Many thanks to SWLing Post contributor, Paul Walker, who writes:

If you know any DXers out in western US… pass the word:

Saturday night/Sunday Morning, at 12 AM Pacific KKOH 780 will be off the air for about 6 hours to do some maintenance.

Thanks to Chief Engineer Daniel Appellof for letting me know well ahead of time so I can pass the word

[…]Listen after the off air time is done because KKOH will come back on at 50KW non directional and will have 10-30 minutes of dx test material…. sweep tones, morse code, telephone dial tones and telephone off hook noises and such.

[UPDATE] We’re going to get about 15 to 20 minutes of DX Test material at 50kw non-directional tonight at 12 midnight before he shuts it off.

Thanks for the tip, Paul.  I’m sure west coast US DXers will certainly enjoy this opportunity!