[Elecraft] K3 Tune button, does not key a linear

[Mike Greenway]

If you just punch the XMIT button it just puts the K3 into xmit with no RF out but if you hold the XMIT/TUNE button for 2 seconds or so I will put out RF so you can tune an amp or whatever.  I find this an extremely useful function and use both often.  73 Mike K4PI