When I first went over to broadband a few years ago, only 10 watts on 160m
used to make the ADSL2 lose connection, even with a wireless system.
The house is fed with an overhead telephone line.
Of course it depends on location and systems, but after trying various
filters for months and months I fixed it with a combination of measures as
1. Common mode filter in series with Telco line where it comes in house,
just before ADSL splitter (splitter is a replacement faceplate on BT
2. Balanced LPF filter just before router/modem
3. New router/modem
4. Ferrite on DC lead
1. The common mode filter is about 30 turns of a twisted pair stripped from
CAT-5 loosely wound on a 1 inch ferrite core (unknown u - maybe RFI
suppression type). This really did make a difference in combination with the
LPF. (The recommended Type 31 ferrite might be better).
2. The LPF is based on the OZ1CTK design with some small variation of
components to optimise BB speed. Passband to 1.2MHz, 35dB attenuation on
Speed now 3MBit/s with filter.
3. Changing modem/router also made a big difference. New router/modem (Addon
NWAR-3670 cost £38) proved much more resistant to RFI than old one. With my
old Dynamode modem the filters were only partly effective. I also tried
another modem (2 year old Netgear) but it only produced a small improvement,
even 100w with filters caused the BB to unlock sometimes.
4. Ferrite on DC lead may not be necessary (I put mine on anyway, not tested
UR RST IS ... ... ..9 QSB QSB - hw? BK