Okay, update on installation of Tsunami AT1000 decoders into my two 48 class locos.
First issue came when separating the body from the mechanism. Relatively easy to do, but a decision had to be made about the hand brake chain.
On the first loco I did, I actually popped the bogie side frame casting off the bogie (very easy to do....it was actually accidental on my part), so no problem on that one. However, when I came to do the second loco, the chain came away from the bogie and was left hanging on the body section. Later, when I finished the decoder install, I tried for 5 minutes or so to get the "D" shackle back on to the bogie side frame/air brake arm, before I finally gave up and snipped the chain off altogether!!! I'm too bloody old to be farting around with fine little details like that...beautiful though they may be!!
So, onto the decoder installs.
On the first loco, despite my loathing of seeing these types of locos (ie: hood types such as 45, 47, 48 and 49 classes) being driven long hood leading, I decided I would wire-up the lights at both ends.
The job started by removing all the plug-ins from the factory board and then removing the board itself (2 screws just fore of the speaker). There are 2 pairs of wires the come from the 2 slide switches located between the fuel tank and the two bogies. These wires/plugs aren't needed (they are for lighting purposes when a loco is being used as DC only). They were snipped off as close to the "floor" as possible and discarded.
I then cut a piece of thin styrene sheet approximately the same width and length as the decoder. I used Xuron rail snips to cut-off the 2 protruding lugs that the screws that held the original board went in to. The styrene sheet was then attached above the motor with Kapton tape at both ends and then the decoder was placed on top and secured with tape too.
The various wires were connected to the board, making sure I used a 1K ohm resistor on the white (common) wire from lighting boards.
The motor has a red wire and a black wire, with no indication as to which side of the motor is + or - .... It turns out that balck is positive and red is negative as far as the Tsunami decoder is concerned.
On this first loco, I placed the capacitor at the very back, under the light board, securing it horizontally with Kapton tape to the sides of the chassis under the speaker.
I tried to short-cut the lighting wiring by using the same "common" for both front and back lighting boards....utilising the front "common". I think that is the reason the rear lights don't work!!....But I can't be bothered fixing it as I don't intend to use those lights anyway, although it would probably be nice to have the red marker lights working I suppose.
On the second loco I totally removed the 4 tabs at the rear of the decoder, so that it would not protrude quite as far forward, even though on the first one it cannot be seen through the cab windows. I totally removed the rear lighting board from this second loco and this made the mounting of the capacitor slightly easier....it stands vertically where the light board used to be (I totally removed the plastic "bracket" that was there to hold the light board.
When my 830 class arrives I will be able to do the conversion quickly (I hope).
By the way, the choice of the Also 539T was probably not a good choice in hindsight, but it is certainly different to the 251 that the 44s and 45s have in them, so at least I can tell the difference.