CTCSS Setting(s)

[guadmaster]

I recently installed an outside antenna and I've now started picking up more communications (that's the good part), the problem is that I'm getting two different Sheriff Departments on the same frequency but with different CTCSS id's. I went into the “Set CTCSS/DCS” area to see if I could change the settings to separate these two id's and soon came upon my dilemma. The question is, how do I set, or can I change the setting to separate them?

BCD396T
155.70000MHz
C131.8 Webb County Sheriff
C186.2 Demmitt or Duval County Sheriff

 

[crashcrew]

I recently installed an outside antenna and I've now started picking up more communications (that's the good part), the problem is that I'm getting two different Sheriff Departments on the same frequency but with different CTCSS id's. I went into the “Set CTCSS/DCS” area to see if I could change the settings to separate these two id's and soon came upon my dilemma. The question is, how do I set, or can I change the setting to separate them?

BCD396T
155.70000MHz
C131.8 Webb County Sheriff
C186.2 Demmitt or Duval County Sheriff

Just make them separate channels....one for Webb County and one for Demmitt or Duval. That's the simplest thing.

Example:
Channel "1" Webb County Sheriff
155.7000 PL 131.8

Channel "2" Demmitt County Sheriff
155.7000 PL 186.2

 

[garys]

Do you want to listen to both, but just know which is which. Or do you only want to listen to one?

If you want to listen to both, just enter the frequency into two memory slots and then put each PL and Alpha Tag in. If you only want to listen to one, then enter the frequency once along with the PL and Alpha Tag.

If you are using ARC396, the listing should look something like this,

155.700 Webb Sheriff 131.8
155.700 Duval Sheriff 186.2


Gary

 

[Don_Burke]

I have a similar situation here with four tunnels using the same frequency with different tones.

The problem with using different channels on the same antenna is that the strongest outfit will block out all the others. I find myself losing the information on a major accident while someone discusses how they really ought to get the grates repainted.

They can not hear each other and do not interfere with each other as near as I can tell.

The only solution I can think of is to use several directional antennas each feeding one scanner. I have the parts, it is just a matter of getting the time.

 

[kb2vxa]

Hi all,

"The problem with using different channels on the same antenna is that the strongest outfit will block out all the others."

Well that makes sense PL or no PL. The difference is without PL you'll hear the override, with it the channel falls silent. In this situation I'd prefer an open channel so I could hear what's going on and not wonder why the channel went dead and scanning resumed.

Skip propagation also causes this problem and if it's strong enough it'll knock out the radio system leaving users wondering why they suddenly lost the signal, they don't hear the other station. Yup, I've heard a few confused dispatchers wondering "Is anybody out there?" like that guy Pink Floyd.

 

[Don_Burke]

Hi all,

"The problem with using different channels on the same antenna is that the strongest outfit will block out all the others."

Well that makes sense PL or no PL. The difference is without PL you'll hear the override, with it the channel falls silent. In this situation I'd prefer an open channel so I could hear what's going on and not wonder why the channel went dead and scanning resumed.

Skip propagation also causes this problem and if it's strong enough it'll knock out the radio system leaving users wondering why they suddenly lost the signal, they don't hear the other station. Yup, I've heard a few confused dispatchers wondering "Is anybody out there?" like that guy Pink Floyd.

No skip involved here. These tunnels are only a few miles apart. They are all on 453.85 using tones of 100.0, 127.3, 156.9, with the loud one on 192.8.

I do not wonder why the channel went dead since the scanner stops on the other tunnel's signal. The open channel idea is okay if you are strapped for channels. There is no such problem here. Having a channel for each tunnel at least lets me use the alpha identification feature.

I _do_ get a bit frustrated, so the antenna assortment will be going up pretty soon. At first it will be all corner reflector UHF TV antennas. I suspect I may have to go to loops to get the job done if indeed it can be done at all from this location.

 

[kc4jgc]

The only solution I can think of is to use several directional antennas each feeding one scanner.

---- The following may be starting to veer off topic; being more local oriented between Don and I ........

Don, I'm not sure that will accomplish what you want. If I understand you correctly, you want to point a UHF TV antenna ( 4 in all ) to each of the tunnels, going into a 5 way (is there such a thing?) splitter with the common going into your scanner in the office. At the scanner, you have 453.85 programmed in 4 separate channels with the appropriate CTCSS for each tunnel. You're hoping that the setup will decrease your QRM from the Downtown Tunnel while listening to activity at another tunnel.

You may be able to use one for 2 of the tunnels (Downtown & Midtown) since they're in the same general direction (I think your office is in Va Beach somewhere maybe Kempsville?). Then one each for Monitor - Merrimac and Hampton Roads. What I'm trying to get my brain around is to how they will help with your reception of all four facilities. I'm thinking that having all those antennae will make the problem worse. My thinking is to have only one pointed to an area about halfway between the HRBT and MMMBT, leaving the Downtown and Midtown off to the side. It's worth trying. I'm still thinking that Downtown is still going to give you trouble with capturing your reciever no matter how many directional antennae, no matter what the azimuth of one antenna.

I could be wrong. Again, it's worth trying. I'd be interested in hearing of the results of your new setup after you get it installed.

 

[Don_Burke]

---- The following may be starting to veer off topic; being more local oriented between Don and I ........

Don, I'm not sure that will accomplish what you want. If I understand you correctly, you want to point a UHF TV antenna ( 4 in all ) to each of the tunnels, going into a 5 way (is there such a thing?) splitter with the common going into your scanner in the office. At the scanner, you have 453.85 programmed in 4 separate channels with the appropriate CTCSS for each tunnel. You're hoping that the setup will decrease your QRM from the Downtown Tunnel while listening to activity at another tunnel.

That will not do it. There will have to be seperate downleads from each antenna feeding a scanner. I need to reduce the signal level of the undesired tunnels enough so that the capture effect will let each scanner only hear the tunnel it is assigned to.

I'm still thinking that Downtown is still going to give you trouble with capturing your reciever no matter how many directional antennae, no matter what the azimuth of one antenna.

I could be wrong. Again, it's worth trying. I'd be interested in hearing of the results of your new setup after you get it installed.

I expect I will be going to loops to get tight enough notches in the pattern. I also expect I will not be able to get all four tunnels to be independent without radical measures like putting a remote receiver at one of the transmitter sites.

I am initially going to try this from the house, but do not expect much as the azimuths are pretty close.

BTW, I no longer work for Metro. On the morning of 02 November I had a blowup with corporate and gave two weeks notice. They told me to leave at lunch. The next morning I was hired by Sinclair. The hours are better and the parking is better. I have four transmitter sites to go to (that might become five soon), so it is never the same old grind.

There is a difference in pay, but I will figure out some way to spend the extra money.

 

[mcema699]

Quick question, have you attenuated the tunnel freq/PL with the strongest signal. Just a thought, I have no practical reference.

 

[kc4jgc]

BTW, I no longer work for Metro. ............. The next morning I was hired by Sinclair. The hours are better and the parking is better. I have four transmitter sites to go to (that might become five soon), so it is never the same old grind.

WOW! I hadn't realized that (or if I had I forgot ). Obviously if you're at Sinclair there's no way you can attenuate Downtown since you're probably looking at it out your window.

I also expect I will not be able to get all four tunnels to be independent without radical measures like putting a remote receiver at one of the transmitter sites.

You might have to do that as long as can use an unused data stream on the STL or a dedicated phone line. It'll be interesting what you and big bosses agree as to a solution and how it works out.

73,

 

[Don_Burke]

Quick question, have you attenuated the tunnel freq/PL with the strongest signal. Just a thought, I have no practical reference.

They are all on the same RF frequency. Attenuation in the feedline or in the scanner will affect all of the signals the same and will not gain me anything in terms of capture effect.

I am pretty sure none of the easy ways will work, but thanks for the thought.

 

[Don_Burke]

WOW! I hadn't realized that (or if I had I forgot ).

I have not made a big deal of it and a surprising number of people have not noticed the change.

Obviously if you're at Sinclair there's no way you can attenuate Downtown since you're probably looking at it out your window.

I may be able to take advantage of the building itself to knock down some of the signal from the Downtown. There is a considerable amount of metal behind an antenna on the northwest corner. Mounting a couple of Yagi's on the mast that holds one of the STL dishes on that corner has possibilities for the Midtown.

The MMBT would involve some magic as I would be shooting over the Midtown.

The HRBT is not far offline from the Midtown, so there would be some magic there as well.

You might have to do that as long as can use an unused data stream on the STL or a dedicated phone line. It'll be interesting what you and big bosses agree as to a solution and how it works out.

At first, I would probably end up using the existing POTS line to the transmitter site as it is rarely needed for other things, especially in morning drive. If I can prove the concept, maybe I can free up some other resources.

Most of the stations have been around for a long time and quite a bit of old equipment has accumulated. There may be something in the pile I can press into service.

Some of the sites have high speed internet, so that is a possibility.

The TSLs are pretty much at capacity already.