[Elecraft] External amplifier with QRP version of the K2

[Chuck Guenther]

For a few days now, I've been driving my Ameritron AL80B amplifier with 10-15 watts from my K2, yielding roughly 100-150 watts output on CW (no QSK).  It's been working very well.  I thought I'd share how this is implemented, in case anyone else is interested. 

I have three rigs (Omni 6, K2 and Sierra) antenna outputs routed through the amplifier relay contacts using an MFJ 1700C antenna/transmitter switch.  I use an external keyer (K1EL WinKey) which gets switched to the proper rig with a NCS-3240 Multi-Switcher.  (The multi-switcher unit also routes audio outputs of the three rigs through an external audio filter/amplifier)   The amplifier gets keyed, not by the rig, but by the PTT output of the K1EL keyer, which I have programmed for appropriate lead-in and tail delays to avoid "hot-switching" of the amplifier relay.   

The multi-switcher unit and antenna switch have also allowed me to do quick A/B comparisons between the K2 and my Omni 6.

One of these days, I'll try the KPA-100, but for now I'm able to enjoy the K2 at the "standard" 100 watt power level with what I have in the shack. (No, I haven't tried driving the amplifier with the Sierra !)  

73,
Chuck  NI0C
K2 s/n 5853