150W_PA

150W_PA_6m

This page shows the 150W driver PA for 50MHz that I use. It is build from an old plastic-bag sealing equipment. This used RF-energy to heat the plastic and in that way melted the bags' opening togehter.

Because like many RF-amplifiers one can purchase, also this amplifier was not set to the correct bias. I needed to add a small circuit that was able to set the correct working-point. After this was done, I was able to achive 100W+ from the double MRF422 transistors:

In the above picture the completed PA for 50MHz can be seen. Nice details are the BD135 power transistors that are thermally connected to the RF-transistors. This makes the amplifier thermal stable. There are no real connectors placed in the walls of this PA, there are fixes RG58u cables ending in BNC mounted.

I realise there are transceivers available at the market nowadays that have 50MHz@100W build in, but one part of this nice hobby is building stuff. I find great joy in doing so and besides this, it keeps the costs down :-)