How to fix humming on my feed

[SlipNutz15]

I have my feeds all set up the same. Scanners connected to my servers the line-in port like the audio setup picture shows on the website. ( Setting up your Broadcasting Station - The RadioReference Wiki )

What I've noticed, even though the audio is clear, is all my feeds seem to have an electrical hum/buzz during the quiet parts of the audio. How can I fix this so my feeds are full quieting unless someone is talking? I'm looking for ideas such as maybe switch to USB audio cards, 12V rig runner, audio filters, etc).

My feeds:
Juniata Fire/EMS
Juniata County Fire and EMS Live Audio Feed

Mifflin Fire/EMS
Mifflin County Fire and EMS Live Audio Feed

Mifflin Law Enforcement:
Mifflin County Law Enforcement Live Audio Feed

 

[ak4fn]

ground loop Isolator

Are you using a ground loop isolator?
http://forums.radioreference.com/scanner-receiver-antennas/235385-hum-audio-antenna.html#post1719139

 

[SlipNutz15]

Not currently because I wasn't sure which kind to get (brand).

 

[rbm]

I use quite a few of these, but I see the price has increased a LOT over the last year or so.

Amazon.com: Kensington Noise Reducing Car Audio AUX Cable for MP3 or SmartPhone, including iPhone 4S: MP3 Players & Accessories

I think I paid around $9 each for them and you may still be able to find them at a reasonable price or something similar to them.

Rich

 

[SlipNutz15]

The only issue I see with that cable is it doesn't work with my setup because my cables have RCA connectors like the wiki page showed because my feeds are set up for stereo

 

[rbm]

The only issue I see with that cable is it doesn't work with my setup because my cables have RCA connectors like the wiki page showed because my feeds are set up for stereo

They're made that way also.
Radio Shack used to carry one. I don't know if they still do.

While I haven't used any of them, here are a few others.

Examples from ebay:
RCA Phono Ground Loop Isolator Hum Noise Eliminator Car Radio Amplifier Filter | eBay

and from Hong Kong:
3 5mm Car RCA Amplifier Audio Noise Filter Ground Loop Isolator Suppressor | eBay

and from the U.S.:
Ground Loop Isolator Noise Suppressor Filter Killer RCA to RCA 15 Amp | eBay

Soundquest RCA Ground Loop Isolator Sqgli 1 Noise Filter Brand New | eBay

RCA Ground Loop Isolator Noise Kills Hum Audio Filter | eBay

Rich

 

[SlipNutz15]

Did anyone listen to my feeds to hear what I was talking about? I just want to verify it's not another issue.

 

[rbm]

I did listen to it.

It's not so noticeable on the Juniata County feed.
Worse on the Mifflin county law.
And worst of all on the Mifflin county Fire and EMS

It sounds like AC hum to me.

A good isolator 'should' help.

Unless you can hear it on the scanner speaker. (Or, you may be able to hear it using headphones)
If you hear it there, it's likely a problem with the scanner power supply.

Are you using 'wall wart' power supplies? If so, you could try another one to see if that makes a difference.
They WILL cause some hum if they are under rated.

Rich

 

[SlipNutz15]

Yes, I'm using wall warts that why I had mentioned about maybe going to a 12V supply?

 

[Eng3ineer]

Yes, I'm using wall warts that why I had mentioned about maybe going to a 12V supply?

I'd start here by getting rid of the wall warts they were my biggest problem when I first started streaming feeds and had bad hum issues as well.

Quick temp test get you 12 v battery source hook it up to one of the feeds while listening and you should hear the hum drop out. It was night & day for me when I did this test.

Other hum issue that came up couple weeks ago turned out to be the power supply for laptop running my feeds it started causing intermittent hum every 5-6 seconds. After few test trying other cords and such I put one of these on http://img.alibaba.com/img/buyoffer/295415600/Grounded_AC_Plug_Adapter_3_prong_to_2_prong.jpg for temp fix until can replace the power cord.

After trying the above if still have hum like sound check your audio output under sounds. Go to sounds, then playback, then levels. I've found if you have these too high/hot it cause a hum/hiss like sounds as well.

If you listen to my Miller County Feed which is digital Miller County Sheriff and Fire, ASP Troop G Dispatch you can hear it when radio traffic is quite. I have to run the feed volume hot other wise I get low audio reports.

 

[SlipNutz15]

Thank you for the input. I will mess around with different options. I know they recommend using the line-out (scanner) to line-in (computer) option but the audio from the scanner isn't loud enough. Any way to make this audio louder so it's not using the headphone jack port?

 

[pkneeyahx]

try grounding the antenna connector and see if that helps.. if its a mobile radio ground one of the screws on the back. or the ground screw if available.

when i had this issue a while back i used to ground the antenna connector to a screw on the back of my pc. solved the humming issue right away.

 

[SlipNutz15]

It's two scanners into the line-in port via stereo headphone jack to RCA cable. No mobiles. I'll have to look into the common ground thing. Thank you all that are replying!

 

[Eng3ineer]

Thank you for the input. I will mess around with different options. I know they recommend using the line-out (scanner) to line-in (computer) option but the audio from the scanner isn't loud enough. Any way to make this audio louder so it's not using the headphone jack port?

Not sure if you can adjust the line out for scanners.

I don't have any scanners / radios that have the line out so i'm tied to using the headphone output. I run headphone volume at half maybe little more other than my Miller Co. feed it's close to max. I then further adjust the levels under computer sound.

 

[SlipNutz15]

Not sure if you can adjust the line out for scanners.

I don't have any scanners / radios that have the line out so i'm tied to using the headphone output. I run headphone volume at half maybe little more other than my Miller Co. feed it's close to max. I then further adjust the levels under computer sound.

I do the same thing. I wasn't sure if the hum was also a result of using the headphone jack vs the line-out

 

[SlipNutz15]

Well I got a 12V Pryamid converter for my Juniata feed. It definitely fixed the issue! Full quiet! I have another one ordered and should be in by week's end and then it's going for my Mifflin County feeds. Thank you, again, for all those who responded and PMd me. Greatly appreciated.

 

[Eng3ineer]

Well I got a 12V Pryamid converter for my Juniata feed. It definitely fixed the issue! Full quiet! I have another one ordered and should be in by week's end and then it's going for my Mifflin County feeds. Thank you, again, for all those who responded and PMd me. Greatly appreciated.

Glad it worked out sounds great on this end...

 

[SlipNutz15]

Ok well half of my feeds got fixed. My Juniata feed is as good as it ever has been. The two mifflin county feeds are still having issues.

Here's what I did so far and issues that I've found:

1. Removed wall warts from both scanners and the 4-port multicoupler and got a 12V converter power supply.

2. Got a new sound card for the server.

3. Got a better shielded audio stereo headphone to RCA cable.

4. The really bad hum went away but now there's a higher pitched noise from the feed and I can't figure it out. PLEASE LISTEN TO THE FEEDS TO HEAR IT.

ALSO!!!! My police feed scanner appears to be acting as an open mic to ambient sound and pics up people talking and any tapping of the case of the scanner. I've seen that this has been reported with a PRO196 scanner I believe. My police feed scanner is a GRE410 and I have no clue why it's picking up background noise. HELP!!!

 

[SlipNutz15]

Well I swapped out scanners and it has appeared to fix the issue so far. Still not as full quiet as Juniata feed but it's not as bad as before.

If anyone listens to my feeds and feels I can fix anything or make it better please let me know.

Thanks again for all the response.

 

[SlipNutz15]

Ok, help me again. I woke up to my scanner feed frying! It was def hardware related. I removed the old sound card and plugged directly into the sound card on my mother board and it slightly fixed the issue so I tried another sound card and it made my one scanner act like a microphone. It's working but I'm not happy because there's background noise.

Anyone have experience with USB sound cards? I saw a feed that used multiple ones like from eBay that were $1/each and they seemed to like them. I need to fix this feed asap. Do USB sound cards eliminate feed hums and whatnot?