[AMPS] 50:75 ohm matching

[frank ayers jr]

Carl wrote -

>The way I heard it is that 25 Ohms is best for power transfer, 75 for low
>loss and 50 was the compromise.
>RG-8 came out sometime during WW2 as a result.

Tis true
For a particular outside size of cable, the lowest loss is at 77 ohms,
maximum breakdown voltage is at 60 ohms, and the highest power handling is
at 30 ohms. 50 ohms is the best compromise.
This explains why cable TV line is 75 ohm; power and breakdown voltage
ratings are not important so the stuff is optimized for low loss.


Frank
W2FCA

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