7mm Installing a Loksound V4 XL Decoder in a Heljan Class 40

I have been busy recently installing decoders in Heljan 40s here is how I did it.
I am using a Loksound V4XL decoder.

The first thing you have to do is get the body off the chassis. Start by prising off the bogie and put them to one side. This time Heljan have been really helpful by hiding the screws that attach the body to the chassis, underneath what I think are some cross beams on the real thing these need t be prised out as well to reveal the screws underneath.








In the above image you can see the screws and the cross beam bits in the photo above you can just about make out the hole where the screws came from and the holes where the cross beam bits fit over them.

Once you have unscrewed the body it just slides off.

With the body and the bogies removed this is what it looks like.




This is the board from Heljan once its been removed. Again they are being really helpful by not telling you exactly what each wire does, you need to work it out for yourself.

So from the top of the board we have as follows. The front of the chassis is on the right in the photo above.

Slot 1

Red and black wires. The black wires are are for the front headlights and the rear tail lights. You can identify the front head lights as they split into 2 wires further down the chassis, the rear lights remain as one.
Front light wires go in slot FL on the decoder, the rear lights go in AUX 1 on the decoder.
The red wires are common and go in any of the U+ slots on the decoder (there are 3 slots marker U+).

Slot 2

There are 2 black wires, the rear head lights and the front tail lights. Again the rear head lights head to the back of the chassis and split into 2 wires. The rear head lights go into slot RL on the decoder and the front tail lights go to AUX 2

Slot 3

There are 2 red wires these are commons and go to any of the U+ slots on the decoder

Slot 4

This is a track supply and goes to TrkL left on the decoder.

Slot 5

This is the other track supply and goes to TrkR right on the decoder.

Slots 6-9

These are the motor feeds.

Slot 6 is motor left
Slot 7 motor right
Slot 8 motor right
slot 9 motor left

These go to Mot+ and Mot-
Make sure you get them the right way round for each motor so they both run in the same direction !

To get the motor the correct way round you need a red wire from one end with a black wire from the other end into each of slot M+ and M- on the decoder.

Once the decoder is wired up it looks like this.



You will notice that I have made a plasticard tray for the decoder to sit in. This is a simple 5 minute job the exact size is unimportant so long as the decoder fits in it.
The reason for this is that you must make absolutely sure that a short cannot occur on the decoder, if one does occur its probably going to be the end of your decoder. So check the wiring carefully at each terminal to make sure there isn't a little bit sticking out that can touch another one, because it can happen.

I would now test your loco to see if it runs properly and the lights work.
The headlights are designed to be automatic with the direction of travel and the tail lights are independently controlled on AUX 1 and AUX 2. These will be mapped to one of the function keys and will depend on who supplied your decoder. So for mine from South West Digital, AUX 1 is F13 and AUX 2 is F14, but for my decoder from Legoman, AUX 1 is F19 and AUX 2 is F20. The instructions with your decoder should tell you or you can read it on the Lok programmer.

If your loco doesn't run very well then now is the time to improve the settings.

The settings on the decoder from Legoman run much better than those from SWD.
These are the settings to change using the Lok programmer

On the motor setting screen

Reference voltage = 125 (12.5 volts)

K slow 48
I Slow 0
K 48
I 64

Regulation influence set to 255

Back emf sampling set to 8

Remember to make sure the back emf box is ticked.

I also tried these setting on Heljan Deltic and it runs better with too.



The next thing is the speaker

Cut the four posts off that supported the Heljan pcb and it will give you more space?
My speaker box sits in nicely pointing downwards with some thick plastikard either side locking it in. Then the chip can be mounted on the upturned speaker box, with a second speaker internally pointing upwards.

Personally I prefer 1 speaker much easier and you don't have to worry about the speakers interfering with one another.

I now use Cliff Williams speakers, they are excellent, a nice size big enough but not too big and as loud as you need.

In the 40's a 40mm speaker easily fits above the water tank underneath the decoder. The speaker needs an enclosure, Cliff sells one made fro brass but I prefer to make my own from plastic card it costs next to nothing and can be made in 10 minute.

here is a photo of it under construction



The sides are 25mm deep




two nice thick wires are soldered to the speaker, if you know anything about Hifi systems they always tell you to use nice thick wire that costs a small fortune for the speaker cable, so don't skip here.
The speaker enclosure needs to eb as air tight as you can make it so use fill in bits to seal the enclosure.





The speaker easily fits in the hole above the water tank. I then glue the tray to the speaker to fix it in place and use a bit of blu tack to hold the decoder in place.

If you are using one speaker then just wire one side to sp+ and one to s p- it doesn't matter which way round you do it. If you use 2 or more speakers then its essential that you get every speaker the same way round or they will be out of phase with one another and actually make the sound worse !



The decoder now sits on top of the speaker.

If you want to wire up the fan put the black wire to AUX 3 and the red wire to U+

Thats it the decoder is fully wired up.

You could add some more lights for the cab etc if you want to but there is no need if you ask me.

If have posted this on here for 2 reasons

1 so that I can remember what wire goes where and 2 to show how easy it is, it really is easy the first took about 3 hours as I made doubly sure what wire was what but he second 2 took about an hour each including making the speaker enclosure.

As for the motor settings you can play with those for hours but the ones above seem to work pretty weel for any Heljan loco. I shall be trying them this weekend on a few others and I will report back later with the results.

Be warned these only work on Heljan locos they don't work on coreless motors.

Richard, many thanks for posting your CV settings. I've been struggling for a while getting smooth running with a class 47 and these have helped.

One small query - which CV is the 'back emf sampling' value? I've searched through the v4 manual and I can't find a reference to this. I use Decoder Pro and that doesn't seem to have a suitable parameter either.

Julian

I have no idea, I can't find it in the manual either. I included it as its a setting on the Motor Settings page of the Lok Programmer, so included it for completeness. I have never changed it and every decoder I use has it set to 8.

Richard

No problem - I'm sure it's just a default value.

Thanks for looking

Richard
Just located this thread.
Did you try or manage to separate the white marker lights or just left them to show all at once?
thanks
Nigel

Nigel

I left them as they were originally wired by Heljan which I assume was all on. Its a while ago now and to be honest I don't remember.

Richard

richard carr said:

Nigel

I left them as they were originally wired by Heljan which I assume was all on. Its a while ago now and to be honest I don't remember.

Richard

Click to expand...

Richard

thanks for your reply, i thought i would try to separate them in order to give different train formation codes.,


Nigel

I'd just like to thank Richard and the others for the original and follow replies on this thread - I'm not sure I'd have converted my Class 40 without it. Useful of Heljan to use red and black wires through out, some of which broke just by looking at them...

I used a LokSound v4 XL, Cliff Williams speaker in the tanks, and an ESU roundy speaker pointing up, and it's loud... I removed the PCB for the fan controller, and knocked up another that could be mounted on the chassis as the original was fouling the decoder. The roof fan in my example is really quite loud when it's on, which is a bit of a shame - after I went to that bother...

I need to fit a crew, have a go at cab lighting and fix the broken MU cable at one end

Again many thanks.

(A different) Richard

Hi Richard , you can adjust the volume on the speakers with I think CV63 on the v4XL , do it on your programming track so you can see what its set at and then adjust to suit your ears .
Thanks also for those motor settings , I will have a play with my Heljans .
Cheers Paul