High power dummy load


A high power dummy load could be found second hand.

It took some time and planning to transport it from France to my QTH but is was worth the effort.

Nevertheless it took some additional work to get it up and running.

The connector was an EIA-alike type of connector, but not quite.....The centerpin was 3 mm thicker.

So some dedicated mechanical work was needed to make an adapter to 7/16.










Once again Jos, PA3ACJ, provided help and using his lathe did construct a superb 50 Ohm taper from semi-EIA to 7/16.

The outside shield as well as the inside conductor are tapered, providing a 50 Ohm impedance at any point along the way.













A full blown picture just to give an impression of the size of the dummy load.

It is filled with oil and weigths approx. 30 kg.

Blowers underneath allow CW powerlevels upto 5kW.



The dummy load return loss measurements :

> 40 dB upto 50 Mc

approx. 25 dB at 144 Mc

>20 dB at 432 Mc.






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