Hello,
I recently aquired a control master 20, made by MRC. my question is how do
I wire the telephone jacks to the unit itself? Also what is the purpose of the
nudge switch?
Thanx in advance for any replys.[:D]
Hi Dave,
I have several of the CM-20s. They’ve given me good service.
Everything you need to wire a CM-20 system is available at your local home improvement store or Radio Shack. I have two cabs, so I use a dual wall jack for each place around the layout where I need to plug in a controller. The top jack is my A cab and the bottom is my B cab.
Remember to design your system so that no controller is a total of more than 40 feet by wire from the CM-20 itself. This includes the coiled cord length for the controller, which is supplied with a 15 foot cord. Thus, your longest run of cable can be no more than 25 feet in addition to the coiled cable supplied with the controller…
I use 4-wire telephone hookup cable from the wall jacks, which are installed in my fascia, back to the CM-20. This wire then goes to a terminal jack. It has connections for each of the four wires, as well as a short pigtail terminated with a standard phone jack. This is then plugged into the phone jack on the fornt of the CM-20.
Also note that you can plug the controller itself directly into the CM-20. Essentially, the rest of your wiring is much like running phone jacks to other rooms in your house. Together with the memory feature of the CM-20, this allows you to unplug and move your controller to plug into the next jack to follow your train as it continues to move.
A note of caution is that MRC redesigned the CM-20 circuitry somewhere around 2000. Controllers for the earlier version do NOT work with the updated version, so do not try to mix and match between the two versions. The newer controllers ar marked as “Version 2” in small white print on the back of the controller.
The manual claims that enabling NUDGE allows better low-speed operation. I can’t tell much difference myself with the locos I have, but the expereince of others may differ.
It sounds as if you may not have the manual for this unit. It is available online from MRC at:
ht
I phoned MRC about the ‘nudge’ switch when I got my Controlmaster 20 (which I really LIKE, by the way) and it comes in very handy if you’re running locos with sound, such as BLI, as it gives you a lot more quadrant control on those particular locomotives. Also, if you happen to have any older locomotives with Pittman open-frame motors, the ‘nudge’ makes for much smoother low-speed operations. With normal ‘can’ motors, you can’t tell the difference. But it’s one HONEY of a power-pack! My only problem is that a 25-foot extended COILED telephone cord doesn’t seem to want to work with the controller, however a STRAIGHT 25’ telephone cord works just perfectly. Just remember to carry the cord around with you when you’re running the trains, as those straight cords find every nook and cranny in your benchwork to get hung up on.
Tom [:D]
We use CM20s at the the club…We have use these since the early 90s without any problems.Since our layout is a walk around point to point we use 4-wire telephone hookup cable with wall jacks.The throttle plug ins is located every 12’ around the layout-to give you some idea our main line is 1,482’ long…We also use CM20s for our freight yards,passenger terminals and engine service area.
Hey Mike, thanx for the link to the manual, I printed out for future reference.
Also thanx to Brakie & twhite for your replies.