I have been working on a few electronic projects in my new found spare time and have designed a nifty little circuit to "kick" the E unit with DC instead of AC. Since it is the AC on the e unit's coil that causes some Lionel operators to gnash their teeth(and some don't mind the nostalgic noise) the solution is to kick the e unit with DC. Ahhh, but you say the DC will overheat the coil and magnetize it. My solution solves both of these quirks. The motor still runs on the track AC voltage.
First, I built a 1 second 555 timer circuit and the pin#3 output is used to energize a little DPDT 5 volt DC relay. The common and normally open contacts of this relay are used to send a 5 volt DC pulse(1 second long) to the E unit. Therefore, the E unit only see 5 volts DC for one second each time it is asked to rotate the drum. Yes, you do need to modify the E unit but I can make that explanation easy if you want to try it.
If anyone would like to see the circuit, I will post it if I can figure out how to put a CAD drawing on this thread.
Before you say yes please post, understand that this is an electronic circuit based on a 555 time which needs 5 volts DC to work....full wave bridge and a 5 volt regulator is part of the design.