PRO-95 Scanner Cast Audio VERY Low

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LynchburgCSI

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Hey everyone. I'm setting up a stream using my old RS PRO-95. I'm running it from the headphone jack straight into the microphone input of my laptop. Unfortunately, the audio even when cranked is very low. I've tried adjusting volume on the mic in line and scanner with no luck. Cranking the volume also creates a lot of hiss.

I'm wondering what ground loop isolator people recommend for the PRO-95. I'm also wondering if I need an amplifier or something to raise audio levels. Any suggestions?
 

Eng74

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The GRE made radios have a limit on the headphone jack. There is a way to "short it" between the jack and something. There should be info online here for the 93/95/96 on how to do it. The hiss is a GRE trait and nothing you can do about it.
 

krokus

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Portable scanners have a dropping resistor on the ground side of the earphone jack, to cut the signal level.

There are a number of ways to bypass the resistor, or supply another chassis ground to that connection.

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LynchburgCSI

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The GRE made radios have a limit on the headphone jack. There is a way to "short it" between the jack and something. There should be info online here for the 93/95/96 on how to do it. The hiss is a GRE trait and nothing you can do about it.
I remember reading about that mod 5 years ago or so now that you mention it. I'm pretty handy with a soldering iron, so I'll look into doing that.

Are you sure a ground loop isolator wouldn't help?

Portable scanners have a dropping resistor on the ground side of the earphone jack, to cut the signal level.

There are a number of ways to bypass the resistor, or supply another chassis ground to that connection.

Sent via Tapatalk
Thanks! i'll look into that.

Found it! http://forums.radioreference.com/me...eaker-mod-external-speaker-pro-95-96-106.html
 
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gmclam

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Headphone audio out

I used GRE scanners when I was streaming. To get the level you want, connect the audio "hot" lead to the tip connection from the headphone jack. Connect the ground to the BNC antenna connector ground.

I also ran isolation transformers, although they are not typically required (depends largely on the sound input you're connecting to). Radio shack sells one that is ~$16 and that was too steep for me. I built my own, but had a local resource for parts to do so.
 

LynchburgCSI

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I used GRE scanners when I was streaming. To get the level you want, connect the audio "hot" lead to the tip connection from the headphone jack. Connect the ground to the BNC antenna connector ground.

I also ran isolation transformers, although they are not typically required (depends largely on the sound input you're connecting to). Radio shack sells one that is ~$16 and that was too steep for me. I built my own, but had a local resource for parts to do so.
I just did this "mod".. if you can even call it that. Take a listen for yourself. I don't think I need a ground loop isolator, but if you have details I'd love to look into making one for myself. There is a SMALL hiss if you listen closely.

Mod: http://forums.radioreference.com/me...eaker-mod-external-speaker-pro-95-96-106.html
My feed: Lynchburg Police, Fire, and EMS
 

gmclam

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I found the hiss is somewhat dependant on where you set the volume control on the scanner and where you set the input level on your sound card. I like to run the scanner volume at 11 o'clock max (~30%) and adjust to get proper modulation with the sound card input. If you have to turn the sound card input volume up too high, you'll hear a hiss from the scanner. Nothing an isolation transformer will resolve.
 
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