After working on configuring my Elecraft K2 for remote operation. I am finally on-the-air. I had been using it in receive-only mode while I completed a “dead-man” timer, that would shutdown the transmitter if I ever lose my Internet connection while in transmit mode. This is required by the FCC.
It turns out, that remote use is another reason that it is good to build the K2 in one chassis and the 100 watt amp in another. It is perfectly safe to disconnect the power to the base (QRP) K2 with a timer. This avoids the need to interrupt the high-current connection to the 100 watt amp. I was assured that this is safe by Elecraft guru Don, W3FPR. If you ever ask a techical question (especially troubleshooting), Don is likely to give you the answer. Here is what he had to say about this (posted with permission – thanks Don):
Yes, it is sufficient to kill the power to the base K2 (when the KPA100 is mounted remotely). Unlike the K3, there is little to be lost (bits mixed up) if you turn the power source off for the K2 during normal operation.
——— And he went on to say in another message ——-
If the base K2 and the KPA100 are mounted in the same box, then the situation is different – you would have to interrupt the higher current connection (to the KPA100) if everything were connected normally.
Now, there “is a way” — if you do not connect the AUX 12V connector from the KPA100 to the base K2, the base K2 will not be powered by the KPA100 power supply connection – you will have to power the base K2 from the coaxial connector. That makes the power off conditions the same as with the remotely mounted KPA100.