Help with frequency order

[kingpin]

If there any rhyme or reason to the channel order on EDACs systems? It just looks like random frequencies to me in a certain order. Mobile County just added 10 more frequencies to their Springhill tower and while I knew the order of the first 10, is there any way to find out the logic order with the new frequencies?

Jason
KE4KZY

 

[INDY72]

Good question... some EDACS are in LCN by ascending order,...others are in LCN by descending,.. still others are just at the whim of the system designers.. I also would like to know if there is a simple way to get the proper LCN figured out. I know of one system that started out with 5 freqs and they were easy to get the LCN's but now there are nearly 20 freq's and its gonna be tricky getting the new LCN's.

 

[INDY72]

Additionally: Is there a freeware software out there that will place an EDACS system into proper LCN????

 

[Pro-95]

The LCN of a system is purely whatever the SA wants it to be. This freedom IMHO adds to potential problems down the road with additional nearby sites or in the case of Nevada with it's statewide system makes for many banks of randomly selected LCN's in a scanner application. Not that the SA or whomever designs their system with scanning in mind but using a common or standard LCN allocation would just make it so that one less thing for them to worry about. Additonally from what I gather each radio must be hardcoded to some extent and in the appilcation of many multiple sites why a standard grouping of LCN's isn't used with growth in mind as well as ease of implementation I will never know.

Not to mention that if some sort of standard is acheived and you license a handfull of freq's you could make groups of "X" freq's in the order of ABC, then build on that for supergroups of ABCDEF as an example. This would significantly reduce the overall amount of frequencies a licensecee needs to cover a huge wide area with many smaller sites and a couple of super sites. In the case of a statewide system you could reduce the costs of licensing as well as hard-programing and maintaining the field radios. Oh well this rant is over....

Onto finding the LCN's. I read somewhere the process of finding the LCN but it requires two scanners and one doesn't need to be a trunktracker but a simple 800Mhz scanner will work. It involves listening to one channel while trunktracking on the other scanner. I'll see if I can find the instructions.......

 

[loumaag]

As Mike said, there is no logic to LCN assignement. It is at the whim of the system admin. Now what I don't understand is the feeling expressed that there should be logic applied. I mean the real radios don't care, they are programed to know what sites use what channels in what LCN. There is never an interference problem (other than adjacent frequency interference).

I mean if site a uses a line up of 1, 2, 3, 4, 5. There is no reason why the next site over doesn't use the same lineup (with different frequencies of course). The best of all worlds (from a scanner perspective) is a simulcast system. All channels the same, in the same LCN, at all the sites; what could be better.

 

[Pro-95]

Now what I don't understand is the feeling expressed that there should be logic applied. <snip> There is never an interference problem (other than adjacent frequency interference). <snip> The best of all worlds (from a scanner perspective) is a simulcast system. All channels the same, in the same LCN, at all the sites; what could be better.

Sorry I prefer logic and standards, live long and prosper. Seriously though why not have a standard? I mean when I used to design networks (computer and microwave broadcast) in applications from small office to 900+ users I always used the same schemes for all facetes of the network. From cable layout, punch down block locations and cable and node labeling, outlet labeling, user levels and security. In the microwave rebroadcast arena I always used the same node id for each channel and channel group kept the transmitters in the logical order of channel number order. Even channel groups even though they were different channels in a group the logical progression of programming tiers always had the same number scheme. It really made for a much easier administration and support since no matter what client called I knew their system with the only change being that of the extent and size.

Could you imagine if in a computer network there was several different orders of cable pair orders. I mean sure it would work and the computers wouldn't know the difference, but what a nightmare to have to remember or re-evaluate each cable connection.

 

[loumaag]

...It really made for a much easier administration and support since no matter what client called I knew their system with the only change being that of the extent and size. ...

Mike,
I don't disagree with there being a standard. I mean order and logic right? :lol:

Of course, your standard might be different from my standard. If I came in behind you (at one of your computer network installs) I might not like the way you organized things. I might have my own way of doing things. Just because you don't see the logic behind some system, doen't mean there isn't a logic behind it.

Now, having said that, consider this; suppose the logic behind the setup has nothing to do with real logic. Suppose it is only so that only the current guy in charge understands it. Suppose he is a guy who isn't too bright but just cany enough to place some insurance against being replaced easily. :shock:
This too is a form of logic. :lol:

 

[Pro-95]

This too is a form of logic. :lol:

Don't remind me. I've seen this logic applied way to much in the past.

Yep I agree your logic and my logic may not be the same, so I see your point.

And I'll admit that my understanding of the systems from the SA point of view is extremly limited so I'll refrain from interjecting until my knowledge base improves.

 

[emtLarmy15]

If you search the forums, you can find out how to decode the LCN...

I have done it before. It is easiest with 2 scanners.

In a nut shell one watches the control channel to see what ID is assigned to what channel.....I know when I did it, It was pretty easy, cause I cheated a little bit and used a radio from the system, which is assigned to me.

All I did was put it on our Company Talkgroup, and just key the radio, saw on the control channel which LCN number my t/g had been assigned, and then on the second scanner, I looked at the Freq and saw it which freq was active with me doing the test on it.

As long as you know the t/g ID's its not hard.

Chris