Yes, you can use a walkaround DC throttle - in fact there are several circuits in the files section of the Digitrax Yahoo Group for simple ones that involve a 9V battery, a DPDT toggle, a potentiometer, and a transistor. Super simple, and you cna get all the parts at Radio Shack.
No, you cannot unplug it, the train will stop. If you already have a fancy DC walkaround system that does allow for unplugging the controller, you can hook the output of that to the jump port and it would allow unplugging - however it would be foolish to spend the money on something like that, you'd be better off buying a UT4 throttle which you can plug and unplug at will AND since it's a Digitrax throttle you can select loco addresses and operate functions from it. Jump throttles basically only allow you to control speed and direction, although you can toggle the Zephyr keypad to allow function commands to be sent to whichever loco it on a given jump throttle.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
yes, i don't think you can use any DC throttle with feedback/ BEMF, it has to be a plain DC output. but the zephyr has no idea if the DC it is getting comes from a walk around or fixed controller, or even a battery?? what i don't know is IF you unplug the DC supply to the jump port, does the train keep going allowing you to relocate with the walk around throttle like you could with say the DT400, but i would think not as unplugging it would be the same as setting the controller to zero to stop the train.