I published this on e-ham back in 2001 regarding the Bencher YA1 low pass filter. I have no idea why it worked but it did. If you have a low pass filter (or can borrow one) give it a try.
When reading the recent survey on e-ham, I noticed that over 50% of all hams have had some sort of RFI problem in the past. I was thinking how lucky I was not to have experianced that, when my downstairs neighbor stopped me on my way upstairs to my new apartment to complain about voices coming out of her telephone and stereo. Looking inside her apartment I could see I had a problem: her stereo consisted of one of those piece of junk plastic all-in-one units, with speakers placed all around her apartment connected by long runs of unshielded speaker wire placed under the carpet. The telephone was a $25 cordless unit.
My rig is a Kenwood TS130s running through a Kenwood 130 tuner into a 85' longwire in the trees (I usually operate 15-80). I use a T-Kit (Ten-Tec) counterpoise for my RF ground as I live on the second floor of an apartment building. My neighbor lives right below me. Longwires are notorious for RFI problems, a reputation well deserved as I just found out. I decided to buy the Bencher YA1, the most expensive RFI filter I could get (about $25 more than most), but also having the best specs. Since I have started using the YA1, I have had no complaints what-so-ever, nothing. I consider my situation to be the acid test of a RFI filter, I can't imagine a worse situation. The Bencher solved solved my problem, and has allowed my to stay on the air. I give it my highest recommendation.