On 7/16/2012 6:10 PM, N1BUG wrote: > I had exactly the same problem, tried the same "cures" you have. The > problem is ADSL uses frequencies up to 1.1 MHz. The modems are > easily overloaded by 1.8 MHz RF. Nothing worked until I built this > simple filter designed by OZ1CTK:
Looks great, Paul. Thanks for posting this. This is a differential mode filter, so it suggests that some or all of the telco cable feeding the modem isn't twisted pair, or isn't very good twisted pair. SO -- another solution could be replacing that poor cable with CAT5, using the pair within the CAT5 that has the highest twist ratio. Shielding is NOT important, but TWISTING is. Un-twisted cable is notoriously bad for RF rejection. KL7RA's advice is also quite good -- the problem is poor rejection of the 160M signal by the DSL modem and/or its wiring, and we should lean on our service providers to fix that, either with new hardware/wiring, or filters, or both. 73, Jim K9YC _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK