DC Simulcast

[04Z1V6]

Has something changed? Is it that I have multiple simulcast towers programmed? My feed is breaking up at times and it driving me crazy. I run pro-197's for the feeds.

 

[Spitfire8520]

P25 simulcast is, in my opinion, the 2nd worst thing that can happen to the scanning. By the very definition of simulcast, you will end up receiving signal from multiple towers.

For actual radio users, the usage of simulcasting increases the coverage footprint of a P25 site. Unfortunately, scanners are not built to handle simulcast properly and has lead to what some call simulcast digital distortion. It has become quite a big complaint in the hobby and has yet to be seriously addressed by any of the manufacturers.

One can try to "fix" the issue by trying to isolate a single tower through attenuation and/or directional antennas. These are discussed in the simulcast distortion link. Unfortunately, it does not always work. You may also want to consider programming alternate (non-simulcast) sites to get around the distortion problems. I might be able to throw together a list of alternates if you are interested.

 

[natedawg1604]

P25 simulcast is, in my opinion, the 2nd worst thing that can happen to the scanning...

Amen and Amen! Simulcast is an evil curse for scanner users, and it's only getting worse as more and more agencies deploy it. In my view, the best/cheapest solution at present is OP-25 (a SDR program requiring linux & a cheap rtl sdr dongle), it fully supports simulcast and has great audio; unfortunately for most people it's very painful & time consuming to install.

 

[04Z1V6]

Thanks guys, i will try and hit the other towers and get the simulcast sites out of the program, the problem for me is I am in one of the holes that this helped fix for DCSO and CRPD my cell coverage sucks in my area to.

 

[jim202]

Thanks guys, i will try and hit the other towers and get the simulcast sites out of the program, the problem for me is I am in one of the holes that this helped fix for DCSO and CRPD my cell coverage sucks in my area to.

You might be outside the designed footprint. If so, your probably screwed.

It will take trying to pick up only one tower and basically nulling out the rest. That is not easy if your outside the designed area. It will take a really sharp or shielded antenna.

Something like a corner reflector antenna design might be needed.

 

[natedawg1604]

If you can receive any simulcast tower signal, then you could certainly decode everything just fine with OP-25. Some have also reported good simulcast performance with DSD+, that is much easier to install (you would need 2 rtl sdr dongles, which can be found here for dirt cheap)

You could also get the new Unication G5 for an out-of-the box simulcast solution, it's a bit pricier than any scanner but much cheaper than commercial radios & programming software. But given the high cost of these hardware options, you may want to seriously consider getting familiar with software defined radio, it's easier than ever these days to get SDR programs like DSD+ and SDR# up-and-running...

 

[radio]

I am reading how simulcast is not good.

However, isn't the current problem with the multiple towers where an agency is transmitting on one tower and then the next transmission uses on a different tower just as bad, or worse?

I would think simulcast would be the ultimate solution.

I'm confused.

 

[K0RUSinCO]

Well, I'm legitimately not trying to call anybody out or anything, but I've been pleasantly surprised that my BCD-436 seems to be working pretty well on the new Aurora phase 2 system, even all the way over in Littleton with a pretty marginal path.

Of course, I have nothing else set up to compare its reception with to prove that it isn't missing transmissions, but based on the conversations I've followed at times, I don't think it is.

In general, as long as it works, I do like simulcast as it is more efficient to scan than DTRS with the requirement to scan multiple sites.

 

[Spitfire8520]

I am reading how simulcast is not good.

However, isn't the current problem with the multiple towers where an agency is transmitting on one tower and then the next transmission uses on a different tower just as bad, or worse?

I would think simulcast would be the ultimate solution.

I'm confused.

I do not really see the current multiple tower setup as much of a problem if you know what sites to monitor. A properly programmed scanner will have sites that will have many dozens of users affiliated to that site, and therefore will not lose the talkgroups programmed. It might be less desirable for talkgroups that might have very few users, but at least scanners tend to work with these sites.

Simulcast is a terrific solution for public safety radios. It uses less frequencies while providing coverage for larger areas. It works on actual radios because they are designed for it. A lot of times, it is terrible for scanners. I will not get into the fine details, but the method that scanners use to try and handle simulcast does not work well.

Examples of simulcast issues:
Uniden BCD536HP / RS PRO-197 - Simulcast Distortion Vid 1
Uniden BCD536HP / RS PRO-197 simulcast distortion - Video 2

Occasionally heard on:
Broomfield Police and North Metro Fire/Rescue
Adams County Sheriff, Brighton, Northglenn and Thornton Police
Adams County Fire
Elbert and Douglas County Law Enforcement

As can be heard with the live feeds, stationary monitoring might be alright once you have a proven setup. It still shows itself from time-to-time, but you will notice that the public safety users generally do not notice it. Unfortunately you will likely find areas that scanners begin to fail spectacularly when mobile or portable.

Well, I'm legitimately not trying to call anybody out or anything, but I've been pleasantly surprised that my BCD-436 seems to be working pretty well on the new Aurora phase 2 system, even all the way over in Littleton with a pretty marginal path.

Of course, I have nothing else set up to compare its reception with to prove that it isn't missing transmissions, but based on the conversations I've followed at times, I don't think it is.

In general, as long as it works, I do like simulcast as it is more efficient to scan than DTRS with the requirement to scan multiple sites.

Simulcast issues have tons of variables. Little things like moving a scanner or antenna a few inches can immensely change the performance. A radio that properly handles simulcasting does not really have nearly as many problems, especially one that is within the intended coverage area.

While I generally have heard that the x36HP generally handles some of the issues better, it is not immune (as seen in the above video). When it works, it can be great.

 

[radio]

Thanks for the info Spitfire.

 

[04Z1V6]

Yes, Thanks. I have removed the simulcast towers and it sounds much better, DCSO goes digital but typically I hear dispatch call out that the unit has gone digital.

 

[desstony]

Yes, Thanks

 

[ShyFlyer]

I have about a 50/50 success rate with the DouglasNorth Simulcast site on my 436, so I just permanently locked it out. All the stuff I monitor in DougCo I can receive much better on Riley Peak, Arapahoe Admin, Chevron Plaza, Smoky Hill and even Franktown if I'm east if I-25.

 

[W2bdp]

Does the database show towers that I may be able to work with/change? I am in Brighton with a Pro197
at the junction of 7 & 85.

Thanks

 

[Spitfire8520]

Does the database show towers that I may be able to work with/change? I am in Brighton with a Pro197
at the junction of 7 & 85.

Are you asking about Douglas County or Adams County?

 

[ShyFlyer]

This might be what you're looking for:

https://www.radioreference.com/apps/db/?action=siteMap&sid=329&type=rr

It will show the Sites within the CO-DTRS system as balloon-shaped pins. Click on one and it'll give you the name of that Site.

You can get a map like that for any trunked system in the RR Database by going to that system's main page and click the link "RR Locations."

If you're not already aware, all of Adams County uses the FRCC system.https://www.radioreference.com/apps/db/?sid=7768

 

[W2bdp]

Thanks for the tower information. I will check it out. I am in Adams County. Scanner was origionally programmed in 2009 so a few changes are probable.

 

[bailly2]

i am right between two towers that are simulcasting. very distorted audio so i built a yagi. that helped a little, still distorted. so i put the antenna it came with into a hole in the side of an empty paint can near the bottom. can hear it clearly now ..or maybe surround the antenna with cardboard and aluminum foil in a similar shape

 

[W2bdp]

I just downloaded a csv file for Adams County Simulcast and of course have a question. I think that
frequencies in the file show control channels ?

In my Pro-197, I have about 5 control channels programmed. If I add/remove freqs. will that make reception better ? Not sure if transmissions move around towers.

I haven't found a list for control freqs for a certain tower.

 

[natedawg1604]

I just downloaded a csv file for Adams County Simulcast and of course have a question. I think that
frequencies in the file show control channels ?

In my Pro-197, I have about 5 control channels programmed. If I add/remove freqs. will that make reception better ? Not sure if transmissions move around towers.

I haven't found a list for control freqs for a certain tower.

If you're trying to monitor Adams County Simulcast with any regular scanner, it will be painful. You'll have to spend hours experimenting with different antenna positions, not fun. The only thing that works for me is a XTS 5k (works 100% all the time), I'm sure a Unication G4/G5 would also work great.