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Hornby TTS Class 66 problem


Leon
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Hi guys,

 

looking for some help, I decided to give the Hornby TTS sound decoder a go for me Bachmann Class 66. The loco runs fine on DCC. I fitted the new decoder with the speaker already attached, programmed the new one on the service track and all went well. Was impressed with the sound for the price.

 

problem now is I get no more sound, the loco runs on the rolling road and all the lights work, I have checked the wires and nothing has come away including the speaker. Not even a crackle now.

 

Could I have some how blow, broken the speaker ? I assume the chip is fine as the lights and wheels work. I have used a 8-21 converter by Bachmann.

 

I dont want to replace the speaker just yet if there is another way of finding the fault ? 

 

Really disappointed, didn't even get chance to put the shell back on :(

 

Many thanks.

 

Leon

 

 

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Hi Leon

Silly question I know but it's always best to rule them out first

Could you have accidentally turned the sound off ?

I normally find with me that faults are due to PICNIC...problem in chair not in computer.

Are you able to try it in another locomotive ?

Have you tried a chip reset to default values ?

 

Chris

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Hi Chris, 

 

 

Thanks for the reply, 

 

When you say sound off, the switch under the loco is still on, is that sound or lights ? Other than that i don't think so, I've been toggling the F1 on and off which is the sound as on my other loco's. (Is there another way ?)

 

I will look now and try another loco.

 

Not sure if related but a few weeks ago a more expensive chip stopped working in a Bachmann class 37 of mine which had been fine for sometime. That was when on the layout not a service track.

 

The chip had been in the class 66 no more than five min and worked great the 1st time i recorded a video.

 

I will read the instructions also to see about a reset.

 

Im using Bachmann Dynamis.

 

Been building  my layout South Wales Freight a good few years now but still pretty new to DCC sound and electrics.  Really looking to concentrate on fitting my ten plus fleet all with sound now.

 

Many thanks

 

 

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6 minutes ago, RAF96 said:

Writing value 5 to CV8 will reset just the sound side to avoid messing up any motor side settings you have made.

Rob

Hi Rob.

 

Thanks, I just tried that. i looked like it was set to 0 so i set it to 5 but still no joy. The decoder did seem to make a quiet nudge sort of noise then pressing the F1 sound on.

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Contact Hornby Tech by phone and explain the issue to them.

I had a problem with a steam loco TTS recently and after speaking to Hornby I obtained a replacement via the supplier and all is well now.

My original problem is described here:

Eight of my loco's are fitted with TTS decoders and they all perform well, I would not hesitate to fit further TTS decoders.

 

Bill.

 

Edited by Bill37
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Thanks Bill.

 

I was going to call them today.  I was happy with the price and sound so was disappointed on my first one, but after what you have said about them I will give them another go.

 

Many thanks

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Hi

 

When you installed the decoder, did you insulate it, TTS decoders get hot under normal use and don't like being wrapped in tape to insulate them, they will blow the sound section very quickly if wrapped in tape or heat shrink.  With my first one I used a bit of loose fitting un-shrunk heat shrink, when I had a look after it failed the heat shrink had shrunk, it had got that hot.

 

Also one other bit of advice I was given is install a resistor in the blue wire as the lighting circuit has quite a low amperage and can also be blown by too many lights being attached and the Bachmann 66 has quite a few lights.

 

I think I just stuck in a 1k resistor.

 

Paul

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23 hours ago, paftrain said:

I know this won’t help you, but I am interested to find out if you resolve your problem as I have purchased the Hornby 66 TTS chip to fit in my Bachmann/NRM model.

 

Hi Paul, 

 

Will keep you updated. 

 

 

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Hi all,

 

Many thanks for taking the time to reply, apologies for posting I know there  are a lot of TTS forums on here.

 

Paul firstly, no I never fitted the speaker into the loco just had it on a rolling road and placed next to it. Straight to Richard, as it was not fixed in place I'm thinking you could be right and something touched ? Like I say everything else works though and the speaker does grumble.

 

I called Hornby today, they said call Rails, if they don't replace they will except it back, Rails instantly mailed me a return slip straight away. I will be a bit more careful with the replacement and let you know how it goes. 

 

I did have a spare speaker but not sure on the ohms, as I read TTS needs to be a least 8.

 

Richard - I have a class 37 that's playing up, was thinking you could have a look and maybe add a more meaty speaker ? Am I right in thinking that's what you do ?

 

Many thanks again guy, really appreciate the help...

 

 

4 sound fitted, still about 7 to do....

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Handling a live decoder is not a good idea. If you were pressing the embedded sound chip to make ot work then that sounds like a duff decoder. Bridging the speaker connections on the decoder will make a different noise as your skin oils act as a current path and voltage divider across the speaker.

 

0 as a volume setting is OFF but how it got at value is probably one of life’s little mysteries. 

 

Even though the main sound is on or off at F1 all the other sounds F2 through to F24  should work and would prove the speaker connection/quality of sound. F25 is an aux power output that could be used for a cab light, etc.

 

I advise an additional (1K ohm) resistor in the blue wire feeding the lights to keep the current within TTS limits as the functions outputs are not self protecting like the motor circuit. It will also drop the brightness some and you may need an even bigger value if they are still too bright. I could use my Class 40 headlights as a torch.

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My replacement TTS decoder should arrive over the next few days,  Any advice, Did I do something wrong last time ?

 

I fitted the decoder but left the bodyshell off with the speaker hanging down by the side of the loco on a rolling road, could something have touched and damaged it ?

 

I am thinking do I need to fit/tape everything in place before I start it up ?

 

Many thanks

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Never handle a powered decoder. Only ever handle a decoder by the edges. Always insulate either the decoder or the loco and never let a decoder touch metal on the loco or elsewhere.

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  • 1 year later...
10 hours ago, Richard Croft said:

They go straight in but be careful how you position the wires, its easy to trap them when you put the body on

 

Richard

Thanks rich, do you recommend a better speaker to go with it or are the standard ones alright. 
 

 

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  • 2 weeks later...
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On 10/12/2020 at 20:56, scumcat said:

Please help

 

I too have a tts 66 issue. I have  bought the Hornby Tom Moore the loco was run in on dcc and performed well so I fitted it with a TTS chip it ran ok but it juddered on certain parts of my layout. I have since replaced the speaker with one from west wagon works, still a judder, i fitted lights using the illumination models kit and I have attached a stay alive to the tts decoder using strathpeffer junctions YouTube video as a guide. To try to cure the judder but it hasn’t helped. I have also removed the capacitor from the motor bogie. the stay alive works well I know because if you lift it off the track whilst moving the wheels still turn and the lights are illuminated. However today I noticed that the model judders on the parts of track that have droppers on them. This is really strange to me. The wheels are clean the track is clean, I am at a loss. I have been trying to adjust the CV,s but I don’t know what I’m doing and there are loads of posts on various forums with conflicting advice. As I said please help. My controller is the elite, and my short circuits are aided the old fashioned way with a car headlight bulb.

Its likely....the motor algorithm set on the TTS decoder is incorrect, what speed step does the judder occur at? Most juddering I have had is at slow speed, The Hornby 66 uses the same motor as my Limby class 31 and I have had to change the motor algorithm to get reasonable operation, its the same on the 8 pin Bachmann 37s and the super detail class 31s I have fitted and vitrains 37s and 47s.. in fact im yet to find a motor that TTS works perfectly with out of the box.......

 

Try those....

 

 CV3=35, CV4=20, CV150=1, CV153=215, CV154=0. Also, turn off DC running in CV29 

 

Also.....theres an awful lot of conjecture and discussion on a lot of American modelling forums about the use of car bulbs as short protectors....the gist is while they work.....they can allow a short to persist....and whilst at low currents that's fine....at higher currents....a car bulb puts out a tremendous amount of heat.....enough to start a fire!

 

http://www.rr-cirkits.com/Notebook/short.html

 

also....might be worth bearing in mind @RAF96 is a DCC beta tester for a high profile manufacturer. Might be worth reviewing what you have said as its a bit harsh!

 

 

 

 

Edited by pheaton
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Don’t fret about throwing rocks at me. I am used to it and take no offence. I can also be wrong as proven many times on here.

 

I suggested that if you scoped the track with a car bulb installed as a short protection it would likely show corruption of the DCC signal. I haven’t tried it myself, but I do know capacitors on their own corrupt the signal, but a snubber comprising a capacitor and a resistor in series damps any spikes without adversely affecting the signal.  

 

A car bulb exhibits odd characteristics as its resistance changes as it heats up and I would expect that change of resistance to affect things DCC, thus it may only kick in when there is a short circuit scenario and at that stage the signal has already been affected.

 

There are folk on here who know electronics inside out and are far better qualified than me to prove these things and I bow to their knowledge. In fact I would like to hear the theory behind it.

 

Edit: I found this interesting article which explains the theory and practice.

http://www.wiringfordcc.com/track.htm

I also found a diagram of a bulb with a polyfuse added which sort of defeats the object of the excercise.

Edited by RAF96
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The poly fuse is there @RAF96 because car bulbs can and sometimes do mask a short from the command station...and the concern is they can draw enough amps to melt wiring if the short were to go un-noticed for long periods, the poly fuse is there to blow should the bulb draw more than 0.9 amps if you are talking about the same diagram I have seen :) 0.9 amps was deemed to be safe enough to leave on for extended periods. 

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