In the May 2021 edition of QST Magazine, Stan Johnson (W0SJ) published an article describing a device one can hook to an oscilloscope to turn it into a time domain reflectometer (TDR). Stan built his basically out of parts from the junque box for which he deserves kudos!
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I hate hand wiring stuff so I decided to design a printed circuit board for it. My board makes a few changes in Stan¡¯s design which made the PCB layout a bit neater and added a couple of features, but otherwise it is basically the same as his design.
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With a lot of help from Glenn (VK3PE), the PCB can be built using either through-hole components or SMD components or
a combination of both.
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Also available there are two Android apps developed by Roderick Wall (VK3YC). One allows you to calculate the
length of a piece of coax and the other allows you to compute the velocity factor of a known length of coax.
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I have a few extra circuit boards available should anyone want one. You can have them for $5 each (free shipping to the USA). If you'd like one, please email me (good on QRZ.com).
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John P.
WA2FZW
John P