Buzz, click, click,click!

[Offwego]

I have a Garmin 2720 and a chatterbox Communicator. I will probably got to the Starcom1 Advanced. I use the GPS with the motorcycle hardwire. If I plug a headset into the GPS output, it works fine. If I connect it to my Chatterbox, I get a click, click, click, buzzzzing sound. I've tried making Messenger13's multi box with 10k and 4.3k ohm resistors, but it only reduces the volume. What the heck is wrong?

[Big_E]

This will sound werd but, it's the only way mine worked on my Wing. Try this, plug the audio jack in all the way then back it out one click. You are getting the same noise I got on my Wing when I plugged in my 2620. It was something to do with the way the system was grounded. All I did was back the plug out a little & tapped it up, never bought the $200 gadget that allowed it to be plugged in all the way.

[Offwego]

Tried it..... next idea? Inotice when I start to plug the GPS into the Chatterbox, just touching the tip causes the same buzz. I tried a different wire, so it's not a short. I've also tried plugging into the Chatterbox music input as well as the aux input. Both the Chatterbox and GPS are wired to the battery +/- terminals.

[scurrie]

You are on the right track, there is a "ground loop" between the audio leads and the power leads. The right way to fix this is with a ground isolation transformer in the audio lead. These can be purchased, and are usually pretty expensive since they use high quality transformers (intended for high quality stereo sound), but since this is a GPS, we can get buy with much less. If you are good with a soldering iron, go to Radio Shack and pick up a 1:1 transformer and make up a cable, wiring one side of the transformer to the GPS and the other side to the Chatterbox. See attached picture.

-Scurrie

[Big_E]

I have also heard of people splitting the cable & cutting the ground loop.

[Offwego]

You are on the right track, there is a "ground loop" between the audio leads and the power leads. The right way to fix this is with a ground isolation transformer in the audio lead. These can be purchased, and are usually pretty expensive since they use high quality transformers (intended for high quality stereo sound), but since this is a GPS, we can get buy with much less. If you are good with a soldering iron, go to Radio Shack and pick up a 1:1 transformer and make up a cable, wiring one side of the transformer to the GPS and the other side to the Chatterbox. See attached picture.

-Scurrie

Offwego to Radio Shack! I will advise outcome tonight!

[Texas42]

radio shack has an isolation transformer that is $2.69 works great. When you get to the Escort Radar detector then you will need the one from Excort, I couldn't make one that worked, but their $25 cable did the trick.

[Offwego]

radio shack has an isolation transformer that is $2.69 works great. When you get to the Escort Radar detector then you will need the one from Excort, I couldn't make one that worked, but their $25 cable did the trick.

My Radio Shaq looked at me like I was some sort of biker freak. I called first and they checked their computer and said they had 3 in stock. When I got to the store the guy said "no, we dun't kerry nun ov dat stuff" The manager then looked in a drawer and said "no we dun't got it" I live in Miami and English is not the primary language! Anyway, I'll have to order it off the web.

[Texas42]

I get the same response, I just printed off the picture and they went oh that's what that is. It was hanging right there they just didn't know what it was. It took four (4) of them to find it.

[Offwego]

You are on the right track, there is a "ground loop" between the audio leads and the power leads. The right way to fix this is with a ground isolation transformer in the audio lead. These can be purchased, and are usually pretty expensive since they use high quality transformers (intended for high quality stereo sound), but since this is a GPS, we can get buy with much less. If you are good with a soldering iron, go to Radio Shack and pick up a 1:1 transformer and make up a cable, wiring one side of the transformer to the GPS and the other side to the Chatterbox. See attached picture.

-Scurrie

Ok, I got the 1:1 transformer from The Shack. I cut my homemade mono cable and soldered it in line and then tried it. No more buzzing or crackle but the volume is soooo low I can barely hear it even with my volume all the way up. Any ideas on what's wrong here? Did I wire the transformer backwards?

[Offwego]

Ok, I got the 1:1 transformer from The Shack. I cut my homemade mono cable and soldered it in line and then tried it. No more buzzing or crackle but the volume is soooo low I can barely hear it even with my volume all the way up. Any ideas on what's wrong here? Did I wire the transformer backwards?

Ok, now for the follow up. I made the ground loop isolator and Messenger13's extra connector majic box. I connected my Ipod and GPS to the majic box and then connected the magic box to the Chatterbox's audio input. The GPS is connected with the isolator cable And it works! Thanks to everyone for all you help.

[scurrie]

Ok, now for the follow up. I made the ground loop isolator and Messenger13's extra connector majic box. I connected my Ipod and GPS to the majic box and then connected the magic box to the Chatterbox's audio input. The GPS is connected with the isolator cable And it works! Thanks to everyone for all you help.

So on the first try, were you connecting the GPS and the iPod with a Y cable? That could explain the low volume if the iPod was loading down the GPS audio output.

-Scurrie

[Offwego]

So on the first try, were you connecting the GPS and the iPod with a Y cable? That could explain the low volume if the iPod was loading down the GPS audio output.

-Scurrie

First go I tried to connect the IPod to audio and the GPS to AUX on the Chatterbox. Then I tried to connect using Messenger13's majic box, both to the AUX, but had the buzzing. Then tried the ground loop isolator on the GPS and that eliminated the buzz, but the volume was too low. Then connected gps with ground loop to majic box and IPod to majic box to aux. Then after all else failed the connected IPOD and Gps with isolator on GPS lead to audio input and it works! I had a lot of fun with the soldering iron. I think my aux input is malfunctioning. So, Y connector won't work as the GPS is hard wired to bike and gets a buzz. It has to have a ground loop isolator as pointed out to me. Perhaps using it and a Y would work, I don't know.

[GBaker]

I too am having the same issues. Would be pleased to know what "Messenger13's extra connector majic box " is. :cool:

Thanks

Gene

[Offwego]

I too am having the same issues. Would be pleased to know what "Messenger13's extra connector majic box " is. :cool:

Thanks

Gene

This allows you ta add two items to one input.
http://www.bmwlt.com/forums/showthread.php?t=21880

He's smart!

[GBaker]

Thanks Craig.

Gene