Hornby Class 37 TTS Sound Mini-Series – Part 2: Adding a Stay Alive Capacitor to a Hornby TTS Decoder

Welcome to Part 2 of our in-depth mini-series looking at improvements and upgrades to Hornby TTS sound decoder-fitted locomotives. In Part 1, we looked at speaker upgrades, and in this second part we’re looking at making a stay alive capacitor unit and fitting it to the decoder.

Whilst focused on the Hornby TTS decoder, the principles and steps outlined in these videos are applicable for most other stay alive scenarios, including other types of decoder, coach lighting circuits, end of train (EOT) lamps and so on. It’s ideal viewing for anyone interested in this areas of railway modelling.

Making the Stay Alive/Keep Alive Capacitor Unit

As well as showing you how to make the stay alive unit itself and assemble all of the components, in this video there’s a brief explanation of the background to stay alive devices generally and the role that each of the components plays in the overall circuit.

+ Video Contents +

00:00 – Video introduction
01:08 – Intro to making a stay alive unit
02:18 – Overview of the components required
04:11 – Using resistors to manage in-rush
05:00 – The components in detail
06:26 – Circuit diagrams
08:40 – A quick word of capacitor sizes
10:58 – Putting it all together: soldering
15:40 – Adding hookup wires & heat shrink
17:22 – The finished article

Fitting the Stay Alive Unit to the TTS Decoder

In this final video, we look at adding the stay alive/keep alive unit that we made to Hornby’s TTS sound decoder. We look at where to solder the two wires and also how to adjust CVs on the decoder to ensure that the stay alive unit functions correctly.

While the specific steps relate to Hornby’s TTS decoder, if you wanted to add a stay alive unit to their entry level R8249 decoder, the steps would be fairly similar (although the negative leg would have to be soldered directly to the negative side of the rectifier). If you’re using a different brand of decoder, the principles will be very similar, but the solder points will be different.

+ Video Contents +

00:00 – Introduction
00:20 – A quick recap
01:20 – Examining the decoder
06:08 – Soldering it all together
14:52 – Testing the solder work
16:10 – Fitting it all into the chassis
18:05 – A word about CV settings
19:08 – Testing the stay alive unit
20:53 – Conclusions

Please note: the steps involved in fitting the unit do require a steady hand and competence with a soldering iron. Working with DCC decoders and tiny surface-mount components leaves little margin for error and it is very easy to permanently damage sensitive electronics if you are not extremely careful.

Circuit Diagrams

We’ve produced a couple of circuit diagrams to accompany this tutorial series. You can download copies for free using the links below:

Project Components

You can buy items used in these tutorials using the affiliate links below. Using these links helps to support this website and our associated YouTube channel and is very much appreciated.

Hornby TTS decoders (Amazon): https://amzn.to/2PbRM9x
Hornby TTS sound decoders (eBay): https://ebay.to/2S1P4Ca
Capacitors (15,000 uF 25v): https://ebay.to/2AljFnF
Resistors (100 ohm 1/4w): https://amzn.to/2yzLtDx
Decoder wire (red & black): https://ebay.to/2NR9fj1
Decoder wire (Multipack): https://ebay.to/2PGEYoK
Diodes (1N4001 50v 1A): https://ebay.to/2CXBifB
Diodes (1N4001 50v 1A): https://amzn.to/2ODFqYo
Heat Shrink (multipack): https://amzn.to/2PdO0N5
Heat Shrink (various sizes): https://ebay.to/2EvWI54
Kapton tape (10mm x 30m): https://amzn.to/2OBEpjB
Kapton tape (various sizes): https://ebay.to/2R2H2aU
Liquid Flux Topnik No Clean (Amazon): https://amzn.to/2Al6HpP
Liquid Flux Topnik No Clean (eBay): https://ebay.to/2CXy7EO
0.3mm Lead/Tin solder: https://amzn.to/2NT7pOy
0.3mm Lead/Tin solder: https://ebay.to/2S6Jpe0
Hakko Soldering Station: https://amzn.to/2CVLzca
Blue silicone electronics mat: https://amzn.to/2Pbv7ug
A2 green cutting mat: https://amzn.to/2P8aKy3
A1 green cutting matt: https://amzn.to/2P8aKy3

Disclaimer

This project does require a steady hand and competence with a soldering iron. Working with DCC decoders and tiny surface-mount components leaves little margin for error and it is very easy to permanently damage sensitive electronics if you are not very careful. If you choose to follow any of the steps or suggestions outlined in the video, you do so at your own risk and any damage or injury to yourself, your models, your equipment or others is your own responsibility.

Hornby Class 37 TTS Sound Mini-Series – Part 1: Mega Bass Speaker Upgrade

The is the first in a two-part series on upgrades and improvements that can be made to a Hornby Class 37 locomotive with TTS sound.

In the second video, we’ll look at adding stay-alive capabilities to help keep the running smooth and steady, but for now, we’re upgrading the stock speaker to something a little better…

The steps outlined in this video are applicable to all TTS sound decoders (and many others). The only differences being that in some locomotives – not least most steam locos – the space inside can be rather limited and you may not be able to fit such a large speaker into the body.

Remember that in all cases where a Hornby TTS decoder is used, you must also use a 8 Ohm speaker (or two 4 Ohm speakers in series, adding up to 8 Ohms). This is different to LokSound V4 decoders, which can use a 4 Ohm or 8 Ohm speaker.

Speaker impedance and decoder specifications for all common sound decoders are explained in more detail in our free guide, which you can download here:

Getting components for this project

You can buy some of the components and consumables used in this video, and give a wee bit of support to the channel, using the affiliate links below:

Megabass speakers: https://ebay.to/2N4VMnf

‘No Clean’ Solder Flux: https://amzn.to/2E9oOmK

Selection box of heatshrink: https://amzn.to/2zTbhv5

Black tack: https://amzn.to/2OCYhCg

 

Please note: If you choose to follow any of the steps or suggestions outlined in the video, you do so at your own risk and any damage or injury to yourself, your models, your equipment or others is your own responsibility.

Hornby Class 43 HST DCC & TTS Sound Speaker Upgrade or Replacement (R3602TTS)

Hornby have just released a brand new Class 43/HST set with TTS sound. It’s a fantastic model and the sound decoder is pretty decent too for the money, but, as is the case with most sound decoders, the factory-fitted speaker is a little tinny and doesn’t have much bass response to it.

In this in-depth video, I show you all you need to know about upgrading/replacing stock TTS & DCC sound speakers with a far superior Mega Bass speaker, including rewiring, body preparation (for anyone who doesn’t have a sound-fitted model) and installation. The improvement to sound and bass response from these new speakers is fantastic.

The HST set featured in the video is not a TTS-fitted model, however the steps involved in replacing the speaker are exactly the same for a TTS chip as they are a LokSound or Zimo decoder.

We look at both TTS and LokSound V4 decoders; the only difference being that a TTS (and Zimo) decoders must use an 8 ohm speaker, while the LokSound V4 can use anything between 4 and 16 ohms.

Speaker impedance and decoder specifications are explained in more detail in our free guide, which you can download here:

Looking to buy replacement speakers?

There are a variety of different retailers selling Mega Bass speakers (also called ‘High Bass’). Here are some options:

* Megabass speakers on AliExpress

Megabass speakers on eBay

* Highbass speakers from Coasal DCC

 

Please note: If you choose to follow any of the steps or suggestions outlined in the video, you do so at your own risk and any damage or injury to yourself, your models, your equipment or others is your own responsibility.

Making a Test Board & Rolling Road for Analogue & DCC Model Locos

I’ve been doing an increasing number of DCC decoder installations and model locomotive repair jobs – both for myself and others – and setting up my tester and rolling road each and every time I needed them was becoming a bit tiresome (not to mention the rat’s nest of cables).

After pulling what’s left of my hair out for the final time, I decided to put together a small loco and decoder test board, incorporating my LokProgrammer and SPROG, as well as accommodating off-board control integration (DCC and DC/Analogue).

The board also features a rolling road, using DCC Concepts rolling road modules, and my own take on a means to permanently integrate them into a test set up and improve usability, using acrylic sheet, spacers and screws.

You can download a PDF version of the wiring diagram for the test board featured in the video via the link below:

This is only one way of approaching a decoder test board setup and there other examples out there. I do recommend that you consider something like this if you’re intending to do a lot of decoder installation and maintenance – it saves a lot of time and hassle!

CORRECTION: in the video, I mention the acrylic/perspex sheet as being 6mm when it is actually 4mm. A thickness of 6mm is likely to be too thick and may interfere with the wheel flanges.

Project Components

You can buy some components for this how-to project via the links below. Buying via Amazon affiliate links means I get a (very) small donation and helps to support the website and channel:

– DCC Concepts rolling road: https://amzn.to/2C1IB6t
– Red and black wire pack: https://amzn.to/2C1Infx
– Green 2-pin terminal plugs/sockets: https://amzn.to/2PiVfiW
– Peco straight track: https://amzn.to/2LGgPM7
– A4 clear acrylic sheet (4mm thick): https://amzn.to/2Cae1Yk
– M5x8mm black nylon spacer: https://amzn.to/2Pq7tX4
– A4 plywood 12mm: https://ebay.us/LGRLYW
– A4 plywood 3mm: https://amzn.to/2C03bE2
– ESU decoder tester: https://ebay.us/aBLzSi
– SPROG dcc module: http://www.sprog-dcc.co.uk
– Green power panel-mount socket/plug: https://ebay.us/nBLfXz
– DC power-style socket: https://ebay.us/nBLfXz
– 3 position, 2-pole switch: https://ebay.us/WyKD3b

3D Printer STL Files

If you’ve got a 3D printer, you can download STL file for the 3D-designed parts for free and print yourself a copy:

Switch box/enclosure: https://skfb.ly/6B6Cy
SPROG3 cradle: https://skfb.ly/6B6DY

Please note: If you choose to follow any of the steps or suggestions outlined in the video, you do so at your own risk and any damage or injury to yourself, your models, your equipment or others is your own responsibility. Your own test board wiring requirements will vary depending on the components that you use and also the specifics of your design. The diagram provided above is only a guide and you must work out your own wiring needs yourself to avoid costly damage to programmers, testers and decoders.

Tutorial: TCS 21 Pin DCC Breakout Adaptor

In our last blog post, looked at the TCS-brand 21-pin breakout board, which can be used to permanent convert an 8-pin DCC decoder for use in a 21-pin chassis.

21 Pin DCC Breakout Adaptor Pinout Wiring Diagram

We’ve now put together a short YouTube video on how to carry out the modification, which you can watch below. We’ve also produced a wiring diagram to accompany the tutorial, which is available by clicking here.