Decoder reliability

[Poppy choo choo]

I tell you guys I have started with Hornby sound and 4 output decoders and determined to continue using them unless I rid the lot and just do dc

BUT REALLY I'm getting sick of the reliability of the Hornby sounder decoders BUT that doesnt means that other decoders are any better.

Decoders work from new and then stop change the address from say 03 to 20 and no work go back to 03 address and then no work disconnect all power wait say 10 minutes and then address 03 works but you can't change the address go to change the address and nothing works extremely disappointed.

Im really disillusioned with the whole lot track maintenance for a long long time now Im restarting to play trains the maintenance should be sorted out with wheel cleaners etc

Do others have the same problems and really I should be able to sort out the problems being a electronic tech and engineer but to me as it stands totally Im very disappointed.

[Jupiter 1707822591]

Problems ? No !

Sounds like your layout has issues .

Try a snubber on your lines

Picture will be along shortly

[Chrissaf]

Many people have no issues at all and those who do usually have some fundamental issue with their set up.

As you say you are a techy person there are two techy things that can generate decoder issues which are described below, so that you can check them out to see if they are applicable to you.

Issue 1 - this issue particularly affects Hornby TTS decoders.

Check all your Hornby track power connectors to ensure that they are not DC Analogue versions. This includes R602, R8206 & R8201 products. These products include Analogue suppression capacitors in them that distort DCC signals and generate operational and control issues for DCC decoders. Also check the track connector on your "programming track". To access the capacitor, unclip the plastic cover located between the track on R8206 and prise apart the clamshell cover of R602 & R8201 products. Snip out and remove any capacitor you find inside. If you know for a fact that you are using R8241 & R8242 track power connectors then these are supposed to have the capacitors removed at the factory, but worth checking all the same as some R8206s were shipped as R8241s in error in the early days.

Issue 2

Transient short circuits. These are known to affect the configuration of decoders, this usually shows as a loss of address, typically but not always reverting the address back to the factory 03. These transient short circuit induced decoder corruptions can sometimes only be recovered by performing a CV8 = 8 factory reset and in severe situations damage the decoder beyond recovery. Even if this issue is not affecting you, the cure documented below is worth performing as an Insurance Policy.

Cure. Fit a "snubber filter" across your track. A "snubber" is a very simple two component circuit. A 0.1uF Ceramic capacitor rated at 100 volts or better, in series with a 100 Ohm resistor rated at 2 watts [1 watt can be used but this will feel very hot to the touch, a 2 watt resistor will feel cooler]. This filter reduces the size of the very high voltage spikes that transient short circuits generate on DCC power. It is these voltage spikes that damage the decoders, so keeping the size of them low using the filter, protects all the decoders connected to the DCC power. These voltage spikes are termed "ringing" and voltages up to 2 or 3 times the base DCC voltage can be generated.

If you want more technical information on "snubbers", navigate to the "Useful Links" sticky thread at the top of the "General Discussion" forum. Look for and follow the link to "Mark Gurries snubber theory". Mark is a founder member of the NMRA who devise the DCC specifications.

Note that the capacitor in the "snubber" is not the same as the unwanted effect of the Analogue suppression capacitor [issue 1], this is because the inclusion of the resistor converts it to a frequency tuned circuit that affects only the very high ringing frequencies leaving the base DCC frequencies largely untouched.

PS - I use PECO Electrofrog track with a full DCC BUS power distribution system [no Hornby track power products]. I was affected by "transient short circuit" decoder corruption on my Hornby R8247 Accessory Decoders. Now that I have fitted a snubber across my track BUS at the location where my R8247s connect to it, I have never had a single decoder issue since, including loco decoders.

This is an extremely long reply. Please do not try to reply using the "blue button with white arrow" as it is not a "Reply to this post" button. It is preferred if replies are made using the "Reply Text Box" at the bottom of the page and then clicking the green "Post Reply" button.

[Will Hay]

I find standard Hornby decoders first rate, but I do have problems with the tts decoders.

I've had extensive discussions with Hornby directly on this but unfortunately haven't been able to remedy it.

Mine sometimes decide to start up on their own, move rather than emit sound.

It's something I've learnt to live with, it's not often but for the price, with a change in speaker, they're excellent value for money.

[SteveM6]

Will, your runaway issue should be cured by disabling DC on CV29 and/or fitting ‘snubbers’ to your bus wires (if you use a bus).

Personally, the only decoders I have had fail we’re both Next 18 (clearly not fitted to Hornby locos) And as a result I have absolutely no faith in any loco that has those in their design.

[Chrissaf]

Just to add to Steve's reply, that you can still fit a 'snubber' across the DCC track even if there is no separate BUS wiring.

A 'snubber' can resolve all sorts of odd things that happen on DCC, as can the removal of any suppression capacitors that are used in Hornby Analogue track connectors R602, R8206 and R8201 which many have kept when upgrading from Analogue to Digital control. The Analogue suppression capacitors particularly seem to affect Hornby TTS decoders adversely.

[96RAF]

I have had TTS runaway both movement and sound. The problem is not unknown and has been reported on the forum before. The usual fixes suggested are turning off DC running in CV29 (now the TTS default) and also fit a bus terminator (snubber) to eliminate voltage spikes.

I had most of the problems on my 6x4 roundy-round test track which had a right lash up for a ‘power bus’, just loop wires track to track connected together and run to the controller.

Having sorted all that out on my latest layout I still have the odd TTS loco that will blow a horn or toot a whistle for its own amusement, but no further un-commanded movement. Many of my decoders are test articles but I could not say hand on heart that the faults I still get are due to being pre-production kit.

We shall see how the new sound decoders perform in service when they are released.

[Will Hay]

Will, your runaway issue should be cured by disabling DC on CV29 and/or fitting ‘snubbers’ to your bus wires.........

 

 

Hello and thanks.

Disabling CV29 [DC running] was my first action, before I engaged extensively with the superb tech folk at Hornby, and I don't have a bus.

Thanks again.

[96RAF]

You may wish to share the Hornby Tech Folk advice for the wider information of forum members seeing similar problems.

[ColinB]

I have had issues with TTS decoders blowing themselves up but not the issues like you are describing. I use Zimo decoders mostly but I do have a few locos fitted with Hornby decoders. I must admit the Hornby decoders are not as robust as the Zimo ones. You don't say what controller you are using for the DCC it may be that the controller is not programming them properly, that would cause issues.

[96RAF]

I have just watched a video (Malta N Gauge) where the guy solved his points firing problem by using a bus terminator at each end of his T power bus, which shows that these things do work.

[ColinB]

Surprising about DCC issues, I have a 16 foot by 8 foot layout with lots of different sections and I have no running issues with TTS decoders. The only issue I ever have is them dying, but I think that was more down to a cooling issue. I have an issue in that they are more susceptible to dirty track and stop and reset themselves. Interesting point though, on my brand new Rails class 812 with fitted sound, if the loco sees a bit of dirty track the LokSound sound decoder goes into DC runaway, it is also dependant on temperature as well. When I get round to it I will disable the DC setting and see if it fixes it.

[Bulleidboy]

I have had hardly any issues with decoders. I mainly use TCS decoders, and have a few Hornby TTS decoders. The only problems, if you call it that, is I bought five Hattons budget decoders, I tried all five in a Hornby M/N Class and the loco would only run at one speed and in one direction. I have not tried changing any CV's, but then you should not need to do that straight out of the box - they are now in the junk box. I have a Hornby R8125 decoder fitted into a Class 08 Diesel shunter in 2013, and it is still going strong and the slow running is incredible.

[Brew Man]

I have read that Hatton's decoders don't work well if at all with Hornby controllers.

[Bulleidboy]

I think I read that sometime after I bought themsleepy

[St1ngr4y]

@Brew Man

"I have read that Hatton's decoders don't work well if at all with Hornby controllers"

How can that be ? What are Hornby Controllers doing differently to other controllers to account for that ?

Ray

[96RAF]

I have read that Hatton's decoders don't work well if at all with Hornby controllers.

 

 

Maybe that comment should be simply - Hatton's decoders don't work well if at all. Full stop.

[ColinB]

Hattons decoders work perfectly well with my Elite. I bought a pack of 5 because they were cheap. I did find that they had a tendency to get hot and kill themselves, but at the time I was modifying a lot of old locos, so there could have been lots of reasons. I then found Zimo decoders which seemed to be much more reliable and weren't much more expense.

[Brew Man]

Maybe that comment should be simply - Hatton's decoders don't work well if at all. Full stop.

 

 

I've only ever experienced one Hatton's decoder which I bought with a King Class about a year ago, and guess what! it didn't work. I sent it back and changed it for a Hornby one. That didn't work either so I got a refund on the loco. So to be fair, the Hattons decoder might not have been faulty.

@St1ngr4y

I don't know what Hornby controllers are doing differently, it's just something I read and from more than one source.

[Bulleidboy]

I seem to recall that on the Hatton's site, it did actually say that these decoders may not work with some Hornby controllers.

[Chrissaf]

I suspect that these anti Hornby controller comments originate from Selects with old firmware versions i.e. version 1.0 to 1.3, there are still a lot of these earlier firmware Selects in circulation due to upgrades needing a "return to base" upgrade process.

[Brew Man]

I suspect that these anti Hornby controller comments originate from Selects with old firmware versions i.e. version 1.0 to 1.3, there are still a lot of these earlier firmware Selects in circulation due to upgrades needing a "return to base" upgrade process.

 

 

Could be. I can't think of another reason other than firmware issues with equipment that, (supposedly) conforms to NMRA standards.

 

 

[Fishmanoz]

My memory says there used to be a hardware solution too by putting a particular choke around the track cable?

But I agree with Chris from what we see here recently.

[Will Hay]

I have read that Hatton's decoders don't work well if at all with Hornby controllers.

Maybe that comment should be simply - Hatton's decoders don't work well if at all. Full stop.

 

 

As chrissaf has quote rightly pointed out in this very thread, many people have no issues at all and those who do usually have some fundamental issue with their set up.

[ColinB]

I never seem to have an issue with any make of the decoders working, some of them though do cause issues with my Elite when trying to program them. I will add Hattons ones program perfectly with no issues.