Bad Humm

[scottjengle]

I am using a Motorola XTS 3000 for Houston Police Department and a second for Houston Fire. On both I have a very loud humm. I have tried changing chargers and same issue. I have also tried just using it off battery and no change. I am using a Radio Shack ground loop isolator. I have tapped into the speaker output of the external microphone. Any ideas. The humm goes away as soon as there is a transmission and then comes back,
Houston Police - Digital
Scott

 

[w2lie]

Do both have a loud hum when not connected to a computer and running a feed, or is the hum only noticeable when hooked to a computer and a feed is running?

I have found that the best ways to remove any hums are to use mono cables only, don't use stereo patch cables. The other config step is to set your input volume as low as possible, then drive that with the volume from your radio, until you hear clipping. Then go back and adjust your inputs. If you are using a microphone input turn off the mic gain.

 

[Chrome69]

I have found you may have to try different audio cables as suggested before you find the right one, you may also wanna try a different computer. I ran into that problem with Acer for their poorly grounded power supplies for Notebooks. That was one of my problems, ended up running my feed off a lenovo notebook through the mic input... (no line in on my notebooks) You may also consider buying the Ground Loop Isolator Ground Loop Isolator : Isolators | RadioShack.com

 

[Eng3ineer]

Check your computer power supply not sure what you using, but you have close to what mine hum sounded like. I'm using a older dell laptop for feed computer and the power supply was the cause of my hum replaced it with new powers supply and the hum went away. This was after hours of trouble shooting and just about ready to pull out what hair have left trying to figure out the cause.

 

[jlesterca]

I would check the mic in settings on your laptop. If at 100% it will hum... We turned ours down to 20% and all is well