On Thu, Sep 24, 2020 at 7:52 PM MIKE ZANE <n...@comcast.net> wrote: > Need a little help. I just bought a KX3 and have it working OK. I also > have a 45w amp that I would like to work with the kx3. However, with no > info on the keying line coming from the amp, I have no idea if its Ok to > use.
See https://www.hfunderground.com/board/index.php?topic=29686.0 > I see in the Elecraft manual that the "keyline" and tip would be used to > connect to key the amp. On the KX3, the ACC2 connector (a 2.5 mm stereo or "TRS" jack), TIP is PTT IN (for a footswitch or computer-generated PTT if you set *ACC2: IO* to *LO=PTT*), and ring is KEYLINE OUT (for an amplifier). So RING of ACC2 is the one to connect to key the amplifier relay with a KX3. I can't tell which of the sections on a TRRS jack to use. Ring 2 or ring 3? The only TRRS jack on the KX3 is the MIC jack. Ring 2 is Logic Ground and Ring 1 is PTT IN (push-to-talk switch) or UP/DOWN. Do not connect the mic. jack to the amp. Also don't know how much current is on that amp key line. Measured 15V DC > when it is on and off measured 400 ohms, if that is any help. Just put your meter into "AMPS" or "MilliaAmps" on the highest scale, and measure the current across the KEY IN or "RELAY" jack of the amp with the meter while it is powered ON. The amp. should go into TX mode when the meter shorts that terminal to ground. Chances it's well within the limits of the KX3 KEY OUT line (30V, 100ma max). BTW, the S-BOX or S-BOX-USB makes a nice "docking station" / computer interface for a KX2 or KX3, if you need one. Rig control plus computer-generated CW and PTT over a single USB cable can be provided, along with all the required interface cables. https://www.kkn.net/~n6tv/S-BOX/Features.html#KeyingExampleKX3 73, Bob, N6TV https://bit.ly/S-BOX ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
