loksound 4 Adaptive Regulation frequency

[gronk the shunter]

Hello,

 

Having just fitted a couple of Bachmann loco's with loksound decoders, both of them have noisier motors than before,( previously fitted with a lenz silver and a Bachmann decoder) with noticable humming/buzzing. According to the manual altering CV124 bit 4 to a value of '1' can stop the noise. However how do I alter bit 4? When I go into the programming menu on the powercab and select cv124, it does not mention any "bit" and I'm worried that simply changing a value in cv124 without accessing the "bit" bit will screw it up.

 

Please help!

 

Paul

[Lady_Ava_Hay]

All decoders operate on a bit value in each CV. If the default bit value in CV124 is known to you from the decoder manual then look for the value in bit 4 in the same manual. If it is '0' then adding '1' to the total CV value will change bit 4.

 

Quite how the decoder recognises that is completely beyond me but it works. Whether or not it will cure the noise is also beyond me but most decoders are adjustable for the type of motor in use.

 

The other thing you might try is to disable DC running. Again the manual will tell you which CV to change to do that.

[gronk the shunter]

Well I tried the CV124 thing to do avail, and disabled dc control. I could make it louder (not nice at all) but no quieter. I've messed about swapping the loksounds into other loco's and they make all the Bachmann ones noisier, to different degrees but still all worse. This doesn't seem to be the case with Heljans so much but there is a tiny increase in motor sound, prior to the loksound it had a lenz gold and ran silently. Is this a common problem, I can't remember reading about it, but a couple of years ago I had the same thing with a Bachmann 37 with a v3 decoder.

Is there something obvious that can be done like a cv change, and do zimo sound decoders do the same?

[pauliebanger]

All decoders operate on a bit value in each CV. If the default bit value in CV124 is known to you from the decoder manual then look for the value in bit 4 in the same manual. If it is '0' then adding '1' to the total CV value will change bit 4.

 

Quite how the decoder recognises that is completely beyond me but it works. Whether or not it will cure the noise is also beyond me but most decoders are adjustable for the type of motor in use.

 

The other thing you might try is to disable DC running. Again the manual will tell you which CV to change to do that.

 

David,

 

Your explanation of 'bit' and CV values is flawed.

 

I don't really know why these things are quoted in this fashion, it's not really necessary and it can be very confusing until you understand what it means.

 

It's a bit like being told you need, butter, eggs, flour, sugar, salt mixed and heated, instead of 'you need a cake'.

 

However, working from first principles can always get you to the correct outcome, if you understand the principles and the rules, so I suppose that's why this geeky terminlogy is employed.

 

 

In the context of '0' and '1' against a bit value shown in a manual or table, it simply means that the 'bit' should be 'Off' (0) or 'On' (1).

 

Each 'Bit' has a numerical value. For mathematical reasons, the bits read from right to left.

 

So:

 

Bit 7 is 128, bit 6 is 64, bit 5 is 32, bit 4 is 16, bit 3 is 8, bit 2 is 4, bit 1 is 2 and bit 0 is 1

 

The value of any particular CV is the total of all the bit values above, that are to be 'on' to achieve the desired result.

 

For example, CV 60, the manual says that for a particular thing to apply, no bits are to be set 'on' (ie all bits are 0), the sum total of all the active bit values is Zero, The correct setting for CV 60 would be a value of '0'

 

If it said CV 60 needs to have bit 3 =1, it means bit 3 should be set 'on', and therefore, bit 3 value added to the total.

 

Bit 3 value is (always) either '0' when off or '8' when 'on'.

 

So in this case CV 60 = 8 would be the correct setting.

 

Where multiple bits are to be active (CV29 is a prime example), do the same exercise to get the active bit values, and add them together. The resulting total is the CV value to be used.

 

Example, CV 60 needs bit 1, bit 3 and bit 6 to be 'on'. The 'on' values for the respective bits is 2, 8 and 64. The total is 74, so the value entered should be CV 60 = 74.

 

 

Now, to answer Paul's question about CV124, we don't know enough info to advise the actual CV value to enter, since we do not know the current value. But from the above, you can see that to make bit 4 active, Paul will need to add 16 to the current value, then use the new total as the value in CV124.

 

That is how the decoder recognises from the CV value, what is required.

 

Paul.

 

I have no idea if changing CV 124 will solve your problem (I only use Zimo decoders as they have the best motor control, usually perfect out of the box) but here's how to make the change anyway.

 

Put your Power Cab into Service Mode programming. Make sure this is the only loco on the layout, or programming track if you have one, and press the 'Prog/esc button 4 times.

 

The display will change to 'programming track', then press 'Enter' and wait for display to change. Select '2' to open CVs, then type in 124 and press Enter. Wait until the display tells you the value. ADD 16 to the value shown, (in your head) and type in the resultant total, press enter.

 

Press Prog/Esc to revert to normal running.

 

CV124 will now have bit 4 set to 1 (ie value 16), and any other bits will be set as before.

 

I hope this helps your understanding of bit values and the changes you make solve your noise problem.

 

Kind regards,

 

Paul

[newbryford]

IIRC, the Loksound v4's have a "self-tune" mode. It's been explained on here before, but can't locate it immediately.

 

Cheers,

Mick

[gronk the shunter]

Thanks Paul and Mick. I've tried the self tune feature which made no difference. the loco's all run well, just hum to themselves as they go about their business!

I think I'll try a zimo next to compare the difference. Plus I like the idea of having more control over the engine sounds compared with the loksound set up's.

[legomanbiffo]

The self-tune only works on Loksound v4 chips. If you tried it on a v3.5 it would make no difference.

 

Bif

[tarifa]

Hello,

 

Having just fitted a couple of Bachmann loco's with loksound decoders, both of them have noisier motors than before,( previously fitted with a lenz silver and a Bachmann decoder) with noticable humming/buzzing. According to the manual altering CV124 bit 4 to a value of '1' can stop the noise. However how do I alter bit 4? When I go into the programming menu on the powercab and select cv124, it does not mention any "bit" and I'm worried that simply changing a value in cv124 without accessing the "bit" bit will screw it up.

 

Please help!

 

Paul

 

Paul,

 

You may find that CV124 is not the CV to adjust the motor frequency as it is present as an additional configuration more applicable to the sound "function" of the decoder. I suggest that you look at CV 49 and ensure the setting is 19. This gives the motor enabled back-emf, 40kHz pulse frequency and speed step detection. The Lenz silver uses CV50 for the same motor activities although the maximum controlable frequency is 23Khz. You have not stated what loco's you are working with and if they are recent or older loco's to help with the diagnosis.

 

HTH

 

Mike

[gronk the shunter]

Hi Mike,

the worst loco affected is a Bachmann class 24, one of the early ones so probably around 8 years old or so .

 

Paul

BTW the chips are v4