Some transceivers come with a TRS plug input labeled "key".

When wiring my paddle or a straight key for these TRS connector inputs, is there any current standard for which key connection goes to which portion of the TRS? (tip, ring, or sleeve; left or right paddle closure; straight key closure).

Or do I need to make custom cables or a patch board for each radio at which I might find myself operating? (bring my own key + field day guest possibilities: Icom, Yaesu, Kenwood, Elecraft, et.al.) Or do some of these radios have a (panel or software) selectable key input configuration setting?

This question only has an incomplete answer for only one model of radio.

  • $\begingroup$ In my 44 years as a ham, I've never hear of the term TRS, so I added a link to its definition. Pardon my ignorance. :-) $\endgroup$
    – Mike Waters
    Aug 26, 2019 at 20:50
  • $\begingroup$ I posted one of the answers to the question you referenced. Although that OP was interested in a specific radio (which I did have experience) I have never run into any radio built in the last N years where my suggestion failed (N > 20 and N < 50).. Again, in my posted answer, the key benefit (in my opinion) is that you don't have to bother wiring the TRS plug itself, only connect the wires to your key correctly. If you do not have wiring instructions in manual or user guide, then trial-and-error works nicely in most cases. $\endgroup$
    – K7PEH
    Aug 27, 2019 at 2:36
  • $\begingroup$ Alas, at least two of the keys in my collection have no place to connect individual wires. Only another TRS plug/jack. And trial-and-error may or may not be acceptable when playing with somebody else’s radio. $\endgroup$
    – hotpaw2
    Aug 27, 2019 at 3:54

1 Answer 1


The sleeve/shield contact is always "common" between the two switch contacts.

I haven't had extensive experience, but the two radios with key inputs I have used both had settings for whether tip and ring were dot and dash or vice versa (or if a straight key was connected, disabling the internal keyer). Note that this setting isn't just useful for compensating for lack of standards — it also means you can swap the "handedness" of a paddle to your preference.

That said, if you're planning to use your key as a guest operator, it might make sense to have a hardware switch just so you can make it work the way you want without having to learn how the radio's settings menu works. A common DPDT toggle switch, suitably wired, will suffice to reverse the tip and ring connections — or you could have a box with two differently wired jacks and you plug a TRS-TRS cable into the appropriate jack.


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