PITA Hum

[rfoster]

Last night is the first night in a while for us to dry camp.

I have a PITA hum coming thru the rear overhead Bose Speakers when the bus is parked for the nite, Gen is off and we are running on batterys. Any suggestion as to what is causing this?

Is it that the Bose System doesn't like the sine wave coming out of the inverters now? Is there such thing as a filter for the power source?

Maybe there is too much reflection of bling and it is making a noise?

I had to fire up the generator to eliminate it so I could enter dreamland. It is that annoying.

I am in the coach now and my next project is to get rid of that hum when I get home.

Thanks in advance to all you electronic gurus for clues

[dale farley]

I think it is your inverters.

[mike kerley]

Yep. Its the inverters! We had the same problem in our Beaver years ago. The fix is not an easy one. You must "rebuild" the electric current feeding the Bose. Transformers needed to do this are heavy and get hot. Bose simply does not like the modified sine wave (or square wave) that most inverters produce. Eventually, I gave up and installed a different sound system. Cheaper than a new inverter!

[truk4u]

King,

Can't you kill the power source (fuse or breaker) to the Bose system while your trying to get to dreamland?

[JIM CHALOUPKA]

The best one is to teach it the words, you know no humming.

Next you could turn off the unit.

We get the same sound plugged into 120v ac at home with the surround sound. Can't stand surround sound.

JIM

[dalej]

Roger, I would think that your coach is new enough that your inverters are the pure sine wave type.

I had to install a line conditioner when I installed our Bose. It cost me about 500 back in the early 90's.

[merle&louise]

Roger,

I had the same problem; it was the surround sound. The volume on the surround sound was too high, when I turned it down the humming went away. Simple fix!

[Jon Wehrenberg]

Roger, The best part of all this is I know you know I am spring loaded to break your chops. But I won't right now. But I remember all this stuff. I'm still bitter over having the King of Bling award ripped from my hands.

Some guys create mole hills, some guys let the sheep loose, some guys get blow up dolls. Hmmmm, what will your reward be?

[sawdust_128]

Pink Earmuffs??

[JIM KELLER]

Roger, Our Bose does the same thing if the volume is turned up too high at the switching center.