PACman

I have a Bachmann Class 108 DMU, green with speed whiskers, that was sold as a 2-car DMU but in a box for a 3-car. I would like to get hold of the missing centre car. So, looking for anyone who might have a centre car for sale, Bachmann and green with yellow lining.

Well I have been on the Bachmann website and their documentation for the 36-557 is daunting to say the least... a 37 page User Guide and a 57 page Technical Guide for a decoder may be comprehensive, but doesn't help the novice in knowing what can/should be changed!! Strangely, the guides are named as 36-558 and not 36-557, so I am not sure if I am looking at the right thing at all. What is desperately required is a single page reference sheet on basic CV settings to make a loco work (e.g. CV settings for Small Steam, Large Steam, Shunting Loco, Diesel Loco etc.). If people wish to fine tune them afterwards then they can, but at least the majority of users can get their locos working then. Perhaps Soundtraxx and/or Bachmann can provide here? Paul.

Thanks Suzie, you are right. However, there does not seem to be anything equivalent to the CV 54,55 to control the back EMF effect; instead there seems to be a wealth of "Advanced Motor Controls" which I think I need a PhD to understand. Has anyone any experience of using these new 36-557 21 pin decoders? They are a very different beast from the 36-554 decoders they are supposed to be replacing, and programming them seems very alien to working with previous Bachmann and Hornby decoders. Paul.

Hi guys, just picking up on this thread again... I have just fitted a Bachmann 36-554 3 function decoder to a new Hornby B1 and made the adjustments noted previously to CV 54, 55 and 29 and it has made a big difference to its slow speed performance, however it is still a little rough at a crawling pace, despite the B1 having one of Hornby's 5-Pole motors fitted. Is there any other adjustments I can make to slow speed running other than CVs 54 and 55? More challenging is the use of the new 36-557 4 function 21 pin decoders; I have fitted one to each of a Bachmann G2A and SDJR 7F. On either loco I am unable to read back CV values for CV 54 or 55, each just reporting back a value of 255. Also worryingly, the G2A when placed on the Main Bus will creep forward without any command to move having been issued; might this be anything to do with me having removed all the capacitors and resistors and having now attached the decoder wires direct to the motor? Are there different CV values that should be used for the new 36-557 decoders? I have been successful in setting the loco address for each, but I don't seem to be able to read CV 54 and 55, so cant tell what values they are being set to (indeed if they are receiving the programming at all!). Any help gratefully received. Paul. BTW I use the Hornby Elite running v1.41 firmware.

Hi Mike, My layout is fully wired using R8247 accessory decoders already, operating all the pointwork. I was considering using some of the spare ports to run the lights and perhaps the odd semaphore signal, so this is probably not an option. I would be interested if anyone has experience of switching DC lighting circuits using latching relays powered from the R8247 outputs...on the face of it, it doesn't look that difficult (famous last words) Paul.

Thanks Guys, Ian, this has confirmed my suspicion that the Accessory Decoder, whilst good at sending a short high power burst from the Capacitor Discharge Unit (CDU), is not much good for continuous operation; so the relays will be the answer. I guess I need to have a trawl of the Radio Spares (RS) Catalogue and see what is involved in making up a small circuit board of relay units to drive various lighting circuits. Harold, what is the transformer you use to drive your lights? I think I will need one of these to power the lights through each relay. Cheers, Paul.

Guys, just read this thread. Does anyone know how much current can be drawn through the each port of the R8247 in continuous mode? I understand the output provides 15vDC but I presume there is a limit on the wattage of the device you can attach. I am thinking of operating some Kytes Lights platform lights, and perhaps some semaphore signal operations, and need to know what the limitations are. Am I more likely to require some kind of relay rather than running the lamps directly through the decoder outputs? Any ideas? Paul.