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Wiring My X-Phase RFI Fighter

wiring my x-phase

Wiring my X-Phase QRM Eliminator kit was fairly easy, but here are a few things to keep in mind if you build one of these.

My RA0SMS X-Phase board and kit of parts arrived complete. You will notice a double sided PCB and a combination of surface mount (SMD) and through hole (THT) parts. Putting the kit together is mostly just soldering, but you also have to assemble one transformer on a binocular toroid core.

My old egg carton came in handy for sorting out the parts and making sure each was present and identified. All of your parts have markings, except the diodes, but they are obvious. You will need a microscope or magnifying glass to read the markings on the SMD capacitors and resistors. I found it simple to check the codes on all the resistors and capacitors online to confirm their values.

I started wiring my X-Phase with the SMD parts on one side of the board. Now, this was my first experience with 0805 form factor parts, which are really tiny. Since I have a digital microscope, solder paste and a hot air iron, using the normal method of heating and flowing solder paste worked nicely. If you have no experience with mounting SMD parts, I suggest you get some experienced help.

Wiring the THT parts was simple, as was winding the input transformer.

My only problem was discovering that the three PCB mount potentiometers did not properly fit into the PCB holes, which were drilled slightly small. So, I very carefully used a round-tipped tool to slightly widen the holes, maybe 5%. That did the trick.

Wiring My X-Phase – Some Suggestions

I like to make disassembly easy. So, I added some pin headers for the antenna, PTT and LED resistor connections. These make it easier to solder and un-solder without touching the PCB itself.

The RA0SMS board has a bottom-side ground plane that runs around its perimeter. I use the mounting screws and spade lugs to attach RF and power ground to the plane, as shown above. I sprayed on some conductive paint for shielding.

When you fabricate a plastic box, you should make allowance for mounting tabs on the potentiometers as well as the scalloped shapes of the BNC screws. If you do these right, you get a much more sound mechanical fit with no stress on the wiring.

Now I will 3D print some knobs and test performance.

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