Band Pass Filters (MiniKits)

For my multi station DXpedition I had built some different BPF’s, all in the 100 W category. Since I have now a station configuration with a SPE Expert 1.3K -FA amplifier, I got a different situation. The amplifier need very little drive power (max. 10 W) which did me think of making smaller BPF’s. I have search the internet for several designs and construction details but finally came across MiniKits in Australia. They had BPF kist available that could handle up to 10 W.

I have ordered kits for 160, 80, 40, 30, 20, 15 and 10 meters (https://www.minikits.com.au/electronic-kits/filter-kits/hf-bandpass-filters) and purchased the Hammond 1550Q enclosures locally. The kits are of high quality!

Making the coils is easy but takes some time and soldering the SMD capacitors need some skills. I drilled all the enclosures and mounted already one BNC chasis part on the enclosure. Next I cut a foam pad that could fit at the bottom of the enclosure. The followin step was to slide the PCB into the enclosure with one side under the two M3 bolts that hold the BNC part. Next I mounted the other BNC chasis part and made the connection from the BNC to the PCB.

Now the testing was done for which I used the miniVNA. In some case I could fine tune a bit by compressing or stretching the windings on the toroid. However, in some case I needed to remove one or two windings.

I ordered some additional PCB’s in order to build also BPF’s for 12 and 17 meters.  I decided to use BNC connectors as this works quicker when changing bands.

Here are the test results from the filters I have built, measured with miniVNA.