Control and Alternate Control Channel?

frankcastle · #1 (**permalink**) 06-19-2009, 03:24 PM

Is it necessary to program both the control and alternate control channel? I was in Michigan yesterday. I programmed the area I was traveling to into the 396xt. I only programmed the control channels and left out the alternates. I wasn't picking up nearly as much as I thought I would. When I switched over to ID search instead of ID Scan I picked up a lot more. Keep in mind I programmed all the talk groups listed in RR for the area I was in. Just wondering if you need both for each tower.

Steve73 · #2 (**permalink**) 06-19-2009, 05:06 PM

Yes put them both in. If the primary fails the alternate should kick in. I monitor Indiana Safe-T and have seen the alternate CC in use a couple times.

whacker · #3 (**permalink**) 06-20-2009, 08:23 PM

A strange exception to this is that currently, if you're trying to monitor MPSCS in Berrien, Cass, or Van Buren Counties (when in range), the CC used by the Sumnerville tower is 868.9125, which is listed in the database as just a voice channel.

Being a Michigan resident, and having monitored MPSCS since early 2006, there has really only been a short period (just a couple of months ago) where the CC was NOT 868.9125 at this tower, so that may help you a bit. Don't know what they currently consider the alternate for this CC.

ofd8001 · #4 (**permalink**) 06-20-2009, 11:08 PM

This kinda boils down to a "values" decision. Are you willing to miss something if the primary goes down? If so, then just the primary is what you should program.

Me I program the primary and alternate control channels in the systems I listen to. If it is a system I really want to listen to and want to avoid missing something at all costs, I'll program all the channels. That's just in case they change a voice channel into a control channel because of something weird going on.

I might be wrong on this, but a scanner scanning in the control channel only mode, is only going to respond to control channel data, and pass up whatever voice channels may be active. In other words, say a system has frequencies A, B, C, D and E with C being the control channel. When the scanner is scanning and there's a voice conversation on A, it will skip that and keep scanning until it hears that control channel.

So, you really can't go wrong, other than using up scanner memory by programming all the channels in.

JoeyC · #5 (**permalink**) 06-21-2009, 03:35 AM

You should always program the primary and alternates for the simple fact that occasionally if not for only temporary the system may switch controls and you will not hear anything if your radio is trunking and there is no active control channel being monitored by the radio.

ofd8001 you are wrong in your assessment. A scanner properly trunking a system in control only mode is all that is necessary. The scanner doesn't scan freqs A, B, C, D and E. It listens on C only and depending on whether your scanner is set to pick up all TGs (search or open) vs. only those you program in (scan or closed) will the A, B, D and E become relevent to your listening.

The only benefit for programming all system freqs in is if you need to attenuate one or more of the voice channels (but not all) because of intermod or interference, or perhaps for usage during failsafe mode, (although I think it probably would require the channels be programmed as conventional and wouldn't work if the system were programmed properly as a trunked system.)

GTO_04 · #6 (**permalink**) 06-21-2009, 01:14 PM

Quote:

Originally Posted by JoeyC

You should always program the primary and alternates for the simple fact that occasionally if not for only temporary the system may switch controls and you will not hear anything if your radio is trunking and there is no active control channel being monitored by the radio.

ofd8001 you are wrong in your assessment. A scanner properly trunking a system in control only mode is all that is necessary. The scanner doesn't scan freqs A, B, C, D and E. It listens on C only and depending on whether your scanner is set to pick up all TGs (search or open) vs. only those you program in (scan or closed) will the A, B, D and E become relevent to your listening.

The only benefit for programming all system freqs in is if you need to attenuate one or more of the voice channels (but not all) because of intermod or interference, or perhaps for usage during failsafe mode, (although I think it probably would require the channels be programmed as conventional and wouldn't work if the system were programmed properly as a trunked system.)

Is there any harm in having the voice channels programmed in, other than taking up memory? That way in the event of a voice channel would be used as a CC for whatever reason, they would be covered. That seems to be rare, but there are some reports of it happening.

GTO_04

JoeyC · #7 (**permalink**) 06-21-2009, 02:04 PM

I thought that a system could only have a maximum of 4, but I am no expert. I know on the 3 systems I monitor, the controls have never changed from the published freqs in the 10 or so years I've monitored them.

whacker · #8 (**permalink**) 06-21-2009, 07:58 PM

If all else fails, and you aren't receiving a CC when you think you've got all the necessary stuff programmed in, just do a Search in the applicable freq. range, in this case 856 to 869 MHz or thereabouts (I have one of my Custom Scans set up for just this purpose). If you're in range of any control channels (of any/all trunking systems), the scanner will stop on something active, and after a while it'll show what the system is on the display. If you can ID what you want, program that freq. in manually, and away you go (don't be afraid to manually program/select stuff - unlike some people). At least this has worked for me with MPSCS, Safe-T in Indiana, and the city of Mishwaka. You can't always count on published accounts in the Data Base.

frankcastle · #9 (**permalink**) 06-22-2009, 09:17 PM

Thanks for all the replies. Here is another question for you experts. 95% of everything I scan is SAFE-T. Would it be a problem in any way to program all of Indiana's SAFE-T control channels and alternates in every SAFE-T system I monitor. That way as I travel throughout the state, as long as I have some TG's programmed for that area, I'll pick it up because I'll have the control and alternate channel. It seems that on the 396XT it finds the local tower and locks on it as the control tower. Am I right about this? If that is the case, it shouldn't slow down the scanner because it's not searching all the control channels unless I travel to a different area. Does this make sense or is there better way to be sure to catch the action as I move through the state? Thanks!