Most, if not all, radios that can handle MDC1200 coding will automatically mute the speaker during the code reception interval. The CPS tutorial clearly explains how this mute interval is adjusted, if necessary.
The volume of the "pre-beep" is adjustable from zero to ear-splitting volume. The CPS tutorial clearly explains how this is adjusted, if necessary. I tend to agree with the consensus, that the radio system in question appears to be poorly designed and poorly executed. Although a trunking system might solve many of the problems, consideration should be given to consolidating some of the non-public-safety radio users (street sweepers, forestry, utility, building inspector, etc.) onto a multiple-PL repeater, a la community repeater, so that public-safety users have a clear channel. A repeater may not even be needed for the lower-tier radio users; if they all have mobile radios, perhaps one or more simplex base stations will work just fine. If the number of such non-critical user groups is small, a single RF channel with different PL tones might be sufficient. 73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of n9wys Sent: Wednesday, August 27, 2008 9:31 AM To: [email protected] Subject: RE: [Repeater-Builder] Re: Trunking Features w/o Trunking? Bob, And I believe that individual radios can be set to MUTE momentarily when PTT is pressed (during MDC transmission) so the user doesn't get a "beep" when their PTT is pressed - this will eliminate your concern for police officers "giving up their positions" etc. Yet you can still have it (PTT beep during MDC) enabled for the dog catchers, etc. Mark - N9WYS -----Original Message----- From: [email protected] <mailto:Repeater-Builder%40yahoogroups.com> On Behalf Of Mike Morris WA6ILQ Sent: Wednesday, August 27, 2008 2:42 AM To: [email protected] <mailto:Repeater-Builder%40yahoogroups.com> Subject: Re: [Repeater-Builder] Re: Trunking Features w/o Trunking? At 09:47 PM 08/26/08, you wrote: >At 8/26/2008 21:14, you wrote: > >Thanks for the reply Eric, > > > >First, it's that dam, loud BEEP when the PTT is pressed and Pre is > >programmed. > >So THAT'S what I hear coming from the FD/PD radios inside the Comm. tent at >the marathon. Yeah it's annoying alright, & I can't even hear what's >coming out of the radios from where I sit. But I sure hear that tone at >the beginning of each transmission. > >If they'd just use 1/2 second or so of audio delay on the TX audio, they >could stick the data burst in front of the audio without losing anything. > >Bob NO6B Bob - listen to Glendora City PD Dispatch on 154.845 - whoever set up that system did a nice job. It's a highband repeater with MDC mute, so the other radios never hear any more than a very slight "tink" at the front of a carrier, yet the MDC data appears on the dispatcher display. MDC is a two-tone AFSK system. Mark and space tones are 1200 Hz and 1800 Hz. The unit ID is limited to 4 digits. More info at <http://en.wikipedia.org/wiki/MDC-1200 <http://en.wikipedia.org/wiki/MDC-1200> > Mike WA6ILQ ------------------------------------ Yahoo! Groups Links
