[time-nuts] Safely getting the electrical length of a connected antenna feedline
davidwhess at gmail.com
Mon Aug 8 22:14:51 EDT 2016
I actually tested various 74120 dual 4-input NAND drivers which
produce the sync output on my B&K function generator to find ones
which would provide the fastest and cleanest pulse. AS (advanced
schottky) and FAST (fast advanced schottky TTL) were the best for me.
Modern inexpensive discrete logic however can do a much better these
One interesting thing I learned is that the dual 4-input NAND pinout
overlaps the quad 2-input NAND pinout so in a properly designed layout
where only 2 gates are used, either part can be used.
On Mon, 08 Aug 2016 16:31:44 -0400, you wrote:
>If you have a function generator with a sync output, you can use that pulse
>into a T connector with your scope to do a TDR measurement of the cable. If
>you have a scrap of the new cable, you can use that to calibrate the setup.
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