Is there a simple way to find the location in a B unit where a sound only decoder could pick up track power? I was thinking that my multi-meter set to the continuity reading was the place to start.
If it is powered, it would be easy. You would just need to solder the pickup wires the metal tabs on the powered truck.
If it is an unpowered dummy, then it might be a little tricky.
Place the unit with the shell off on the track with the power on. Set the multimeter to AC and find out where you are picking up power.
Will
It is unpowered (Stewart) and the truck assembly is plastic except for the metal wheels. I did a slight variation of the test you suggested and there does not appear to be any point on the unit other than the wheels that establishes an electrical path from the track.
Does this mean a wiper to each wheel that is soldered to the frame/weight and then attach the decoder wires to the frame as well?
mreagantDoes this mean a wiper to each wheel that is soldered to the frame/weight and then attach the decoder wires to the frame as well?
Pretty much.
Stewart dummy B units have all the bits of the powered units minus the gears in the trucks, at least my F7 B did. I just soldered wires to each of the metal truck sideplates and had 8 wheel pickup for what was going to be a sound installation with multiple speakers, like one that Bruce at Litchfield once had pictures on his site. Two large bass speakers with a crossover and a small tweeter. If you look at the exploded views on the instruction sheet and see where the wires attach for the powered units - same place should have power in the dummy.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Ditto Randy's answer. All of my dummy Stewart units had the metal plates in the trucks. All I had to do was solder a wire onto it.
Looks like I'm not in luck with that. Truck side frames on my F7B and my FTB are plastic. I am going to check to see if the draw bar on the FTs is metal since that might solve that problem. Otherwise, back to the drawing board.
mreagantTruck side frames on my F7B and my FTB are plastic.