Elecraft KAT500 Serial Command Reference - Manual (Page 5)

SET format: AKIP wwww;
GETs or SETs a transmit power threshold below which the KAT500 can interrupt the amplifier key line.
The KAT500 must interrupt the amplifier key line before it changes other relays during Memory Recall or
Full Search Tune: bypass, antenna, capacitors, and inductors.
Some amplifiers, such as the Elecraft KPA500, use solid-state transmit/receive switching devices that are
designed to permit the amplifier key line to be interrupted while transmitting. For the KPA500, the AKIP
threshold should preferably be set to its “unlimited” value: 1500 watts (AKIP 1500;). Use 1500 even if
the amplifier is incapable of supplying that much power.
Some amplifiers, such as my Ameritron AL-1200, use a frame relay and “hot switching” the amplifier key
line with high transmit power might damage the relay. I use 100 watts (AKIP 100;), which is enough to
pass all the unamplified power of my K3, but lower than the power I’d expect with the amplifier in
“operate”.
The default “factory” value for this threshold is 30. If you are using an Elecraft KPA500, you should
increase this value to 1500.
The RESPONSE format shows the power in watts, and the VFWD threshold that is used to monitor this
threshold.
While the transmitter power exceeds this threshold, some KAT500 front panel button presses are
ignored, as are serial commands (and KAT500 Utility functions) that change relays: MD, AN, BYP, C, L,
SIDE, etc.
TUNE may be started with a higher transmitter power, but power must drop below this threshold before
TUNE interrupts the amplifier key line. Tune-level power must be applied again to complete the tuning
process. After tuning, transmit power must be reduced to zero before the amplifier key interrupt relay is
released, unless the “unlimited” value 1500 watts is used.
AKIP was added in firmware version 01.05, and is used by the KAT500 Utility Edit Configuration dialog
Amplifier Key Interrupt Power tab.
AMPI (Interrupt amplifier key, GET and SET)
GET format: AMPI;
SET/RESPONSE format: AMPI0; (amplifier key line connected), AMPI1; (amplifier key line interrupted).
GETs or SETs the amplifier key line interrupt relay, K23. AMPI1; selects the relay, interrupting the
amplifier key line. AMPI0; releases the relay, connecting the amplifier key line.
The amplifier key line must be run through the KAT500’s amplifier key line interrupt relay.