[BC] TIS Transmitters...

[Burt I. Weiner]

The LPB transmitters will easily run 125% positive peaks and that's 
legal for the TIS/HAR service.  There is a requirement that the audio 
bandpass be limited to 3 kHz.  On two that I maintain I'm using Orban 
9100B processors and Inovonics Modulation Monitors.  I've removed the 
OpAmp Labs limiter module from the transmitters but leave the 3 kHz 
Low Pass filter in place.  There's no reason why they can't sound as 
good as one of Clear-Channel's AM's.

Many TIS/HAR installation will use telephone calls to feed audio to 
the message recorder.  I remember once hearing one where it sounded 
like they simply meant to hang up the phone, dropped it on the floor, 
picked it back up and then hung it up.  Quite often Cal-Trans and 
other entities will place them too close together on the same 
frequency with horrible overlap causing severe beating and audio 
overlapping between them.

Burt

>From: Douglas Pritchett <radiofool at gmail.com>
>
>Alan, most transmitters made for that service are purposely limited in
>modulation (50%?) and freq response (3kc?). Why? So that pirates won't
>use them to do their dastardly deeds. There is supposedly some FCC
>rule which, of course, I can't recall.
>
>Regards....
>Douglas B. Pritchett
>radiofool at gmail.com