[TenTec] Jupiter - Such a Quiet Puppy

[jimimaxi2 at comcast.net]

Thanks for all the responses. 
I use the RF gain at 75% most of the time. 
The "sssssshhhhh" sound in the background of any signal, whether I am listening to a transmission or an empty frequency drops considerably when the attenuator is applied on the Jupiter. 
I guess what I am talking about is that on the Kenwood and Yaesu I hear that same "sssssshhhhh" sound with all attempts to quiet it failing. 
I don't hear the sound on the Jupiter without any buttons engaged. 
Why? 
Better radio or I don't know how to eliminate it on the other two radios? 

THanks, 
Jim C 
KC2ROF