LGB #20761 and power buffer

[Tim Brien]

I have just fitted a LGB type '1' decoder and a LGB #65000 digital steam sound unit to a LGB #20761 'fat one' locomotive. All went well until the first frog. Loco and sound stopped. I either fit a trailing power pickup car (not my preferred choice), or fit a power buffer. I know many have chipped the Stainz type power drive block, so how do you get around the short power pickup wheelbase to ensure reliable pickup?

I have a spare LGB #65011 sound storage capacitor pack (looks similar to the Massoth Gold power buffer) that was intended for use with analogue ops on the sound board. Could it be refitted to the sound board and will it impact on the decoder operation?

The Massoth power buffers are fitted to the decoder '+' and decoder '-' terminals. If one is running reduced voltage (5 volts) for light operation, would this place the decoder '+' at 5 volts, or would one need the decoder set at full track voltage to ensure correct charging?

 

[dutchelm]

An alternative is to get rid of the rubber tyre. This is often the problem with poor pickup. However that loco will need more weight to pull anything.

 

[Neil Robinson]

I have a spare LGB #65011 sound storage capacitor pack (looks similar to the Massoth Gold power buffer) that was intended for use with analogue ops on the sound board. Could it be refitted to the sound board and will it impact on the decoder operation?

I would advise against trying this.
All I know for sure is that when using a digital interface to set an LGB sound unit up for analogue operation the sound storage capacitor pack must be unplugged from the sound unit. At best you just can't get it to respond, at worst I fear some damage may be caused, but I've managed to avoid that so far.

 

[Tim Brien]

Neil,
the reason for disconecting the capacitor pack is the initial inrush of power into the capacitors can cause the unit to give a false reading and possibly shutdown the programmer. Same scenario when using power buffers with a decoder. The unit will need to be disconnected when reading/programming.

I had already refitted the LGB #65011 storage unit as basically it is only a 'power buffer'. This gives me around 60 seconds of sound operation after power is removed. I will purchase a 4700uf power buffer from James Shourt to mount to the LGB type '1' decoder. This will give me a few seconds of motor operation to clear a frog.
The main thing is to keep the buffer leads away from digital track inputs to the decoder, as it is this that causes the magic smoke to escape.

Mike,
I looked at removing the wheel with the tyre, however, the pickup issue is present even when the non-traction rear tyre is involved at the frog. I tried running the loco through the frog from both directions, with the loco also picked up and repositioned 180 degrees to test if the traction tyre was the culprit. Loco still lost power no matter which direction.

 

[dutchelm]

Mike,
I looked at removing the wheel with the tyre, however, the pickup issue is present even when the non-traction rear tyre is involved at the frog. I tried running the loco through the frog from both directions, with the loco also picked up and repositioned 180 degrees to test if the traction tyre was the culprit. Loco still lost power no matter which direction.

In that case have a look at the point & check that the plastic frog is not too high and is lifting the complete loco up. Quite a few LGB points need a good helping of file to ensure the loco will run smoothly through.
I have a small shunting layout & had big problems with the jitters on points. All wheels with tyres have been replaced & points genetically modified. Now things run through at shunting speed without power buffers, even through the LGB 3 way point.

 

[whatlep]

I know many have chipped the Stainz type power drive block, so how do you get around the short power pickup wheelbase to ensure reliable pickup?

Three choices:
(a) - fit a power buffer. Expensive and may not solve the problem if the track is too dirty for the buffer to recharge or the buffer's supply time is too short.
(b) - operate in multiple with other locos or with a trail car
(c) - go for battery power

I use (b) and (c) for all my short locos, but the real answer is to buy a bigger (two-motor) loco!

 

[Tim Brien]

Well, fitting the sound storage pack (LGB #65011) was a positive move. It solved the shutdown issue going over frogs, ensuring constant sound. The capacitor gives about 60 seconds of sound with no power applied (more than enough for a single frog or two). I fitted an on/off switch inline to eliminate the sound decoder from the circuit when reading/programming the motor decoder.

Now I just need a power buffer to sort out the motor decoder problem. Fortunately, the little fat one has a little bit more space under the hood. A 4700uf will give me about two seconds duration and should be a comfortable fit. A larger 8300uf would be better, but I do not think that I have enough space left.