Curious to know "why?"

mully95 · #1 (**permalink**) 01-30-2013, 6:28 PM

I was wondering why is it that if I listen to the online scanner

Anderson County, South Carolina (SC) Live Police, Fire, and EMS Scanners on RadioReference.com

on the P25 system that it comes in much clearer than my BCD996XT scanner. I'm less than ten miles from the systems tower. I know hills and trees have a whole to do with it but I'm pretty much away from those. The scanner is hooked to a 800mhz antenna on a pole attached to my chimney pointed in the correct direction in which it is 20 ft from the ground. I have adjusted, tweaked, read up on all the suggested ways of making my scanner come in clearer but it never has sounded as good as the online scanner.

Just curious. Does anyone know what type of electronics are used to produce such a clean signal? Is it just a direct connection to the agencies? I've gotten to the point that I really don't bother turning on the scanner because I can here it on my lab top. The only thing however is I can't "hold" it on a certain TGID if I here something interesting.

thanks

SquierStrat · #2 (**permalink**) 01-30-2013, 6:49 PM

Quote:

Originally Posted by mully95

Just curious. Does anyone know what type of electronics are used to produce such a clean signal?

The feed provider may be using a GRE scanner.. lots of people agree GRE scanners, overall, do a better job of decoding p25. simulcast or not

mully95 · #3 (**permalink**) 01-30-2013, 6:59 PM

Quote:

Originally Posted by SquierStrat

The feed provider may be using a GRE scanner.. lots of people agree GRE scanners, overall, do a better job of decoding p25. simulcast or not

I have been kicking the idea around for awhile to get a GRE scanner. However the economy and my job status isnt allowing that right now. I don't think I'm up for Home Patrol quit yet either. I have enough Uniden products. Would like to try something different. I know that the GRE scanners are the ugliest little scanner........ but when you want nice clear reception looks really doesn't matter does it? lol

Anyone know who is over the creation of the online scanner that might shed some light on the subject?

kg4pbd · #4 (**permalink**) 01-30-2013, 7:00 PM

There are a lot of variables here, the least of which may be the scanner you are using.

You mentioned your antenna is outside. How long is your coax run and what type of coax are you using? If it's a yagi what kind of gain are you supposed to get with it.

I listen to a P25 system that drove me nuts until I gave up and put a yagi in the attic along with LMR400 coax. Now it works perfectly well. And by the way both my P25 radios are Uniden, and they work great with the right antenna.

mully95 · #5 (**permalink**) 01-30-2013, 7:16 PM

Quote:

Originally Posted by kg4pbd

How long is your coax run and what type of coax are you using?

38ft of LMR400

Quote:

Originally Posted by kg4pbd

If it's a yagi what kind of gain are you supposed to get with it.

It's a yagi (I can remember how long). It's every bit of 2' I believe.

Quote:

Originally Posted by kg4pbd

I listen to a P25 system that drove me nuts until I gave up and put a yagi in the attic along with LMR400 coax. Now it works perfectly well. And by the way both my P25 radios are Uniden, and they work great with the right antenna.

It's like sometimes it does REALLY good and then sometimes it's REALLY bad. There seems to never be a middle. It's not all out terrible but it isn't as good as listening to the scanner online. The online scanner has a 30 secs delay time too. I forgot to mention that.

kg4pbd · #6 (**permalink**) 01-30-2013, 7:31 PM

Have you tried a different orientation for the antenna? Sometimes pointing it off-axis works better. That and trying the system with attenuation on are about all I can add.

mully95 · #7 (**permalink**) 01-30-2013, 7:38 PM

Quote:

Originally Posted by kg4pbd

Have you tried a different orientation for the antenna? Sometimes pointing it off-axis works better. That and trying the system with attenuation on are about all I can add.

I was fixing to ask how sensitive the orientation of these antennas are? I have not tried turning it any. Thought about getting one of those "motorized turners" so I don't have to go up and down the ladder. Like turn it with the motor and let it scan for a day see how it goes then turn it a little more until I find the sweet spot. I tried the attenuation without noticeable difference. Maybe I should go at it again. It all might need some fine tuning.

Thanks for the advice.

kbehning · #8 (**permalink**) 01-30-2013, 7:53 PM

Depending on how many cross bars your yagi has, it can be extremely directional. But in general you should consider it to be many times more deaf on the rear side (the long bars) than on the listening side (with the short bars).

Also, very important to ensure you get the most reception of your agencies, you want the antenna oriented in the vertical plane, ie with the tines facing up and down, not flat. This is called vertical polarization and the vast majority of the signals that we'll want to scan are vertically polarized. I believe you can lose about 20 dB of signal if your polarization is opposite of what it should be.

KZ9G · #9 (**permalink**) 01-30-2013, 10:33 PM

Another thing to ponder is, do you have the latest firmware for your scanner. They just released an update this week that should improve simulcast if you have that there.

mully95 · #10 (**permalink**) 01-31-2013, 5:11 PM

Quote:

Originally Posted by kbehning

Depending on how many cross bars your yagi has, it can be extremely directional. But in general you should consider it to be many times more deaf on the rear side (the long bars) than on the listening side (with the short bars).

Also, very important to ensure you get the most reception of your agencies, you want the antenna oriented in the vertical plane, ie with the tines facing up and down, not flat. This is called vertical polarization and the vast majority of the signals that we'll want to scan are vertically polarized. I believe you can lose about 20 dB of signal if your polarization is opposite of what it should be.

I posted a picture of my yagi. I believe it's shorter than what I thought. Thanks for the info.

Quote:

Originally Posted by KZ9G

Another thing to ponder is, do you have the latest firmware for your scanner. They just released an update this week that should improve simulcast if you have that there.

Gosh I didn't know that. I will look and make sure I have the latest firmware. I probably don't since it was released this week. Thanks!

n5ims · #11 (**permalink**) 01-31-2013, 6:18 PM

Quote:

Originally Posted by mully95

I was wondering why is it that if I listen to the online scanner

Anderson County, South Carolina (SC) Live Police, Fire, and EMS Scanners on RadioReference.com

on the P25 system that it comes in much clearer than my BCD996XT scanner. I'm less than ten miles from the systems tower. I know hills and trees have a whole to do with it but I'm pretty much away from those. The scanner is hooked to a 800mhz antenna on a pole attached to my chimney pointed in the correct direction in which it is 20 ft from the ground. I have adjusted, tweaked, read up on all the suggested ways of making my scanner come in clearer but it never has sounded as good as the online scanner.

Just curious. Does anyone know what type of electronics are used to produce such a clean signal? Is it just a direct connection to the agencies? I've gotten to the point that I really don't bother turning on the scanner because I can here it on my lab top. The only thing however is I can't "hold" it on a certain TGID if I here something interesting.

thanks

I know it may sound silly, but it may be that you have too much signal so your scanner's front end is overloading and causing you problems. This is especially a problem with simulcast systems or in high RF areas. Have you tried lowering your antenna, using an attenuator, or even using an antenna with much less gain than your current one (perhaps even a combination of these)? You may be surprised how much better things sound with less signal reaching your scanner when you have an overload problem.

mully95 · #12 (**permalink**) 01-31-2013, 6:44 PM

Quote:

Originally Posted by n5ims

I know it may sound silly, but it may be that you have too much signal so your scanner's front end is overloading and causing you problems. This is especially a problem with simulcast systems or in high RF areas. Have you tried lowering your antenna, using an attenuator, or even using an antenna with much less gain than your current one (perhaps even a combination of these)? You may be surprised how much better things sound with less signal reaching your scanner when you have an overload problem.

No I havent tried any of this. What I have done tonight is installed the latest frimware. Now I'm listening for some positive changes. Haven't listen long enough to comment.

Before I broke down and bought the yagi and all I needed I wasn't to impressed. After the installation I could tell a big difference. Now that you mentioned overloading I have unhooked the yagi and installed the telescoping antenna that comes with the scanner. The scanner went dead. Hooked the yagi back up and within seconds I had traffic. wow I have a rubber ducky 800mhz antenna that I used on the 996 but it's on my 396 at the shop where I work right at the moment. The ducky did a better job than this telescoping antenna. As I'm typing this it seems the scanner is doing much better. I can hear the full length of the words in the traffic and it seems clearer. To me the scanner is faster at decoding than it was.

ka3nxn · #13 (**permalink**) 01-31-2013, 7:01 PM

The 996 has a signal meter. What does the signal look like on the meter? If it is full scale then the problem is not weak signal. If it is 2 bars or less then try adjusting the antenna for a stronger signal. If you have a full signal and are trying to get it in even stronger then you will get front end overload which will sound lousy like you aren't getting enough signal when the exact opposite is what is happening. What does the signal meter show? How many bars? I know it's not a true S-meter, but it's an indication of what maybe happening.

mully95 · #14 (**permalink**) 01-31-2013, 7:12 PM

Quote:

Originally Posted by ka3nxn

The 996 has a signal meter. What does the signal look like on the meter? If it is full scale then the problem is not weak signal. If it is 2 bars or less then try adjusting the antenna for a stronger signal. If you have a full signal and are trying to get it in even stronger then you will get front end overload which will sound lousy like you aren't getting enough signal when the exact opposite is what is happening. What does the signal meter show? How many bars? I know it's not a true S-meter, but it's an indication of what maybe happening.

I have 5 bars showing.

The squelch is set on "00"
If I turn the squelch up to "12" or higher I lose traffic. Even if I go to "5" it starts going down hill. I remember Upman telling me that leaving it on "00" helps with P25.

I'm still getting garble ever so often.

mully95 · #15 (**permalink**) 02-21-2013, 4:48 PM

Well it seems the online scanner is coming in crappy today. Not as clear as it usually sounds. Reminds me of the way my scanner sounds. lol

http://www.radioreference.com/apps/audio/?ctid=2316

bama9999 · #16 (**permalink**) 02-21-2013, 6:30 PM

Another thing to think about on the digital systems, is that sometimes the garbled sound isn't caused by your scanner, but from the transmitting radio not getting into the repeater strong enough. I use a Radio Shack Pro197 to listen to the MSWIN P25 system some, and have heard some mobile/portable units sounding garbled and the base radio and other mobile/portables sounded fine. In fact, I've heard the dispatcher tell the garbled mobile/portables that they couldn't copy them clearly either, so I knew for sure it wasn't a problem on my end.

Of course that wouldn't explain why the online stream was clear and your scanner reception wasn't, but it's just something else to consider when dealing with a digital signal.

mully95 · #17 (**permalink**) 02-21-2013, 7:56 PM

Quote:

Originally Posted by bama9999

Another thing to think about on the digital systems, is that sometimes the garbled sound isn't caused by your scanner, but from the transmitting radio not getting into the repeater strong enough. I use a Radio Shack Pro197 to listen to the MSWIN P25 system some, and have heard some mobile/portable units sounding garbled and the base radio and other mobile/portables sounded fine. In fact, I've heard the dispatcher tell the garbled mobile/portables that they couldn't copy them clearly either, so I knew for sure it wasn't a problem on my end.

Of course that wouldn't explain why the online stream was clear and your scanner reception wasn't, but it's just something else to consider when dealing with a digital signal.

Oh yeah I see what you're saying. I to as well have heard the same thing from the dispatcher. I guess that will be the chief complaint from the dispatchers if they are asked how the system is doing. Then I assume that is why they start looking for better, newer systems I suppose.

Thanks for the info

ofd8001 · #18 (**permalink**) 02-21-2013, 9:02 PM

Have you tried tinkering with the P25 Adjust Mode and Level settings? Sometimes that can make a difference in simulcast systems.

Also you might be listening in an area that has bad overlap of multiple sites, but the feed provider is lucky to be fairly close to a transmitter site and thus not affected by the overlap. It's amazing how just a short distance can make. I can receive our simulcast well in place, but move a quarter mile and it becomes garbled.