gahorn wrote:Regarding the rheostat (an Ohmite product). This item is actually nothing more than a wire-wound resistor with a carbon-brush which is slid along the wire windings to select the amount of resistance desired (resulting in the appropriate amount of brilliance from the lighting.) There are 3 terminals. The center one connects to the brush which is controlled by the knob. The end terminals connect to each end of the wire windings. Depending upon which way you want the knob to turn increasing brilliance, determines which of those terminals is used. The other end is left as an open circuit.
Twiddling my thumbs one day, it occurred to me that the only way the lights are extinguished is due to the overwhelming amount of resistance found at the far end of the windings. In other words, electricity still flows through all those bulbs and the rheostat even when the lamps appear not to be glowing. It's a minor thing, and probably not important, but it just drove me nuts.
So I did an unauthorized modification to my rheostat. I mixed up a small blob of epoxy and, with the brush moved to the far end of the winding, ...I put a very small, thin, smoothly contoured dab of epoxy on the opposite end, where the terminal is crimped upon the resistance wire winding. After it hardened, it provided a nice little resting place for the brush to reside that completely interrupts the electrical circuit. In other words, it provides a true "off" position on the rheostat. ***
As a follow up to this thread, I just rec'd a call from a member looking to replace/repair his rheostat and wanting to know how to obtain one without paying Cessna $250 and his first-born male child for it.
The rheostat is mfr'd by Ohmite Mfg. Co., Skokie, Ill 60076 (A North American Phillips Co.) and is their model "H", 100 ohms, 25 watt, stock no. 0151. You might find them locally at electronic/electric supply houses, costing typically between $2.50 and $20 depending upon markup. ( I once purchased several at a surplus electronics supply house for 25 cents each, but they've all been utilized and/or given away now...sorry.)
A similar, though smaller and less wide control capacity, rheostat is available from Spruce, their pn 0144, 25 watt, 8 ohm, for $26.50.
If you're a REAL frugal person, you might find that if your rheostat has failed to either full ON or full OFF (with no dimming controllability) that you can still save your existing rheostat by simply removing the wire connection from one end of the wire-wound resistance wire terminal, ...and resoldering the wire to the OPPOSITE end terminal. This might be due to the resistance wire having broken at the terminal end being previously used....while at the opposite end still being serviceable. The only downside is that the knob will rotate in the opposite direction than previously when dimming/increasing lamp brilliance. (This may not work quite as satisfactorily if you've modified it with epoxy as mentioned previously, however.)
That's a polished prop? 
