Electronic – How to plug the homemade Yagi Antenna into a wifi USB dongle

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I have made my own Yagi antenna and I would like to see if it works or not. I made the antenna based of these instructions: Easy to Build WIFI 2.4GHz Yagi Antenna

So I have soldered a coax cable to the pin 2 (the driven element). The center connector to one side and the shielding to the second side of the paperclip. But I have no idea how to actually connect it to my wifi dongle.. Does the center connector of the coax go to the "on board antenna" and then the shielding to the USB ground? also is the antenna the trace to the left of the dongle? The wifi dongle is an old Netgear w111v3. Any tips for me? Thanks!!

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Best Answer

possible RF connection The solder-resist is absent from the marked area, suggesting that this connection point may have been used by the manufacturer to verify that this dongle meets a RF specification. It appears to be close to the antenna feed point.
That said, there's no way to tell what impedance the RF sees at this point, or how you could impedance-match to this point.

Andy has pointed out that a balun would be good where you attach the unbalanced coax to the balanced driven element. This could be a ferrite sleeve slipped over the coax. There are alternative balun approaches. Unbalanced drive can skew directivity.

A caveat: Any blog boasting easy-to-build 2.4 GHz directive antenna is suspect. Your antenna is a very narrow-band design - measurement tolerances are critical, and impedance matching is difficult.

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