Model Railway Forum

I’m steadily working through my collection fitting stay alive capacitors - either by incorporating the PowerBank with Hornby TXS decoders or by adding a homemade stay alive to TTS decoders.
That’s going well until I find something slightly out of the ordinary that my very basic knowledge cannot cope with - and I have such a situation this morning.

I’ve opened up a Bachmann 5MT that I had fitted with an 8 pin TTS decoder via an 8/21 pin adapter - but I see that the 21 pin socket already has a small electrolytic (I think) capacitor fitted. It seems to make no difference to the running qualities.
To be honest, the existing capacitor and the adapter make space very tight in this one so it probably won’t be a candidate for a ‘homebrew’ but if I remove the adapter and fit a 21 pin TXS there will be plenty of room for the PowerBank and speaker.

But that presents me with a question - when fitting the PowerBank (which plugs into the TXS decoder), do I remove the pre-fitted capacitor or leave it in place?

Could it be, and this is only a guess, that the existing capacitor is there as an RF supressor. If so then removing it will not effect the operation of the loco at all. How much of a problem RF interference is in these modern times I really dont know - Im going back to the days of 450 line TV and AM radios

I think the way forward (when I have the TXS decoder) is to remove the pre-fitted capacitor and check operation - I can always add it back in if necessary. My tally of decoders to be purchased is growing ever larger.

Meanwhile, I seem to have struck a rich vein of ‘difficult’ locos - a Hornby J36 has been disembowelled. I’m not sure I could even get a TXS powerBank and the ballast weight in at the same time. The ballast weight will need to go and be replaced by Liquid Gravity in the tender chassis so the caps can take up the space previously used by the weight.

I love reading this post. Really glad it is something I don’t have to do. Admire what you are doing Steve.

To quote professor Stanley Unwin "deep joy".

I have to say that, returning to railway modelling for the first tine since I did it with my dad in the 1960s, DCC scared me. Was never going to be my thing. However as im starting a fresh in N gauge i have been convinced its the way forward if youre starting from scratch. Ive been very involved in R/C planes and also raced cars and boats and having read up on it all its seems very similar to R/C except the commands are sent via the rails rather than radio signals. I appears that commands are sent via a variation in the mark space ratio of a square wave and all recivers are listening but only the addressed one responds. Apologies if thats drivel but it kinda makes sense to me . The required wiring is dead simple and reversing !oops seemless so whats not to like. Maybe not everyones cupof tea but im sold on it

“The wiring is so simple”.
They lied.
Actually it’s up to you how complex it can become, but a simple two wire solution it ain’t.

Ok maybe I was a bit over enthused yesterday gussing what i meant was its kind of comprehensible to my small brain

Nickk wrote: ↑Fri Jul 21, 2023 11:47 am Ok maybe I was a bit over enthused yesterday gussing what i meant was its kind of comprehensible to my small brain

I find it easier to accept DCC and Bluetooth as forms of witchcraft.

Completed the J36 conversion this morning - so little space to work with, even after the tender ballast has been removed.

2023-07-21_10-17-34 by Steve Mumford, on Flickr

After the challenge of the J36 I thought I’d convert an A3 with nice big tender - poor deluded fool that I am!
The DCC socket and a mounting post through the rear of the weight loses the rear third of the space and the sloping floor of the coal space loses the front third.
I managed to fit the decoder under the weight and completed some very compact soldering to get the capacitors into the central third of the tender. But I still had to lose the floor of the coal space. At some point I will make a new panel to fit over the resulting hole.

12EA9257-9E30-4904-8EB1-1F5E3B89376D by Steve Mumford, on Flickr