Was hoping someone could help me out with a better understanding of how Williams went about naming their SA and SG Coils used back in their early solid state days.
For my example, I'll use the machine I'm working on: a Williams Scorpion.
This machine, flippers aside, uses 4 coil part numbers exclusively:
I've read a ton of sites, pinball medic's coil reference, etc and I can honestly say that nowhere have I found anyone that actually directly explains what the first portion of the part number actually means. 23 is the AWG and 850 is the number of turns of the coil wire and DC is self explanatory. But what is the actual difference between SA, SA2, SA3 and SG?
From trying to piece together random bits of information I've gathered from many sites (and the fact that when I ordered some SA3-23-850-DC's from Marco, they sent me SA-23-850-DC's instead, with a specific coil sleeve), I believe that these might actually all be the EXACT same coil (with a different wrapper), but that the true differences are:
1. SA and SG are the same, but the A or G denote the direction the sleeve is supposed to be inserted into the coil.
2. The "2" or "3" (or the lack of a number) simply denotes the length and type of sleeve that should be used. For example, and SA3 would used a flanged 2 11/16" sleeve (per the kit Marco sent me), and would be exactly the same as an SG3, but with the sleeve reversed. This would make sense, since the old manuals for the machines that used these coils didn't have info about the coil sleeves that should be used, so maybe this was how they did it..... By "writing" it on the coil and in the manual in this cryptic way.
Can anyone who knows the actual answer here either validate my assumptions or set me straight on exactly what the prefix truly does mean for these type of coils?