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Streaming / Broadcasting / Audio Recording - Interested in putting your scanner online for others to hear? Want to listen to other radios on the internet. This forum is here for you to discuss these topics related to streaming scanners online.

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  #1 (permalink)  
Old 07-26-2017, 4:25 PM
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Question Stridsberg Multicoupler causing Hum on my Feeds?

I recently bought 8 port Multicopler and when I hooked them up to my feeds I hear a loud hum. When I take it out replace it with a regular antenna the hum goes away. My question is the Multicoulper is plugged in so I wouldn't notice a loss. The 2 feeds so you can listen.

My question is this fixable or is this suppose to be like that? Stridsberg's website claims no loss with this. In the 8 port I have 2 other scanners plugged in for my personal use non feed.

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Old 07-26-2017, 4:50 PM
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I use 8 port and a 4 port Stridsberg multicouplers in my shack with 2 different types of outside antennas.
I don't have any issues even remotely close to yours. Could it be a power supply issue? I run mine off of a Rigrunner brand power strip connected to an Astron brand power supply. Again, no issues. Have you tried contacting Stridsberg directly? Those guys over there are great to talk to. I know when I first got mine, I called them and they actually suggested the power supply route versus the provided wall wart.

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Old 07-26-2017, 4:53 PM
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Quote:
Originally Posted by N1SQB View Post
I use 8 port and a 4 port Stridsberg multicouplers in my shack with 2 different types of outside antennas.
I don't have any issues even remotely close to yours. Could it be a power supply issue? I run mine off of a Rigrunner brand power strip connected to an Astron brand power supply. Again, no issues. Have you tried contacting Stridsberg directly? Those guys over there are great to talk to.

Manny
I have it plugged into a surge protector. I sent an email to Stridsberg seeing what I could be doing wrong. I notice on his website he offers RG58U for coax cable and I'm using RX8 Mini so I'm not sure if that maybe the issue the coax cable. I'm not familiar with the products you mentioned I'm not that tech savey sorry.
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Old 07-26-2017, 5:44 PM
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Put terminator connectors on the ports not in use. It eliminated a "buzz" I had at one time.

Example...
bnc terminator connector - Google Search
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Old 07-26-2017, 5:46 PM
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Quote:
Originally Posted by Terry1810 View Post
Put terminator connectors on the ports not in use. It eliminated a "buzz" I had at one time.

Example...
bnc terminator connector - Google Search
I have an 8 port so I would need 4 as I have 4 plugged in and that would get rid of the hum?

Do I just buy them and put in the ports I'm not using? Is that what you did?
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Old 07-26-2017, 5:51 PM
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Is the hum on the local (scanner) speaker or only through the feed?
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Old 07-26-2017, 5:54 PM
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Quote:
Originally Posted by KevinC View Post
Is the hum on the local (scanner) speaker or only through the feed?
I hear the hum through the feed.
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Old 07-26-2017, 5:56 PM
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This is a ground loop issue, not a multi-coupler issue.

Put a ground loop isolator on the audio cables between the scanner and PC, and the hum will go away.
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Old 07-26-2017, 5:57 PM
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Quote:
Originally Posted by NFR85 View Post
I hear the hum through the feed.
You probably introduced a ground loop. A search here will probably give results of how to alleviate this.
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Old 07-26-2017, 6:04 PM
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Quote:
Originally Posted by GTR8000 View Post
This is a ground loop issue, not a multi-coupler issue.

Put a ground loop isolator on the audio cables between the scanner and PC, and the hum will go away.
This is what I used not 100% if this is correct or not. And it did nothing. If it's not correct can someone point me in the right direction for the correct one.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
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Old 07-26-2017, 8:33 PM
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I just realized I'm using RX8 Mini and on Stridsberg site they offer RG58A/U. Could that be my problem?
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Old 07-26-2017, 8:54 PM
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Smile Ground loop

I concur that this is a "grounding" problem. I suspect that you are getting audio out of the scanner via the headphone jack. The problem is that the "low" side of the audio is connected to ground via a resistor in the scanner.

There are several solutions to this and the best choice depends on your exact setup. You might only need to connect the low side of the audio to a true ground. For me I used the antenna shield as my ground point. Other solutions include adding an isolation transformer on the audio. Regardless of what you do, be sure to monitor/set the audio level into your sound card.
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Old 07-27-2017, 10:01 AM
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Does any recommend what type of ground loop isolator I should get?
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Old 07-27-2017, 12:09 PM
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Would this work?

https://www.amazon.com/Valuepro-GRP-...009ZQ7GPE1G95W

https://www.tripplite.com/products/i...ransformers~25
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Old 07-27-2017, 2:51 PM
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Or this one? New Pyle PHE300 2 Channel Hum + Noise Destroyer W/ (2) 1/4" Inch Inputs & Ouputs | eBay

Could someone please advise.
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Old 07-27-2017, 4:30 PM
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The first link you posted is for a power isolation transformer. I doubt that will help. The latest link looks promising, but has the wrong connectors on it. Looks more like something for a guitar.
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Old 07-27-2017, 4:32 PM
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Quote:
Originally Posted by gmclam View Post
The first link you posted is for a power isolation transformer. I doubt that will help. The latest link looks promising, but has the wrong connectors on it. Looks more like something for a guitar.
Could you please provide a link that would work for me?
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Old 07-27-2017, 4:47 PM
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Are your antennas properly grounded? Try and make sure all your equipment is powered by the same 120V outlet. I use a 12V 30A PS to power all my scanners, a few pre-amps and two multicouplers. I have no ac hum issues at all. The problem is likely your connection between the PC and scanners. Is the PC properly grounded?
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Old 07-27-2017, 5:19 PM
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Quote:
Originally Posted by cpetraglia View Post
Are your antennas properly grounded? Try and make sure all your equipment is powered by the same 120V outlet. I use a 12V 30A PS to power all my scanners, a few pre-amps and two multicouplers. I have no ac hum issues at all. The problem is likely your connection between the PC and scanners. Is the PC properly grounded?
The antenna I got this June was grounded. Nothing else is grounded. Everything is plugged into a surge protector. Sorry for lack of info I'm not tech savvy I have to do alot of research on stuff YouTube.

I looked at the 12V 30A PS and it's not something I know how to do. Way to complicated.

Last edited by NFR85; 07-27-2017 at 5:26 PM..
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Old 07-27-2017, 6:48 PM
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You need to isolate the audio and that requires a ground loop isolator with an audio transformer, with separate input and output windings, to totally isolate the computer ground from the scanner ground. Not all have a real audio transformer in them.

How can you check? There must NOT be any continuity between any of the input side connections to any of the output side connections.
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