2kW Low Pass Filter for SW Amps

PCB pictures

This filter board has a lot of "iron", its not lightweight, but this is fine for the amount of power it should handle.

Where to buy:  www.helitron.de/shop


the board is made with 70um copper. We use 16A relais.

The maximum current at 2kW is : I = sqr(P/R) = sqr(2000/50) = 6,3Aeff or 9Ap-p. Use thick coaxial cable for wiring, recommended RG-142.


this is the fully assembled board (click to zoom):

a closer view of the high band filters:

the input / ouput pads are on the left side. The 6m filter bank is as close to the in/ouput as possible to keep stray inductance low. Followed on at the right by the 12/10m and 17/15m filters. At the right side of the picture you see the 30/20m filter bank which uses both air-coils and ring cores.

The silver plated wire has been replaced with normal enamelled copper wire. This works very well, no need for expensive silver wire.

a closer view of the low band filters:

build with big T200 cores these filters can handle a low of power without getting hot. The red capacitors are FKP1 which are cheap, available as 2kV types and work well up to the 40m band.