Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site brl-tgr.ARPA Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!mtuxo!mtunh!mtung!mtunf!ariel!vax135!cornell!uw-beaver!tektronix!hplabs!pesnta!greipa!decwrl!decvax!genrad!panda!talcott!harvard!seismo!brl-tgr!ron From: ron@brl-tgr.ARPA (Ron Natalie) Newsgroups: net.ham-radio Subject: Re: Commercial FM "tweedle" Message-ID: <11380@brl-tgr.ARPA> Date: Thu, 4-Jul-85 20:30:04 EDT Article-I.D.: brl-tgr.11380 Posted: Thu Jul 4 20:30:04 1985 Date-Received: Thu, 11-Jul-85 05:41:29 EDT References: <85@biomed.UUCP> Organization: Ballistic Research Lab Lines: 15 > > Living around Boston, I have heard several walkie-talkies that the > transit police carry and also the EMS ambulance people. They all seem to be > Motorolas. Anyway, it seems that when the base station releases its mike > key, a couple of single tones are transmitted, very rapidly, one after > another, each about 100mS long, with no space in between them, the first > tone higher in freq than the other. One is about 1.5kHz and the other a bit > lower, maybe around 1kHz. WHAT are these for? > Baltimore City has the{k bleedles. They are a data burst. They transmit call information to the stations and engines. The officer in the engine just pushes the buttons to indicate the situation on arrival at the scene. I think the trade name is something like MODAC. -Ron