I purchased a used post war Accucraft (American Main Line) K-4 Pacific and recently installed the new Phoenix PB9 "Big Sound" system in it. This is the updated replacement for the 2K2 system. The results are very disappointing. At low speed I get the 4 chuffs per driver rotation but as the speed picks up it begins to skip and at anything approaching normal operating speed the sound cuts out and in fact seems to finally shut down resulting in a short whistle toot like the train has come to a stop. When the speed is slowed down the chuff comes back again. I am not sure where to start trouble shooting here- locomotive problem? - Phoenix sound problem? Has anyone had any similar experiences and solution ideas?
Tom
Tom,
The problem may not be the P9. I have a K-4 and had similiar problems with both QSI and Phoenix. What I found out was that the wire brushes on the sound drum were apparantly bouncing as the engine sped up. Ultimately, I put two magnets on a driver and used a reed switch for picking up the chuff. For video of the results, go to youtube and do a search for "pimanjc." There are several [out of 29 videos] that show the K-4. A few of the videos had a QSI installed. Later, the phoenix and a Trackside TE were installed. The reed/magnets fix was done with the sound card change. Especially look at the "Marty's" videos, when the Phoenix was used.
I hope this helps. JimC.
I have a K4 also, and had same problems with a QSI decoder as JC did. The design of the metal contacts on the chuff drum makes them bounce. Some decoders handle this better and "debounce" the contacts, I have a Zimo in it now and it does a better job, but still not great.
I may put magnets in the drum and use a hall effect sensor.
Regards, Greg
Visit my site: http://www.elmassian.com - lots of tips on locos, rolling stock and more.
Click here for Greg's web site
Jim: Thanks for your reply. Would you be able to discribe the magnets and reed switch that you used and just where you located them? I have not checked the youtube site yet as you suggested but will do that to see if I get a better understanding of how to do this.
Greg: I have seen your website and articles on the K-4 so you definitely have some knowledge of them. I would like to know details of the method you mentioned to improve this chuff function.
My question to both of you is - does the chuff sensor in the loco control the overall function of the Phoenix sound system? I ask this because it seems that when the loco picks up speed to the point where I loose the chuff all together, the sound system seems to think that the train is coming to a stop and it will go through the slow down and stop sound functions including the single whistle toot.
BTW - I tried to increase the pressure of the two contact wires on the sound (chuff) drum and it seemed to make things worse!
The problems with the chuff drum can definitely cause the problems you describe, and that I also experenced. I will try to take a picture of the reed/magnets in the next couple of days. I used the existing wires to the drum to connect to the ends of the reed switch, so I didn't have to rewire or add another plug between loco and tender.
JimC.
Right now I am using BEMF chuff with a Zimo decoder. I am intending to replace the brass strips in the chuff "drum" with magnets, and then use a hall effect sensor (solid state magnetic switch) to trigger stuff.
The problem with the Phoenix is when there is a erratic or "too fast" chuff signal, it gets "lost". Other, more modern designs cope with this better, but it's still a basic problem because of electrical noise.
Since the chuff drum is large, putting 4 magnets in it and using a reed switch should be pretty easy.
I've had the same problems with Bachmann Spectrum 2-8-0 Consolidations. The electrical contacts on the rear axle that are supposed to trigger the sound are very poorly designed, which results in sporadic chuffing.
The cure, as others have said, is to use magnets and a reed or Hall effect switch.
When I purchased my Phoenix sound system, the magnets and reed switch were included in the package.
The Phoenix reed switch and two magnets [mounted on driver at 180 degrees] were glued to the K-4. The wires from the reed switch were attached to the original drum pickup wiring at the screws that held the spring contacts [under rear truck mount].
See attached picture.
Hope this helps.
Jim: Thanks for the detail. Why two magnets instead of four? I assume that the loco would have four chuffs per revolution - correct?
I installed two magnets and programmed the Phoenix to double the chufs per magnet. It would have been difficult to accurately space four magnets.
SFC: Thanks for the comments. I have stainless steel track and have only wiped it with a sponge to clean. Are you running with brass or stainless rail? Your point is interesting bcause just today we changed the chuff sense on the Phoenix to sense when the circuit is open ( phospher bronze wires touching the insulated portion of the chuff cam) rather than when it is closed (touching the 4 brass rotating contacts). This was recommended by both Phoenix and Accucraft when I called them. It helps eliminate the bounce problem of the wires. This solution worked wonders while testing on a set of stationary rollers with chuff speeds able to reach high speeds. Still when I went out to the yard to test on the track, the same loss of chuff and shutdown occured. What would be a good way to clean stainless track?
I have 100% brass LGB track. I also use one of the LGB cleaning blocks when I hear my sound starting to break up, not just when an engine has power problems. It takes a little time and muscle but it is worth it. I don't know what should be used for stainless, but try the LGB block, maybe it works. Stay away from anything that might contain metal fillings though or anything that would roughen the track (that would cause shorts and atract more dirt). By the way, do you use metal wheels on your rolling stock? They acually keep the track cleaner than plastic and I like the clickety clack sound.
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