Question about digital

[Thatsclear]

Was there any digital in use in the 80s and 90s? Was mostly all public safety analog conventional at that time? Thank you!

 

[KevinC]

Was there any digital in use in the 80s and 90s?

Yes.

 

[JethrowJohnson]

*I think* the 70s - 90s were when P25 was just starting to get popular. Maybe 70s is stretching it though. But even then I imagine the departments that did have it were few and far between until this past decade or so.

 

[nd5y]

Was mostly all public safety analog conventional at that time?

It varies by location. Just like it does now.

 

[MTS2000des]

*I think* the 70s - 90s were when P25 was just starting to get popular. Maybe 70s is stretching it though. But even then I imagine the departments that did have it were few and far between until this past decade or so.

P25 turned 30 years, it's began in 1993:

Project 25 Technology Interest Group

Project 25 Technology Interest Group

www.project25.org

Earlier digital voice modulation schemes were used by Motorola (Astro VSELP), Ericcson/GE (ProVoice), and digital voice encryption has been around since 1976 (DES).

 

[KevinC]

P25 turned 30 years, it's began in 1993:

Project 25 Technology Interest Group

Project 25 Technology Interest Group

www.project25.org

Earlier digital voice modulation schemes were used by Motorola (Astro VSELP), Ericcson/GE (ProVoice), and digital voice encryption has been around since 1976 (DES).

Wouldn’t GE be AEGIS?

 

[12dbsinad]

I believe New Hamphire State Police was one of the very early adopters of P25 (conventional) and was sorta a beta tester for Motorola's Astro platform in the beginning. It all stemmed form a long mutli-state chase and interop problems because NH was on Lowband at the time.

 

[MTS2000des]

Wouldn’t GE be AEGIS?

Yep almost forgot. That predated ProVoice, which seemed to come out when the first 4.1 Astro systems appeared offering "P25 voice" on 3600 baud CC.

 

[ladn]

The Los Angeles Police Department (LAPD) was an early P25 adopter. They migrated from a conventional VHF system into a conventional UHF system in the early 80's. They were still conventional UHF FM for the 1984 Olympics and went UHF P25 around 1987.

 

[N4DES]

Yep almost forgot. That predated ProVoice, which seemed to come out when the first 4.1 Astro systems appeared offering "P25 voice" on 3600 baud CC.

We had Astro 3.0 that had P25 voice channels with a 3600 baud CC in 1999, so it was offered even before 4.x.

In addition, the first SLERS in Florida, that was being rolled out by Motorola until it was taken away, was a multi-zone 3.0 system that first used a VSELP vocoder with their 3600 baud CC. Once APCO chose the IMBE as the APCO25 Vocoder standard Motorola re-flashed all of the subscribers and infrastructure to IMBE in the mid 90's.

 

[MTS2000des]

Cleveland Ohio had that same VSELP 3600 baud CC system until a few years ago, they were one of the first, 1993 IIRC. They were running it in VSELP until they transitioned to an M-core system, replaced their subscribers with APXs. They were one of the last Astro Saber users around!

 

[N8IAA]

Cleveland Ohio had that same VSELP 3600 baud CC system until a few years ago, they were one of the first, 1993 IIRC. They were running it in VSELP until they transitioned to an M-core system, replaced their subscribers with APXs. They were one of the last Astro Saber users around!

Remember that well Eric. Lived in Cleveland at that time.
Cleveland PD used 450 MHz until then. Easy to monitor till VSELP. They had problems building it out also.