You should probably connect the radio to a ground.  It's good safety 
practice if nothing else.
Were the antennas moved as part of the shack relocation?   How long has it 
been since you had the station running?  If you shut it all down 3 months 
ago  to make the move, the bands  have gotten  noisier since then. 
Summertime noise on the lower bands is just a fact of life, and  worse in 
your part of the country.

Is the AC  power in the shack a new installation?   Try running a long 
extension cord from the rig's power supply to  a outlet inside the house and 
see if the noise improves.

A few sources for ferrites other than Radio Shack are:
amidon, Palomar, all electronics, and The Wireman.

You would probably want the snap on type instead of the doughnuts,  since a 
doughnut large enough to slip over the connector would be too loose on the 
cable.


73, Steve KW3A