Scanning MARCS Sites Using Only Control Frequencies

[WeldGuy]

When I first bought my 436 and entered the world of digital, I had help setting up my favorite sites to monitor. Somehow, he set up my 436 using Sentinel so that I only needed to enter the Control Frequencies (Primary and Secondary) for each site, NOT all the talk frequencies. Somehow it found the talk frequencies on its own. The Service Type is Custom 1.

Now the problem... I'm adding a new MARCS site in my area. I edited an existing site by changing the Site ID info and changed the two Control Frequencies. Now I hear NOTHING for that site unless I include all the talk frequencies too. What am I doing wrong???

 

[ofd8001]

Nothing. It is possible that the information you got was wrong. There was a different control channel frequency, which happened to be a voice frequency. When you programmed the voice frequencies, you "picked up" the correct control channel.

If you look back on previous threads, you will see a lot of discussion on whether to program only listed control channel frequencies or all frequencies (listed control channel frequencies plus voice frequencies). Some folks believe in only listed control channels frequencies and that usually does the job. Then there are the more enlightened of us say program them all.

You have just proved our point why all should be programmed. Database mistakes are rare, but there is the human component and a wrong frequency is identified as a control channel, or what is thought to be "just a voice frequency" happens to be a control frequency.

(Going to the correct voice frequency when a channel grant is made, is part of the scanner's "magic".)

Programming all frequencies associated with a site will not slow scanning if you only scan sites within reception range. There is ample memory space, even for large statewide systems, that programming all frequencies will not overfill the memory bucket.

 

[jonwienke]

Systems also swap control channels on occasion, without notice. If you only program listed control channels you're susceptible to losing a site at any time. Programming all the channels slows down scanning slightly, but not enough to notice without a stopwatch.