A Piece of History

[DiGiTaLD]

Those of us who have been in the communications or public safety fields and/or scanning hobby for a while will appreciate this. I bring to you, from parts unknown, a full color scan of a vintage Indiana Hospital Emergency Radio Network (IHERN) Operations Manual.

Link: 1973 IHERN Manual

In the 1970s the IHERN covered the whole state on simplex analog VHF FM and did it all over-the-air, no wirelines involved, and regular old PL tone to handle selective calling functions. Granted, there was no real-time audio path from Angola to Evansville, but if the operators at each facility followed the procedures in the manual, passing a message all that way would have been possible.

Sadly, VHF IHERN has been relegated to an "outdated" legacy system, a mere shadow of it's former self. The old MICOR and MASTR solid-state rock radios that put this thing on the air back in the day are rapidly being replaced by narrowband compliant modern microprocessor controlled gear, like the MTR 2000 and MTR 3000, at least at the facilities that choose to keep it alive as a secondary mutual aid and pre-arrival option. At most facilities nowadays, its a secondary, if not a tertiary option behind local and regional 800 MHz trunked options.

 

[Anon6083]

A fun document to skim through, thanks for sharing. I particularly enjoyed the documentation regarding the base transceiver units.

 

[W9NES]

Wishard Hospital KRZ949 used to do a morning and a evening test on 155.340 two times a day back in the 1980's. Wishard would call all the surrounding hospitals two times a day to make sure the network was working. 155.340 IHERN is still in use today aross the state. I also hear 155.340 used everyday talking to lifeline and other medical helicopters thru a link. 155.340 is used on a daily use for out of town ambulances and medics doing transports to central indiana hospitals. 155.280 is still being used as I have heard radio traffic on 155.280 before any major event in the metro Indianapolis area. Wishard Hospital used to have a base station like the one pictured in the manual at The Indianapolis Red Cross at 441 East 10 Street in Indianapolis.This was in the Emergency Operations Center in the basement along with Marion County Sheriff, Indianapolis Police Department(IPD) IFD, Marion County Rural Fire along with Indianapolis Power and light and Citizens Gas and Indiana Bell Telephone Company.