Poor performance when DCC sound fitted

I decided to add a sound chip to one of my Hornby Railrosd Class 55 locos. Why bother you may ask?  Well I had this plan to upgrade the beast, having already added flush glazing and I happen to have a spare 8 pin sound decoder for a Class 55. Anyway the thing runs OK on DC and with an ordinary Hornby decoder, but when I put the ESU LokSound Decoder in it, it runs really well, except that it kangeroo hops at very slow speeds on start off. Then, when it halts it glides gently to a stop then lurches forward two or three times before coming to rest. The sound works perfectly, although it is a little quiet at the moment. I have tried adusting start voltage but that made no difference. I have also tried it on all speed steps from 14 to 128.

Just to check, I popped the same decoder into a second Railroad class 55 and got exactly the same problem.

Any ideas?

Bob

if your can get a cv chart for decorder your can adjust cvs to get rid off it had same problem with a Bachmann pannier on that I adjust cv 52+ cv 53, david

I have mentioned your problem Bob to Max.

Hi Bob

It sounds like the Speed Table has a couple of CVs which have jumped out of line.



Here's one for one of my locos.  You can see that they all follow each other.  It's a bit of a business doing it without a Lokprogrammer.

Those boxes represent the values of CV's 67 -95.  It can be done manually by reading the value of each CV and plotting it on a graph. 

You will see which one is out of whack and then you can reset it by trial and error.

Or you can find someone with a Lokprogrammer who will do it in a few seconds.

I hope that helps.

Have you tried removing the capacitors from the motor? They can stuff up the BEMF settings a bit.

That's another thing you can try: tweak the BEMF settings to better suit the Hornby mech - they are probaby set to suit a larger can motor and flywheels at the moment.

Good thinking 99.  Capacitors = bad.

Also, try entering 0 into CV 54, then press function button 1.

The loco should shoot forward as the decoder "reads" the motor.

Thanks all for all the suggestions. This is what I have done. I have tried adjusting the CV settings. The first one I tried was CV 63 to increase the volume, which is a very noticable adjustment. It did not change at all. I thought there might be a problem with the controller (Prodigy Advance) but I adjusted the same CV on another loco without problems. I tried changing the SV settings, again no reactions. Yet I was able to change the loco address. I have concluded that there is a fault with the decoder, so I took it back to the shop today to be tested on their test track. Same problems arose, so the shop is going to replace it for me. Sadly they did not have another decoder in stock, so I left the loco and old decoder with them. Hopefully thet will get it sorted.

Bob

Oh bother (or words to that effect).

I don't know what, if any, tests they put these things through before dispatch but it really isn't good news for duff ones to get out to the public.  Imagine you were a Novice (:roll:) who had just dipped your feet into the DCC sound waters.  I think I'd probably say "I thought so - far too complicated for current technology.  I'll stick with clockwork - I know it works !!!" …………

We are customers who pay our hard-earned money for expensive items, not "field testers".  Is it too much to ask that we EXPECT it to work. !!! :twisted::twisted::twisted::twisted:  I'd be expecting some kind of hefty recompense in addition to the replacement decoder Bob.  Tell them it was for someone's birthday and ended up being a bitter disappointment.

A quick update. As mentioned I returned the decoder to the retailer and we tested the loco on his test track using the shop Bachmann Dynamis system. Exactly the same symptoms were observed; namely kangeroo start, very quiet sound (barely audible) and a hop and a skip after the loco has come to a standstill. After some discussion they decided they would take the loco in and do some tests, unfortunately their DCC man was not in the shop that day.

Two days later I got a call to say it was fixed and they offered to post it to me, but I decided to to pop in and see it running on the test track again.

I must say I was surprised as everything was perfect. here is what they did:

1. Put speaker in the supplied sound box (which I had not used), moved the speaker to the front of the loco above the front bogie. I had it under the exhaust exit. (not sure what difference location makes?). However, I noted that the CV setting for CV 63 had been increased to 170. (I did not realise it went that high) Normally I have mine set at around 20?

To sort out the jerky movement he changed two CVs:

CV 55 was set to 5 and CV 54 was set to 54.

The net result is I have a very smooth running Deltic, with excellent sound.

Bob

Now you have your Deltic all sorted out, there is only one more thing to do… Make up some name plates for it - 'Kangaroo' :mrgreen:

Cheers, Gary.

That's a good result Bob. :thumbs

I know some speakers require a "sound box" - whatever that is …………:???::???::???:

Regarding location, it could be resonance within the model depending on the surrounding spaces or, the ability or otherwise, for the sound to escape.

CV's are something to do with job applications - the bigger the number, the more chance of finding employment…………………cheers

[user=878]Gary[/user] wrote:

Now you have your Deltic all sorted out, there is only one more thing to do… Make up some name plates for it - 'Kangaroo' :mrgreen:

Cheers, Gary.

Or skippy!!!

Or skippy!!!

Gotta love that one.:thumbs