Ground Loop / Audio Isolation Transformers

[clemfm]

I've just bought one of these off eBay for about $70 which is not cheap, however some Chinese junk sells for nearly as much.

JENSEN TRANSFORMERS, INC. - ISO-MAX® CI-2RR Stereo Audio Input Isolator

There is a single channel unit, however I didn't want to wait for one to appear and they are all $179-199 new!

http://www.amazon.com/Jensen-CI-1RR-IsoMax-Isolator-Jensen/dp/B00AQV02M4

http://www.amazon.com/Jensen-CI-2RR-IsoMax-Isolator-Jensen/dp/B00ASVWYCS

If you look at the curves and specs in the data sheet you'll see why. The frequency response is wide and almost perfectly flat. Used by audiophiles and way overkill for a scanner, however I want to know that I am removing as much hum and noise as is possible.

When I receive it, I'll run a few tests with Audacity and see if it helps as I have a slight hum.

Any other suggestions, I believe the Radio Shack unit works very well?

Ground Loop Isolator : Isolators | RadioShack.com

 

[ramal121]

An audio balun will do the same DC isolation as a ground loop isolator. They just require a little more effort to haywire up. Maybe two back to back with a cat 5 patch cable?

http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias=aps&field-keywords=audio+balun

 

[Bellingham_Scanner]

Instead of an expensive band-aid try grounding your scanner to your computer.

Run a wire, a braid of you have one from your computer case to the shield of the antenna jack.

Also some scanners just hum, I have an old scanner years of running 24/7 takes it's toll on the filter caps. Now it hums too much to use on my feed.

One more thing check your cables, an open stereo channel will cause hum. Plugging a stereo cable into a mono scanner earphone/external or a faulty stereo to mono adapter speaker can cause hum.