[Elecraft] Extra Protection For KPA500?

[Andy Durbin]

"Well there is one exception to the idiot-proofing and that occurrs if you use macros that have the PCxxx command in them for setting power.  Under certain conditions if a PCxxx command is used in a macro it can overide the CONFIG:PWR SET Per bAnd setting.  I have removed all PCxxx commands from my macros until I understand this completely and have tested each macro."

That vulnerability probably also exists for a power command sent by an external application.

An external controller can never be as fast as the AUX Bus link but it can react fairly quickly.  In this example I forced my TS-590S to well above the coded band max power limit using DXLab Commander.  My controller disabled the KAT500 key line, forced my TS-590 back to band power limit and,  when band limit power was confirmed, my controller re-enabled the key line.   (time with 1 ms resolution is elapsed time since controller reset)

54:03:44.949  New PC - PC075;    << controller sees increased power setting of 75 W
54:03:44.951  Power protection activated
54:03:44.953  band power limit exceeded
54:03:44.954  Sending AMPI1; to KAT500  <<   KAT500 is commanded to inhibit the key line
54:03:45.022  Sending PC030;AN999; to Kenwood   << TS-590 is commanded back to band power limit
54:03:45.036  New AMPI  - AMPI1;  << KAT500 confirms key line is inhibited
54:03:45.266  New PC - PC030; << TS-590 reports band limit power is set
54:03:45.268  Power protection cleared
54:03:45.269  Sending AMPI0; to KAT500  <<  KAT500 is commanded to re-enable the key line
54:03:45.512  New AMPI  - AMPI0; <<  KAT500 confirms key line is enabled

Would it have prevented a KPA500 fault if I had been transmitting, I don't know.  I try to avoid tests that are potentially damaging to my equipment.  I do know that my controller caught the error and fixed it far faster than I could have done.

73,
Andy, k3wyc