Talk:Coaxial cable

RG-142

RG-142 often used in aircraft, not test configuration only.

References

L and C

In electronics, L and C are commonly inductance and capacitance. This article, confusingly, wants to use them as inductance/length and capacitance/length. The article could, near the top, explain this unusual usage. I believe some use l and c, but don't know of a WP:RS for that. Gah4 (talk) 08:30, 26 May 2024 (UTC)

I will check a few, but I believe upper case is the clear majority. Constant314 (talk) 10:00, 26 May 2024 (UTC)

The following use upper case letters: Brian C. Wadell, Johnson & Graham, Edward F. Vance, Gupta, Metzger, Miano & Maffucc1, Karakash, Albert A. Smith, Harrington, Hayt, Kraus, Jordan & Balman, Ramo & Whinnery & Van Duzer, Marshall & Skitek

The following use upper case script letters: Walter Weeks

The following use lower case letters: Clayton R. Paul, Skilling, Magnusson Constant314 (talk) 10:31, 26 May 2024 (UTC)

Thanks much. I am remembering from some reference from some years ago. It mostly matters if you need both near each other.

I do still believe that the article should state early that they are the per unit length variables, to avoid confusion. Gah4 (talk) 06:15, 27 May 2024 (UTC)

"Coax" listed at Redirects for discussion

The redirect Coax has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2026 February 8 § Coax until a consensus is reached. TheTechie^[she/they] | talk? 06:00, 8 February 2026 (UTC)

Balanced vs. Unbalanced

The assertion that "coax is unbalanced" appears throughout this article, but that assertion is not actually true. "Balanced" and "unbalanced" are not essential properties of any type of transmission line. But, in order for to coax to fulfill the purpose for which it was invented, it must be driven by an unbalanced signal source. I'm not expert in the subject, so I won't try to describe it in detail, but AFAIK;

• Coax is expensive relative to other types of transmission line, and
• The reason for paying the extra price is that the outer conductor (a.k.a., the "shield") prevents the signal's electric field from interacting with other, nearby conductors, but
• The shielding effect only works if the shield is "grounded," and
• "Grounding" is only meaningful if the signal is unbalanced.

That is why, in nearly every application where coax is used, the coax carries an unbalanced signal. ~2026-82628-0 (talk) 16:04, 7 May 2026 (UTC)

We need reliable sources for all those assertions. However, the transmission line itself is unbalanced in the sense that there is a substantial difference in the two conductors. Constant314 (talk) 16:18, 7 May 2026 (UTC)

We don't tend to think about it, but there are three currents applicable. The current on (the outside of) the inner conductor, on the inside of the outer conductor, and on the outside of the outer conductor. (At least for not too low frequencies.) This is especially seen when you connect coax to a wrong impedance, or a balanced, antenna. The outside current will then radiate like an antenna, which you usually don't want. Ferrite beads can be used to absorb that signal. There should be WP:RSs, but I didn't look. At low frequencies, it doesn't matter, though not much reason to do it. Gah4 (talk) 06:59, 10 May 2026 (UTC)

Series inductance

The formula is not correct because there is an old confusion between Lo and L...Lo = pi2 x L..

So L =1/2pi x mu zero / pi2 x l x ln D/d and Zo = pi x square root of L/C equal to square root of Lo/Co ... It is the same for parallel wires transmission line...All of this can be verified by LC resonance...Leveugel (talk) 11:03, 3 June 2026 (UTC)

With transmission lines it is common (near universal) to use $L$, $C$, $R$ and $G$ for the per-unit-length parameters - see §L and C above. catslash (talk) 12:42, 3 June 2026 (UTC)

Yes, for calculations , what I call Lo , Co , Ro, Go...

But Lo is circular and Co is linear, so L= Lo/pi2 and C= Co...

There is the same problem with the circular loop and straight wire self-inductance ( Inductance topic )

So , the value of the straight wire become superior to the circular loop value of same length...

The reverse of the theory specified in " Source of inductance " Leveugel (talk) 16:00, 13 June 2026 (UTC)

As always, you need reliable source. Constant314 (talk) 13:44, 3 June 2026 (UTC)

Proposal: Create a list article

Move the ever growing list of coaxial cable types to a list article and refer to it in this article. Constant314 (talk) 04:03, 8 June 2026 (UTC)

Seems like a good idea - might be worth reviewing WP:SAL if you have not already done so. catslash (talk) 12:54, 8 June 2026 (UTC)