Useful sites on RFI: http://www.arrl.org/tis/info/rfigen.html and http://www.fcc.gov/cib/Public_Notices/heee1.html and http://www.fcc.gov/cib/Publications/phone.html Here is a picture of a typical telephone choke installation: http://k5gp.home.texas.net/rfchoke.jpg The ferrite toroid in the picture is a 2.4" toroid I ordered from Amidon at http://www.bytemark.com/amidon As you can see in the picture, I try to get as many turns on a choke as I can. You may have to install several chokes to get rid of all the RFI. If the telephone is an older electronic phone, it may be picking up RF right out of the air and will need to be replaced to get rid of the interference. This is usually not the case. To order, call 1-714-547-4494, order FT240-77 (2.4" toroid $9 ea), FT140-77 (1.4" toroid $3.75 ea), and 2X43-151-1 (split core $2.12 ea). I use a tie wrap to hold the split core sections together on the 2X43. The 77 and 43 means they are type 77 and 43 ferrite materials, giving maximum inductance on the HF bands. The 2x43 works great on phone lines and small wires, especially if a phone line is running in the attic and has enough slack on it to allow about 10 turns on the 2X43, and you can't easily open one end of the line, then the 2X43 is the choke to use. The FT140 is the least effective in choking off RF but works well on phone lines if you get as many turns on it as you can. The big FT240 allows many turns and is big enough to handle power cords and coax. Put one of the FT240 chokes on your coax lead-in from your antenna. Get as many turns on it as you can. This will reduce RF in the shack. That will help reduce interference on all the devices in your house. Put a choke on the phone lead-in with the interference. If the phone has a power cord, put a choke on the power cord also. If you still have interference, temporarily connect another phone at the same point and see if it does or does not pick up the RFI. If it doesn't pick up the RFI, then maybe the phone first phone is picking up RF out of the air and is too sensitive to RFI. That phone may have to be replaced. I eat the cost of a new phone myself. I have spent as much as $150 buying my next door neighbor a fancy new phone, but one that I knew would not have interference (because it was once my own phone). Chokes may be needed on cables connected to your computers. I had to put toroid chokes on my keyboard line and on the mouse to knock out interference to the PC on 10 meters (with 1000 watts to antenna - hi). On TV sets, put a 2.4" ferrite choke on both the antenna (or cable) lead-in as well as the power cord. Make sure the ham rig is not xmitting RFI on the TV frequency. If the TV is picking up the ham signal and getting interference directly, then the TV will need to be replaced. This might occur for 15 meters where older TVs used a 21 MHz IF stage. New TVs (newer than ancient - hi) should not have this problem. PC and sound system speaker wires are notorious for picking up RF. You may have to use 2.4 inch toroid chokes with many turns on speaker wires, power cords, and other audio cables. If you can go to the newer digital stuff, you will get less interference (and hum) than analog audio. Getting rid of RFI on large surround systems may be the most difficult task since all the wires act like antannas on the ham bands and easily pick up RF. This has been my most difficult area to removing RFI. Keep spare toroid chokes handy for when a problem arises. When you have a problem, keep adding chokes until the problem is gone. However, if you install a choke and it does not give any improvemenst at all, then remove it and use it at another location where a real reduction in RFI is observed. I have had instances where I had to install two of these chokes in series along a telephone line to get rid of all the interference. This might be because installing a choke may fix one band and make a problem worse on another band by creating a new resonance (new antanna effect) on another band. However, two chokes will kill the resonance effect on both bands. The complete removal of all RFI will take some testing and experimenting. Don't give up. You will succeed.