You and me both. This is a common problem with homebrewed rigs. Ham homebrewers don't like to draw schematics apparently. I can guess why: After all the work, they probably figure you got the rig and it works, therefore I am DONE. If I were paying someone to build a rig for me I'd insist on a schematic as part of the deal. I've heard hams say, "Well just ask me if there's a problem." Well, as you and I know, someday, someone will get a nice HB rig and the builder is SK and we are left looking at some part or circuit wondering...."what does that thing do?" You all might think it's a plate modulated AM rig and who needs a schematic for that. Well, once you get an old rig built into a rack with wiring harnesses going every which way, and all the wire is the same color jacket, and it's full of mystery relays, keying circuits that don't make sense, stuff that's been changed by previous owners and so on, you'll wish you had a schematic. Message to hams who homebrew rigs: You may be making it for yourself, but you won't be around forever and someday someone will get your work. Do them a favor and draw up a schematic and tape it to the inside of the rack.