Sabers had capability for 256-channels, narrowbanding and analog/digital. And the MX350s' Convertacoms had to be replaced by Astro Saber Vehicular Adapters. These portables were still the ONLY voice radios they had since completing the move to UHF in July, 1982. Only with the next generation of radios did they finally return to "real" mobile radios in 2007-2008, with Motorola (of course) XTL5000s in the cars and XTS5000 portables, still on UHF conventional digital.
Sometime around the turn of the century LAPD got new Motorola MW-520 MDTs, using Windows instead of DOS, and beginning in 2005 replaced them with Dell "workstations" to be compatible with the new and VERY-late arriving Motorola Premier Computer Assisted Dispatch system. They had been limping along with their original many-times patched and re-patched custom designed System Development Corporation CAD ever since 1983.
That's the latest series of radios and MDC's that I'm aware of, but looking at the calendar I can't guarantee one or both of those components haven't been, or aren't ready to be replaced. Just about all of my radio-savvy contacts at the department have retired and/or passed away and left it to a new generation of kids.
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