Humming sound when plugging my scanner to my computer

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Blockmade925

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when plugging my scanner into my computer it instantly makes a humming sound, I tried messing with the sounds and mic but still humming and even went to radio shack and bought different audio plugs, can someone please help me, Thank you... PerryJayStewart@gmail.com
 

Gene

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Solution to induced hum

I used to use two of these taped together with electrical tape to isolate a tape recorder or computer from a scanner. One acted like a small speaker and the second one picked up the sound and was used like a microphone.


Telephone Pick-Up Coil with Suction Cup | 36-010 (36010) | Distributed By MCM


They worked quite well and there was no hum induced into the recorder .

Old school solution to a new school problem.
 

whsbuss

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I used to use two of these taped together with electrical tape to isolate a tape recorder or computer from a scanner. One acted like a small speaker and the second one picked up the sound and was used like a microphone.


Telephone Pick-Up Coil with Suction Cup | 36-010 (36010) | Distributed By MCM


They worked quite well and there was no hum induced into the recorder .

Old school solution to a new school problem.
Do you have that plugged directly into the headphone or ext. speaker jack on the 536?
 

Mike_G_D

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I was almost going to suggest that telephone pickup coil in the other thread; didn't know if they even still existed! Anyway, for how to use them - couldn't be simpler - all you do is plug the telephone pickup coil into the input of whatever you are wanting to feed (like a PC audio input) and then take the suction cup and stick it to the back of whatever speaker you are using! That's it! The coil in the pickup acts like the secondary of a transformer with the primary formed by the speaker coil. Now, of course, the problem is that you might have difficulty on some speakers keeping the suction cup attached. You want to find a smooth surface (like maybe the back of an external speaker (assuming it is smooth and not well shielded). It would also work fine, usually, when placed right on the speaker grill right in the middle where the voice coil is. But then, of course, the grill won't allow the suction cup to stay stuck. So you'd have to find some other way to keep it "stuck" like with tape or whatever. Anyway, these are really easy to play with and SUPER SAFE for those paranoid folks out there! Talk about no direct connections!! They also can work in reverse, albeit not as efficiently, if you can drive them enough - they will impose a signal on another coil.

Aside from the "stickiness issue" another problem might be shielding - if the external speaker you are using is well shielded it might have very low or no signal level. But it's really easy to experiment with these babies and, like I said above, you can't really get much safer!

-Mike
 

JamesO

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Do you have that plugged directly into the headphone or ext. speaker jack on the 536?
Ideally you would likely use the headphone jack, however, some people prefer the rear connection AND some folks like to also be able to monitor their $600 radio, so some will connect to the external speaker jack, split the output, half of the split may go to an amplified speaker or a volume L-pad for the monitoring speaker, the other half may go to a resistive attenuator to then feed a line level device.

The issue is you cannot adjust the volume knob without impacting the line level you are deriving unless you do far more work than you should. So in this case you use an external amplified speaker so you can adjust the local listening volume without impacting the line level feed.

Would have been SO much easier and simpler if Uniden would have supplied a standard line level output like earlier models. The change with the external speaker Amp design has caused a lot of confusion and headaches.
 

bob550

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when plugging my scanner into my computer it instantly makes a humming sound, I tried messing with the sounds and mic but still humming and even went to radio shack and bought different audio plugs, can someone please help me, Thank you... PerryJayStewart@gmail.com
Is your computer and scanner plugged into the same electrical outlet or surge protector? Is the hum coming from the computer speakers or the scanner? Are you using a speaker output, headphone, or record-out jack on your scanner. Are you using a line or mic input on your sound card? Lastly, are you using a mono or stereo audio cord for the connection? I know. I'm sounding like Tech Support. :)

Try the simple stuff first: Make sure the plugs are seated firmly and securely in both the computer and scanner.
 

JamesO

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Is your computer and scanner plugged into the same electrical outlet or surge protector? Is the hum coming from the computer speakers or the scanner? Are you using a speaker output, headphone, or record-out jack on your scanner. Are you using a line or mic input on your sound card? Lastly, are you using a mono or stereo audio cord for the connection? I know. I'm sounding like Tech Support. :)

Try the simple stuff first: Make sure the plugs are seated firmly and securely in both the computer and scanner.
The issue is with the BTL design of the audio Amp for the external speaker and maybe even the headphone output that does not use the chassis ground and you end up with ground loops due to AC power and antenna feeds as well as you may have a loop due to the shield of the 1/8" plugs.

Also the telephone monitoring device can be used as the other person mention, purchase 2 and take them together, then you do not need to worry about speaker coupling.
 

SCPD

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when plugging my scanner into my computer it instantly makes a humming sound, I tried messing with the sounds and mic but still humming and even went to radio shack and bought different audio plugs, can someone please help me, Thank you... PerryJayStewart@gmail.com
I know this thread is a few months old but I just solved this without spending a dime. I hooked up an external yagi 800 MHz range antenna for my Radio Shack PRO-163. After I did, big-time hum when plugging into the computer for my feed. It's definitely a ground issue. I grounded the antenna ground to the outlet ground where both the computer and the scanner are plugged into. That reduced about 1/2 the hum. Then, I grounded the ground side of the 1/8" female plug where I have my "Y" connector going to the computer and my external speaker, also to the ground of the same outlet. Made a plug from an old computer power cord, cut off the flat pins and left the ground pin. Ran to a connector I fashioned to capture the ground barrel on the female Y connector. Hum all gone.

Ground loop isolators are nice and they'll work, but I like to try and solve the problem without having to throw anymore money at the project.
 

kb9hgi

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You're having symptoms of a ground loop problem. Get something to isolate the two devices (like this Ground Loop Isolator : Isolators | RadioShack.com) and your issue will probably be resolved. You'll probably also need a couple of these (RadioShack Gold Series Audio Y-Adapter : Y-Adapters | RadioShack.com) to convert from the stereo mini-phone connector on the scanner & computer to the RCA connector on the isolator.
Which end plugs into the scanner the long cord or the short cord?
 
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