Feed is cutting off and distorted, choppy at times

[Blind_Shadow]

I am having some issues that are driving me batty. One of my feeds varies from clear to completely unable to understand. It goes from clear, to choppy, to distortion ( not necessarily in that order ).

I have changed antennas, switched antennas, move location of both the radios and antennas. It seems to help for short time, but reverts back to what it was doing.

Besides user complaints, I have talked with a couple of other people. Being the system is P-25 digital, it obviously does not sound like analog clear.

Now this morning, while it as happening, I decided to listen straight from the scanner and not thru the feed and the scanner is clear, with very little issues in understand what is going on .

Now where is the problem lying?

Sounds like it is happening either when it leaves the scanner to the computer to be feed thru the software then goes into the feed system to the server that sends the feed out.

I use RadioFeed for the feed software on Win 7.

Any ideas, and help would be appreciated. I really do not want to kill the feed, but as it is right now, I would rather find a fix or something to make it properly audible and usable to listen to.

I have listen to some other digital feeds and those that I have listen to, they are clear and one can understand what is completely being said with out cutting off what is being said.

Thanks...

 

[Deziel0495]

What feed are you referring to? You have more than one, listing it can give people the chance to listen and see if they know the issue.

One thing to check would be audio levels. If something is turned too high, it can clip and cutoff audio, causing distortion, ect. Make sure there are no options checked for gain or boost, ect. Both on the scanner itself, and your computer's sound card.

In the RadioFeed software, If your feed is mono, make sure the feed is set to: Mode = Mono, Samples = 22050, Bitrate = 16. Go over all the settings in the software to make sure they are correct.

You said the scanner itself sounds fine, have you tried a different audio cable? Maybe an external speaker or headphones? Your audio out/headphone jack could be bad causing poor audio quality.

Good luck!

 

[flythunderbird]

Which one of your feeds is it?

Sounds like it is happening either when it leaves the scanner to the computer to be feed thru the software then goes into the feed system to the server that sends the feed out.

It almost sounds like the scanner's audio signal is too strong for the computer. Are you sending the audio signal to the computer through the computer's line-in jack or through the computer's microphone jack?

 

[Blind_Shadow]

ScanPEI:

< What feed are you referring to? You have more than one, listing it can give people the chance to listen < and see if they know the issue.

Topeka Police Dispatch - East and West

< One thing to check would be audio levels. If something is turned too high, it can clip and cutoff audio,
< causing distortion, ect. Make sure there are no options checked for gain or boost, ect. Both on the
< scanner itself, and your computer's sound card.

I have checked the audio levels from the radio. In the past I had the level lower, but some minor complaints that some users were having a hard time hearing the feed and they had their volume turn all way up. So I increase it. I will turn it down a notch or 2 and see if there is any difference

< In the RadioFeed software, If your feed is mono, make sure the feed is set to: Mode = Mono, Samples < = 22050, Bitrate = 16. Go over all the settings in the software to make sure they are correct.

Settings are set properly. Same way when feed was analog. Nothing there was changed on the change over

< You said the scanner itself sounds fine, have you tried a different audio cable?

Yes, I have changed out cables, made no difference as far as I can tell.

< Maybe an external speaker or headphones?

My headphones are hooked up to another separate computer.

I also tried with an external speaker and it seemed to me it was a little worse. Even with adjustment to volume on the speakers.

< Your audio out/headphone jack could be bad causing poor audio quality.

The scanner I had used to listen to check was not the feed scanner. It was a portable I was using to see If it was having the same issue directly.

I will try to work with volume adjustment on the scanner again and see if it makes a difference one way or the other.

Ri'c/

 

[Blind_Shadow]

flythunderbird:

< Which one of your feeds is it?

Topeka Police Dispatch - East and West

< It almost sounds like the scanner's audio signal is too strong for the computer.

I have checked the audio levels from the radio. In the past I had the level lower, but some minor complaints that some users were having a hard time hearing the feed and they had their volume turned all way up, so I increase it. I will turn it down a notch or 2 and see if there is any difference

< Are you sending the audio < signal to the computer through the computer's line-in jack or through the
< computer's microphone jack?

On this feed the signal is on the ' line in ' jack.

Ri'c/

 

[flythunderbird]

I'd like to suggest that you download the 'Digital Level Meter' from this page:

Audio Level Meter

http://www.darkwooddesigns.co.uk/downloads/SetupDigitalLevelMeter170.zip

The meter will give you an idea of audio signal strength going into the feed computer and you can rule that out as an issue. You can adjust the level with the volume control on the scanner and with the line input level adjustment in Windows 7. I'd suggest that you keep it around -12 or a little higher. Please advise what you find out ...

 

[Blind_Shadow]

flythunderbird:

Thanks, I had tried last year to use the Audio Level Meter from that site and it would not work. It works fine now.

I am a little confused tho, is the -12 you are talking about the db level? Keep the numbers to with in 2 or 3 above or below?

I have adjusted the audio level down on the windows mixer to 30, dropped the audio volume on the radio to 7.

There may be some difference, not real sure yet, need to watch and listen a little more longer. Am still hearing some minor choppiness.

However am not sure that the volume going out is loud enough. I have my volume on the computer that I listen to the feeds with almost 80% up, compared what I had previously had.

Overall it may be better, just need some others to listen to it for a while and give me feed back if possible.

And let it set in and run with these new changes.


Ri'c/

 

[flythunderbird]

Yes. -12dB is more-or-less equal to a line-level signal in this situation, which is what you're trying to approximate for the line input on the computer.

My suggestion is that you set the line-in level on the computer to 100 and then adjust the volume level on the scanner so that the Audio Level Meter stays at or near -12dB during normal radio conversation. If you can only turn up the scanner volume a small amount before overloading, then adjust both the scanner volume and the computer's line-in level to hit a happy medium between the two with normal radio conversation at or near -12dB on the meter.

Another thing to consider: is the audio control level on the source client tab in RadioFeed set to maximum (0dB) for your feed?

It is possible that some of the choppiness may be due to multipath distortion:

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

If so, there are some things that can be done to (hopefully) address it.

 

[talkpair]

I captured about 27 minutes of your feed this morning and viewed it with Audacity. The audio levels look good to me.
When I zoom in everything looks nice and rounded.

The cutouts I heard sounded like the typical problem scanners have with simulcast systems.

Here's the zoomed out view of the audio I captured:

 

[rcool101]

My 2 ¢

You want feedback? I listened to it Sun morning at 1:30AM, EST. on HTML5 player on Broadcastify. Also on ScannerLive. Both on my desktop. Not a thing wrong that I would change

 

[Blind_Shadow]

ScanPEI,
flythunderbird,
talkpair,
rcool101,


Thanks for all your input and suggestions. So far there is a definite improvement, not as choppy, not cutting off transmissions as bad and at least to me a little clearer.

Am still doing some fine tuning, but with all your help I believe we are real close to the best that can be done.

Again, Thank you for your time.

Ri'c/