Topband: Cable Modems

[Jim Brown]

On Thu, 17 Jan 2008 21:20:42 -0500, Bill Gaines AD8P wrote:

>ne from the modem to the telephone that everything cleared up when 
>transmitting on 40 but when I send the first "dit" on 160 it gets 
>knocked off. Does anyone have any suggestions

Two suggestions. First, I hear that there are commercial filters 
that fix this pretty good on 160. Second, you might try a multi-turn 
ferrite choke designed for 160M, following the guidelines (and 
measured data) in my RFI tutorial. If the interference is being 
picked up common mode on one of the cables, that should fix it. 

http://audiosystemsgroup.com/RFI-Ham.pdf

FWIW -- I've had NO problems with a cable modem here in Santa Cruz 
or two different DSL modems back in Chicago.  

73,

Jim K9YC