swr pwr

After building my Z-match tuner, I wanted to design a circuit board for a Stockton type swr/pwr meter that I could reproduce easily and see how small I could make it. The result is in the above picture. It is a board that measures a scant 1` x 1. 5` and is made from common single sided copper clad board. I drew the lines on the board with a pencil,
swr pwr - schematic

and then used a Dremel tool and an abrasive wheel to cut the traces in the copper that isolates the individual pads that the components solder to. The circuit is a variant of the Stockton type of bridge used in many commercial swr/pwr meters and kits these days. The design calls for a short piece of coax going through each toroidal sensor with the shield grounded at one end only to eliminate harmonic currents, but I am going to experiment with just an ordinary piece of insulated wire due to the fact that my circuit will be used at QRP levels only. Will let you all know how this works out once I get it all tested. Figure 1 above shows the PC board dimensions and pad locations. You could etch this board, but it is so simple, it is real easy to just sketch the lines on the board using a pencil and ruler and then use the Dremel tool to cut the traces. Figure 2 above shows the board with the parts location marked. As you can see, the design is straight forward and parts count is minimal. The circuit and board is so small that it will fit inside many QRP rigs. The only thing wrong with that is the fact that it may be hard to find a panel meter small enought to fit the rig. The circuit will fit easily inside an Altoids tin, and there are many old CB radios out there that you can rob the meter out of that is small enough to fit the Altoids tin also. You can also fit this circuit inside that QRP antenna tuner you have been planning...

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