Oops I clogged the Space Station Toilet

Aerial view of a broadcast tower with "HHHHHHH" emanating from the transmitter building.
HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH

Down in the river delta this morning, a circuit breaker went TWANG, and eventually, an engineer went HHHHHHHHHHHHHHHHHHHHHHHHHHHH.

The Space Station Toilet transmitter dumped one cabinet. While I was waiting for one of my coworkers to get there on site and see why it wouldn’t come back up, the first order of business was to remote in and change the combiner mode so the dead cabinet was no longer in the system (which caused a large amount of power from the other two surviving cabinets to get dumped into the combiner reject load due to the mismatch).

 

The Space Station Toilet is an older generation of Harris transmitter using their old eCDI user interface system. Their newer stuff uses a weird looking but far easier to use interface which does not require FECKING JAVA (!!!!) and has a nice block diagram sort of layout. You can see it in action here on a HPX series FM. Since it’s natively designed to work great on touchscreens, the newer GatesAir TV rigs come with a cute little pull out shelf where you just set a generic tablet PC in there to use as the front panel UI. But uh, eCDI is a confusing dated looking mess, and its design contributed to an… incident.

I went in there, took the dud cabinet out of the combiner on the mode tab, then noticed cabinet 1 had no IPA power or beam voltage. I decided since it was not working correctly to switch it back to BG heat until it could be serviced.

BG heat is kind of a keep warm mode that leaves the ESCIOT tube filament on at reduced voltage, and I think also leaves the ion pump on. It’s basically a warm standby that keeps the filament ready to go, and helps maintain the hard vacuum while the tube isn’t actively online. Well….

 

Two minutes later I got a call from our director saying “hey, we’re off the air, and I think it’s because you did the same thing I did…”

Sure enough… Note the two screenshots. See the difference?

Blink and you miss it. It’s not the difference of which button is selected at upper right.

The issue is, if you’re in the HPA tab at the bottom, the Beam On / Standby / BG Heat / Off buttons affect the state of one HPA cabinet, as selected by the 1/2/3 buttons. If you’re in the TX tab, guess what they affect the state of….

KERPLUNK. FLUSH. BEAM OFF. ZERO WATTS. ENJOY BUSH’S BAKED BEANS.

Beans. Mmmm, beans.

The day this thing is to be decommissioned I want to see what happens if I fill the cooling system and high voltage power supply cabinets with beans and turn the transmitter on one final time. BEANS ON, BABY! Mwahahahaha.

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