Audio "Hiss" on Live Feed

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emt603

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Hello Everybody, i'm a newbie here and i just set up my live feed. I'm using a Icom PCR100 Computer Controlled Scanner that i ran into a Soundblaster 16 bit sound card. I have a "Hiss" that is being fed into the soundcard while the scanner is scanning without any traffic and i can't seem to get rid of it. I can see this "Hiss" on the VU meter on the Oddcast server software and its about -45db. i've adjusted volume all the way down, tried the mic jack instead of the line inpit jack on the soundcard, and i can't seem to even dampen it a little. The voice traffic streams nice and clear when the scanner stops on a channel that has traffic, if i could just get rid of the "Hiss" that is being streamed when it is scanning.

Any idea's???



Mike
 

hvscan

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Same advice from me. I've tried different ground loop isolators and find that the Radio Shack model seems to work best. You can sometimes find them at a discount on eBay. It only comes with one adapter and you'll need a second, which is available at Radio Shack in the audio cable section.
 

Tweekerbob

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May 27, 2004
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What you probably need is an 8 Ohm to 1000 Ohm transformer. Remember the audio output of the PCR-1000 (and most "headphone" jacks) are typically 8 Ohms impedance. The "line-in" jack on your typical PC soundcard is 1,000 Ohms. You will achieve much more volume control as well as isolate the radio from the PC. Also, you're being nice to the audio amp inside the radio.
 

kc2rgw

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Also, wasn't sure if you did this.

Crank the audio output of the scanner up good and loud and just barely open the mic gain on the computer for the input side. If you have the 'mic boost' on, you are way too low for output on the scanner. You should be able to run the scanner out loud enough that it won't distort but your PC mic gain slider for the input is just barely opened.

This will vastly reduce the hiss that most soundcards have when gaining up the pre-amps on their inputs and outputs.

Just don't overdrive coming in or you will have a distorted signal.
 
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