On Monday

     It looks like I'll need to go in early next Monday: the last pieces will be arriving for the replacement for a major device that has been an albatross around my neck for most of the past fifteen years.

     It's a transmitter.  The one on the air has to run at full throttle -- and a little more -- to make 100% power. When it first went on, the assigned power was lower, and it was plenty big.  The company lawyers went to work and got the numbers raised, hooray!  But it would barely achieve them.  No worries -- we'd built the "new" digital transmitter from bits and bobs of a massive solid-state analog transmitter and there was a lot left over: we had only used three of the seven big power amplifiers (call it ten thousand Watts per each).  Of course, it would need a few more parts from the manufacturer to add a couple more back in, and some of those parts were very expensive.  As in capital budget level: your department's got to put in for it in advance, and make a good case for it, and....

     Transmitters might be a critical component in my line of work, but unless they go badly wrong, they're invisible -- almost literally; years go by when the Facilities supervisor and I are the only people who visit ours.  Engineering's capital budget includes all the big, shiny, fancy technology, and all that stuff chases the technology curve, especially since everything went digital.  It requires frequent replacement.  Budgets enter the process deliberately inflated: the Corporate accountants will cut.

     The parts to make the transmitter more powerful kept getting cut from the budget.  Wasn't it working well enough now?

     It reached the point where it required constant adjustment, almost like the old vacuum-tube transmitters.  The power transistors it uses have a correlation between gain and temperature that is very steep, and unless there's plenty of power in reserve, the output varies significantly with room temperature; since it is air-cooled, in a "closed-loop" system, and the amount of excess heat it produces depends on power output, it forms an unstable system with the air-conditioning, as heat load and cooling capacity chase after each other.  At 60 to 65°F, it's about as stable as it gets, but that's not a great operating point for the cooling units: they tend to freeze up.  And things got worse.  There are "MMICs," monolithic microwave integrated circuits, in the RF signal path, and early ones tended to suffer "gain fade" over time: very slowly, they produce less output for a given input, and eventually, it won't go as high as it used to.  The early ones aren't being made any more; I can't just screw a new one in the socket like replacing a light bulb.

     It was time to add those extra amplifiers back.  Every year, I'd been getting a new quote; every year, my department head had been putting it in budget requests, and every year, shinier and more urgent things had crowded it out.  I went to the manufacturer to update the quote.  Too late.  "Oh, that equipment's not made any more.  We still stock repair parts, but the big items you need are no longer available."

     My employer replaced the cooling system; I came up with ways to scrape every last bit of reserve gain left, and finally got the transmitter back into a stable operating range.  But it is a precarious balance, and the next big decline, or the one after it, will be the last.

     We've got a replacement.  It's not brand-new; ongoing shuffling-around freed up a transmitter only a year old, retunable to our range.  I've had most of it for months.  The parts that need to be retuned, critical items of some size, are scheduled to arrive Monday.

     Installation has yet to be scheduled, but expectations are it will be some time this year.  Once it's up and running, I'll look less essential to the accountants, but having a transmitter that isn't straining to make power will be a big relief.