296d and edacs monitoring

[jdc50]

I am having a problem monitoring an EDACS system talkgroup. Example a call goes out on the fire department main channel. I put it on hold and when they switch to a TAC frequency I use the thumb wheel to go to that channel. The problem I have encountered is that while I can monitor the Tac frequency I also get the main frequency as well.

What am I doing wrong?


Thanks

 

[ka3jjz]

Jim just from your brief description I'll take a WAG and say it almost sounds like you have a few frequencies that are not programmed correctly. That 'tac frequency' description is much more like something that is part of the system, not separate from it. It's also possible a patch for the main channel is in place to keep everyone informed about what is going on. Hard to say without more information.

Let's start with the basics here - go to the database (see the link in the top blue toolbar?) and supply the URL for the system you are attempting to hear. Take a look at the frequencies listed - they MUST be programmed in the same logical order as shown in the database. If you do indeed want to have simplex tac frequencies, they MUST be in another bank. Unlike a Moto system, you can't mix the two in an EDACS system.

If you are unsure about your programming, your next best step would be to go to the Michigan forum and ask someone, assuming no one answers here (which I kinda doubt).

If you are using software to program your radio, dumping your programming and posting it will help others diagnose your error. There are many good programs for the 296 - ARC250 and ProScan among them.

73 Mike

 

[davidmc36]

If you do indeed want to have simplex tac frequencies, they MUST be in another bank. Unlike a Moto system, you can't mix the two in an EDACS system.

Are you saying that you cannot have conventional frequencies in the same bank as an EDACS Trunk System? I have not seen that in the manual. I indeed do have one bank with an EDACS and some air stuff

 

[fmon]

On a trunking system,
If you use the wheel after hold to go to tac, the frequency doesn't make any difference - thus it could be the same frequency as one first heard the original call on if that frequency was the first available for the tac ID. The talkgroup ID is the change too coms not the frequency.

Edit: LTR trunking may be the exception to above.

 

[ka3jjz]

Are you saying that you cannot have conventional frequencies in the same bank as an EDACS Trunk System? I have not seen that in the manual. I indeed do have one bank with an EDACS and some air stuff

Yes, that's right. The problem lies in the fact that an EDACS system must be programmed in a certain order - when it hits a conventional freq in the same bank, the scanner cannot make the difference between a possible new EDACS channel or something that doesn't belong. Moto systems don't have this issue.

The manual doesn't tell you everything, hi. 73 Mike

 

[davidmc36]

Yes, that's right. The problem lies in the fact that an EDACS system must be programmed in a certain order - when it hits a conventional freq in the same bank, the scanner cannot make the difference between a possible new EDACS channel or something that doesn't belong. Moto systems don't have this issue.

The manual doesn't tell you everything, hi. 73 Mike

So if I tried to put say three of the ten LCN's in a given system, then two conventional, then the rest of the LCN's, I would have a problem. But with MOTO so long as I was programming them as trunk freq's they could be anywhere and intermixed with conventional frequencies? My EDACS bank works OK because I have all the LCN's where they are supposed to be and then a bunch of air stuff.

Would you say the same aspect of the technology that allows you to do CConly on Moto stuff would allow you to intermix the freqs? And the aspect of the technology that requires you to put the LCN's in order is the same aspect that won't allow CConly on EDACS?

 

[fmon]

Yes, that's right. The problem lies in the fact that an EDACS system must be programmed in a certain order - when it hits a conventional freq in the same bank, the scanner cannot make the difference between a possible new EDACS channel or something that doesn't belong. Moto systems don't have this issue.

The manual doesn't tell you everything, hi. 73 Mike

Frequencies in a bank are either in ON for trunking (any trunking) or OFF for anything else whcih could be NFM, WFM, FM or AM. Rule is, don't use conventional freqs in LCN location. This applies to LTR also but Mot doesn't care where the conventional freqs are located.

 

[davidmc36]

Frequencies in a bank are either in ON for trunking (any trunking) or OFF for anything else whcih could be NFM, WFM, FM or AM. Rule is, don't use conventional freqs in LCN location. This applies to LTR also but Mot doesn't care where the conventional freqs are located.

That is something that I never realized. I knew that MOTO stuff did not have to be in exact order but I still was thinking they needed to be all in a group at the start of a bank. I guess it never dawned on me when setting up a couple of banks with the channels of three sites in each, and all the CC's at the beginning with the voice channels following that is basically what I was doing. I set it that way to make more use of space. You just need to L/O the CC's you don't want to use at the time and they are easier to find with the three primarys at the first and the three secondarys next, then all the voice channels. Still not too old to learn!

 

[ka3jjz]

In that case, here's a couple more new concepts for you...

you don't need to lock out CCs in a trunked bank for a Motorola system. The scanner will find the CC; there are more than one because, at certain times (varies by system) the channel where the control data is sent changes. When that happens, the CC will be reacquired by the scanner when you scan the system.

In addition, you can use what is known as control channel only scanning (on Motorola systems only). You need not program every frequency in the system; the scanner will calculate that for you. You only need the primary and alternate control channels. You can then use the rest of that bank for any conventional stuff you want. This wiki article (links are in blue and/or underlined) tells you a bit more about the subject;

http://wiki.radioreference.com/index.php/Control_Channel_Only

73 Mike

 

[fmon]

Also with Mot, only one site per bank will work unless you are roaming (term used in new GRE scanners) and disengage the current CC, it will then acquire and stay with another. Otherwise, the scanner will always stay on the first CC acquired.

I've used above on several RV trips with a 785 mounted above the steering wheel.

BTW, Mot UHF or VHF require all frequencies to be programmed, CC only will not work.

 

[davidmc36]

In that case, here's a couple more new concepts for you...

you don't need to lock out CCs in a trunked bank for a Motorola system. The scanner will find the CC; there are more than one because, at certain times (varies by system) the channel where the control data is sent changes. When that happens, the CC will be reacquired by the scanner when you scan the system.

In addition, you can use what is known as control channel only scanning (on Motorola systems only). You need not program every frequency in the system; the scanner will calculate that for you. You only need the primary and alternate control channels. You can then use the rest of that bank for any conventional stuff you want. This wiki article (links are in blue and/or underlined) tells you a bit more about the subject;

http://wiki.radioreference.com/index.php/Control_Channel_Only

73 Mike

I am doing it with VHF Moto and the 296 won't do CConly. If I set it up with just two sites in each they are distant enough that it will only ever hear one CC at a time and automatically track the site that is in range. But that only gave me 18 sites (I left one bank for an EDACS system) I was trying to do almost all of the sites in my Zone. When trying to get three sites in all the banks there was too much overlap with CC freqs re-used as voice channels on other sites it just worked out better to put neighbouring sites in each bank and lock-unlock CC's as needed. All is cured now for mobile with 996 hard-wired/in-dash in the car and the Magellan 315 hard-mounted as well.