[Rovernet] SD1 Rover brake servo compatibility

[Glen R Wilson]

On 12/7/20 2:52 PM, geffandjulie--- via Rovernet wrote:
> Super Sabres

...And Geezer talk...

Geoff,

That's impressive. The F-100 was a beautiful beast, but I gather they 
could be tricky to fly with some quirks that could catch you out without 
warning. You must have been good or careful or lucky or all three.

I bought a new house recently that was built in 1900 and has a number of 
interesting original bits still attached like a pocket door and an 
ingeniously basic toilet paper holder in the basement water closet. When 
raking the leaves behind the garage, I came up with a vacuum tube that 
appeared to be from a tv. When I went to work for GE Medical Systems in 
1982, they gave us all those orange vacuum tube cases with the hinged 
tops the tv repair guys always carried just to store our spare parts in. 
There were still some things that only vacuum tubes could handle in 
1982, and there were a couple of really old systems still out there in 
the weeds. There was one that had some kind of Kemtron vacuum tube as a 
rectifier in the high voltage transformer tank. Part of the 
troubleshooting routine was to take the cover off and check to see if 
the filaments were glowing. They were a weird red color like burning embers.

Of course, x-ray tubes (where the x-rays come from) are still vacuum 
tubes which have been refined over the years but have not really changed 
in their fundamental design. I was at the dentist the other day, and 
could see the x-ray tube filament glowing orange when they took the 
x-rays. You wont see that in a standard x-ray tube in a hospital because 
there are aluminum filters between the patient and the tube filament. At 
higher KVPs the aluminum filters out radiation that would contribute to 
radiation dosage without yielding diagnostic information and also reduce 
the image quality. Dental x-rays are such low dose and KVP that the 
filtration is not necessary. Last bit of vacuum tube rambling is that we 
used to have vacuum tubes a little smaller than a gallon of milk that 
were tetrodes with a massive copper base. They were used for high speed 
switching of the voltages going to the x-ray tube in cardiac 
catheterization laboratories. When they went bad the whole department 
stopped. Through a paperwork error, I ended up with a spare I carried 
around in my trunk so that I didn't have to wait for one to be 
overnighted in. They were a $10,000 item, so they weren't just laying 
around. Made me a hero several times with the customers, but had to be 
careful the bean counters didn't know I had one.

Just Geezer rambling...