Hi all, I have several sets of N scale Con-cor PAs in PA-PB-PA configuration (plus a Con-cor E8 3 unit set). All the A units are powered and the B units are dummies. I am going to use one decoder mounted in the B units to power both motors, I have checked the current draw and it will be ok. I would also like to put sound in them but cost is a huge driver in this, hence sharing decoders in the first place. I am planning on using the Digitrax SDN144PS. Digitrx have a sound scheme on the site that can be downloaded into this decoder for the PA's and E8s. I have done a lot or reading into putting more than one speaker on a decoder and understand the concept of putting two speakers, each with half the impedance of the original, in series to spread the sound without overworking the decoder. I am thinking of putting one speaker in the rear of each A unit (the PA’s will need modifying, the E8 have room). My main question is how to wire the motors. Is it similar to the speakers in that by wiring them in series it will reduce the load on the decoder? Or should I wire them in parallel? (I would have wired them in parallel before reading about the speakers). I may end up just keeping a single speaker in the B units but I have also considered using the HO decoder SDH164D, I believe it is basically the same, but bigger, and has a 32 ohm speaker instead of an 8 ohm. This would give me two 16 ohm speakers instead of two 4 ohm ones which should sound better? Hopefully then with the drawbars I have made and corridor connections concealing the wires these should be great power sets. Any thoughts? Cheers, James
Wiring ( and have it working well) two different motors to a single decoder is not so simple as wiring two speakers in parallel. Consider that the decoder supply a "modulated signal" to the motor coil , also it "read" the current sink from the motor to calculate his BEMF... so having two different mechanics ( two locos) and two different motors connected to the same output, it's not recomended. Also, the sound quality depend more from the speaker diameter and construction, and also on the speaker box insulation.... than from the area covered by two differen speakers. I mean: it not that if you install two speakers = more sound quality. remember also you need to add some contacts from rails on the dummy units. So, my simple suggestion is: leave the Dummy as Dummy but install a sound decore on it, with only one speaker in the Dummy. Then install one no-sound decoder in the "A" unit .... and simply "Consist" both decoders togheter.. take care
Well with the new Kato P42 unit that has dual motors, SoundTraxx web site shows installing a sound decoder into this unit. As I understand there has to be some tweaking of some CVs to get the unit to run smooth. SoundTraxx is going to post the CV settings of the factory installed units soon. This should provide a good base to start with, for the sound installs. If you have a non-sound install I would guess that the CVs of the sound decoder would be a good place to start with on the non-sound decoders.
Thanks for the feedback guys, as I have a Digitrax SDN144PS on the way I am going to try it and see what happens, I can't justify buying another decoder for the other power unit yet anyway. I have read that this has been done by turning off the BEMF? I will post up some pics of the install and let you know how it goes.
Well, conversion done. And the twin motor and 1 decoder works great using a Bachmann chip, I have now added a Digitrax sound decoder and will test it in just over a week. I posted it in the photos etc in a new thread in the N scale forum... http://www.trainboard.com/grapevine/showthread.php?153460-Concor-PA-s-DCC-A-tale-of-two-motors -James
