DCC Bus Terminator/Filter/Snubber Wiring Diagram

Just a really quick post…

Someone asked me recently about DCC bus terminators (or, more accurately, ‘filters’ or ‘snubbers’), whether you should use them and, if so, how to wire them. So, I knocked up a quick diagram for them and I’ve uploaded it to the website in case it’s of use to others. It’s a very simple circuit!

There are different schools of thought on whether a terminator/filter/snubber is required. My own take is that for most small to medium layouts, they’re probably not necessary as a default. However, for bigger layouts or if you’re having reliability issues/unexpected performance problems, it’s probably worthwhile installing them.

If your DCC bus is a loop, then no filter is required (it’s also moot whether this is a good way to do it or not). If it’s a single run, then you only need a single filter at the end. If you’ve got for a T-shaped bus or you have more than one bus, then you’ll need a filter for the end of each run. Simples!

Note: Some people have reported conflicts and false positives with block/occupancy detection when a filter is installed – it’s something to be aware of. It perhaps also goes without saying, but remember that if you’re using block or occupancy detection technology, the filter should be installed on the end of the DCC bus and not on a leg from the detector module. 

It’s 2019: A new year, a new video!

Happy New Year! It’s 2019: a new year and a new video. After a break of a couple of months, we’re back to with a general layout and channel update.

Watch to hear about progress on the layout, modelling studio developments, background projects and the layout card board. I also talk about layout lighting and my new control panel.

Ringfield Adaptors

If you’d like to get a notification when the Lima ringfield adaptors are available to buy, please click here to join my mailing list.

Layout Cards

If you’re after a Strath Junction layout card or you’d like to send me one for inclusion on my board, click here.

Railway Modelling Community links

Visit Kirkton Road Junction: www.youtube.com/channel/UCkcK9BBtpYNWaGDmyZk753Q

Visit Strathpeffer Spa Railway: www.youtube.com/channel/UCVhtF1Jr-F28Rei_wbeLOqw

Join the Model Rail Network: www.youtube.com/channel/UCAu_DzB3v-SzDDdShZi8sTg

Visit MRYCG: www.youtube.com/channel/UCOw5PQM897D1TOpjcJIA9mg

We wish you a merry Christmas!

Wishing all of Strathpeffer Junction’s followers and subscribers a very Merry Christmas.

We’ve been a bit quiet of late due to a variety of factors, but once the Christmas madness has settled down, we’ll be back.

Have a great one, folks…

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


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.

Strathpeffer Junction YouTube Model Railway Channel Layout Cards

I was chatting to Paul at the Galgorm Hall model railway layout a few weeks back about railway modelling on YouTube, and model making and creativity online more generally.

One thing that we both loved about other maker channels, particularly amongst the woodworking community, is that folk share ‘shop cards’ with each other as a way to support other channels and give visual ‘shout outs’.

So, we decided we’d knock up some ‘layout cards’ for our own respective model railway YouTube channels and share them with each other to get the ball rolling.

And no sooner had we exchanged cards, when Simon from Liverton Central dropped us a line to get involved – and so it began!

I’ve also put together a small noticeboard, which I’ll hang on the wall in the loft and fill up with cards as and when they arrived. I’ve put together a short video explaining the thoughts behind this initiate – link below – and we’d love it if you’d like to get involved.

How to get a Strathpeffer Junction Layout Card

If you’d like a Strathpeffer Junction layout card, please click on the link below to send me your details. Please let me know if you’d prefer a magnet or sticker. Both variants now feature the Strathpeffer Junction station sign and YouTube design (see image above).

I originally had 50 cards to send out free of charge and with free UK/EU postage initially. I only have a handful of that batch left. Once the initial 50 have gone, I’ll happy send out the remaining cards in exchange for a stamped addressed envelope or contribution towards postage, or in exchange for your own card, which I’ll happily add to my wall of layout cards.

To get your Strathpeffer Junction card, please click here to send me your details. Make sure to include a UK/EU postal address. If you live further afield, I’m happy to send out a card if you cover the postage.

Got a layout card for your own channel?

I’d absolutely love to collect layout cards from other model railway YouTubers – be they in the UK or further afield – and add them to my board. If you’d like to send me one or you’d like to exchange one for one of my own cards, please drop me a line.

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.

Layout Update: August 2018 – Baseboards, Track Plan & Cataloguing Rolling Stock

It’s been just over two months since I posted a layout update. Despite the incredibly hot weather and other distractions of the Summer, I’ve still managed to make some reasonable progress up in the loft.

In this layout update video, I take a look at the track plan for the Strathpeffer Junction layout, as well as where I’ve got to with the baseboards, my initial thoughts for DCC busses and some sorting and cataloguing of rolling stock and locomotives.

I’ve had to jettison the idea of a two level layout with large fiddle yard below due to space constraints, so now it’ll be mainly one scenic level, albeit with an upper level TMD at one end with a small fiddle yard below that.

The station layout is loosely informed by Dingwall station during its heyday (click the map below for a larger image). There’s also a great thread on RMweb that looks at Dingwall’s layout in years gone by. You can read it by clicking here.

The plans show what I’ll be working towards, but are by no means set in stone. I’d love to know what you think about my plans and ideas, so please feel free to leave any thoughts, comments, suggestions and questions in YouTube’s comments section.

EDIT: In the video I put up text on the screen mentioning two booster units for my two power districts. I should have written one booster. The one district will be run run from the DCC controller itself (in my case, a Z21 black), and the one from a booster.

Installing a flashing tail (EOT) lamp on your model railway coach or wagon

When the Model Railway YouTube Community Group coach tour visited Strathpeffer Junction, we took the opportunity to drop the coach into Fodderty TMD for a quick once-over and flashing tail lamp installation.

This in-depth, two-part how-to series takes you through the installation process, step-by-step. Part A looks at designing and building a small rectifier and stay-alive/keep-alive circuit, from component selection to soldering.

Part B looks at adding a switch, installing the red tail lamp itself and, because the flasher unit used requires a specific voltage, the design and build of a small rectifier circuit.

The circuitry used in this video series is just as applicable for coach lighting circuits or most other situations where you need to get power from the tracks into a coach or wagon to power a light.

You can download the schematic for the circuitry here:


#StrathpefferJunction #MRYCG #NetworkYouTube

You can buy items similar to/the same as some of the consumables featured in this how-to via these Amazon affiliate links:

Prototyping circuit board: https://amzn.to/2OzU2Ez
Bridge rectifiers: https://amzn.to/2NYMQRq
Electrolytic capacitors (1000uf 25V): https://amzn.to/2n4Jm45
Electrolytic capacitors (mixed box): https://amzn.to/2v727bB
+5V 150mA voltage regulator: https://amzn.to/2n2KWDy

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.