Does my LGB 21852 Mallet have a decoder?

S

samogrr

Registered
3 Sep 2020
9
65
Los Angeles
Am getting back into this hobby after many years away and am stumped right now. I just acquired an LGB 70685 Orient Express set and am trying to figure out how I can run the Mallet with some new to me LGB items (55005p Central Station, 50111 transformer, 55015p remote, 55016 remote).

When I set a remote to L 0, I can control the direction and speed of the loco. If I set the remote to another address like L 1, it doesn’t respond. Doesn’t this indicate that this 21852 Mallet has a decoder of some sort?

In doing some research, I believe that this set predates MTS? The sticker on the box mentions “Sound” and DC 0-24V but nothing about MTS. And the “OK” sticker on the bottom indicates that the Mallet was built in June of 1997. I’m guessing that a previous owner added a decoder and will look inside once I figure out how to open it up.
 
Zerogee

Zerogee

Clencher's Bogleman
25 Oct 2009
17,071
North Essex
Setting an MTS system to address "0" is the "pseudo-analogue" setting, so if your loco runs on this then it is probably not DCC-chipped. As the Mallet already has an LGB sound board, all you will need is a driving decoder with enough power capacity for a two-motor loco.

Jon.
 
ntpntpntp

ntpntpntp

Registered
24 Oct 2009
7,333
57
UK
Does the motor "sing" while the loco is stationary on the MTS powered layout? I don't know the old MTS gear but it could be it's running the loco without a decoder by bending the digital signal - some systems use address 0 for this functionality. DCC/MTS decoder addresses would be from 1 upward. Personally I wouldn't recommend doing this long term if the loco has no decoder, in the smaller scales it can destroy the motor.

The correct way to find out if a loco has a decoder (if you cannot physically remove the body to check) is to use a digital programming track and attempt to read the decoder. That only applies short pulses of power, and the system should tell you if it can or cannot find a decoder.
 
Zerogee

Zerogee

Clencher's Bogleman
25 Oct 2009
17,071
North Essex
It's not too difficult to get the body off one of these - the only tricky bit is that once you've removed the obvious visible screws underneath (from memory, I think it's probably two under the cab and two under the side tanks) there is an extra screw under the smokebox which is partly hidden by the front power bogie - to get at it, you'll need to gently twist/lift the front power unit as far as it will go to one side or the other, then you should just about be able to get a screwdriver in there!

Jon.
 
ebay mike

ebay mike

Retired, but still hoarding. (GOF)
6 Dec 2011
3,292
Norfolk - edge of nowhere.
I have one of those sets, but when I bought it I was supplied with documentation confirming it had been factory retro-fiited with a decoder. From what I've seen in historical reviews of the set it was supplied as analog with provision to upgrade to DCC. I am not aware that any changes were made to the sound unit so assume, like the 65xxx series, they can handle both systems without modification.
 
Tanker man

Tanker man

G scale and 5 inch ride on
10 Jun 2015
404
Oxford
I bought one of these sets , probably 20 years , new at the time, I did install 2 LGB decoders, they just plug in. The body comes off fairly easily, it's getting it back on is the problem as the 'walls' of the side tanks are free to fall off, as you try to put the body back on, can be a bit of a fiddle but not impossible, if you have 3 hands!
Dave
 
Zerogee

Zerogee

Clencher's Bogleman
25 Oct 2009
17,071
North Essex
Just remembered a quick addendum to my earlier post about getting the body off.... there are two air tank mouldings under the footplate that restrict the amount that the front power bogie can swing sideways - if you unclip and remove just one of them, you'll be able to turn the power unit much further on its pivot, which will make it much easier to access that sneaky hidden screw!

Once you have the body off, if you can post a picture here of what you find then folks can help with more relevant advice.
My own Mallet, which is around the same vintage as yours (or maybe just a couple of years newer) looks like this inside, before and after I'd installed a Massoth XL driving decoder linked to the original big sound board:

Mallet pic1-main board.jpg

New XL decoder.jpg

Jon.
 
P

phils2um

Phil S
11 Sep 2015
650
Ann Arbor, Michigan
Don't forget to throw all the little red switches next to the where the motor and track power leads (yellow, white, brown, and green) connect to the main board after you install the decoder. If you don't you might see the "magic smoke"! These disconnect the motor return from the rail. Check the leads with a VOM if you're not sure which direction the switches should be. There should not be continuity between either of the motor leads and track leads.
 
Last edited:
S

samogrr

Registered
3 Sep 2020
9
65
Los Angeles
Wow, thanks to everyone for your responses!

I’ll see if I can get inside to see what’s there in the next day or two.

Cheers,
John
 
dunnyrail

dunnyrail

DOGS, Garden Railways, Steam Trains, Jive Dancing,
25 Oct 2009
17,867
72
St.Neots Cambridgeshire UK
Am getting back into this hobby after many years away and am stumped right now. I just acquired an LGB 70685 Orient Express set and am trying to figure out how I can run the Mallet with some new to me LGB items (55005p Central Station, 50111 transformer, 55015p remote, 55016 remote).

When I set a remote to L 0, I can control the direction and speed of the loco. If I set the remote to another address like L 1, it doesn’t respond. Doesn’t this indicate that this 21852 Mallet has a decoder of some sort?

In doing some research, I believe that this set predates MTS? The sticker on the box mentions “Sound” and DC 0-24V but nothing about MTS. And the “OK” sticker on the bottom indicates that the Mallet was built in June of 1997. I’m guessing that a previous owner added a decoder and will look inside once I figure out how to open it up.
I had one of the Mallett sets with the 2 Pullmans Brown. Similar and probably about the same period as your Blue set. I fitted my Mallet with 2 Massoth XL decoders because there are 2 sets of contacts for 2 chips. Nit sure if just one would have worked but the 2 were fine. They were removed when I sold it as the buyer did not want DCC.
 
Zerogee

Zerogee

Clencher's Bogleman
25 Oct 2009
17,071
North Essex
Don't forget to throw all the little red switches next to the where the motor and track power leads (yellow, white, brown, and green) connect to the main board after you install the decoder. If you don't you might see the "magic smoke"! These disconnect the motor return from the rail. Check the leads with a VOM if you're not sure which direction the switches should be. There should not be continuity between either of the motor leads and track leads.

Good point, Phil - John, if your Mallet looks the same as mine inside, then it's the little block of red DIP switches on the front corner of the sound board. In mine, they were already set for DCC because the loco already had a very early decoder setup installed when I got it (a horrible lash-up of an old 55020 decoder and a 55030 "booster" to run the second motor) which was faulty - so I removed it all and replaced it with the single Massoth XL. If yours has never had decoder(s) installed, then the switches should be set the opposite way to those in my photos and you'll need the remember to throw them as per Phil's advice.

Jon.
 
S

samogrr

Registered
3 Sep 2020
9
65
Los Angeles
Jon, Phil, yes and thanks. Can’t wait to get inside. And about removing one of those those air tank moldings, Jon, thanks for that suggestion. I did find a spare parts listing for a 2085D and see that there are “hooks” on both tabs on the ends that prevent it from being pulled away. I’m guessing that after I remove the 6 Phillips screws that are not “hidden”, I’ll be able to slide something flat in there to nudge the tab(s) inward to unlock and remove the tank.

I have a couple of long screwdrivers on order from Amazon to be able to remove a couple of screws that are visible but that require “long reach”.

Cheers,
John
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
26,587
Tamworth, Staffs.
John,
If you have put your loco on your DCC-powered track, and it 'sings' ( a high-pitched 'buzz') then it does not have a decoder fitted..
Proof would be to select address '0' and se if it will then run. - Thisis the way you can run an analogue loco on a DCC track.

Don't do it for long, or leave the loco on the track for any great length of time, as it can heat the motor..

PhilP.
 
Zerogee

Zerogee

Clencher's Bogleman
25 Oct 2009
17,071
North Essex
John,
If you have put your loco on your DCC-powered track, and it 'sings' ( a high-pitched 'buzz') then it does not have a decoder fitted..
Proof would be to select address '0' and se if it will then run. - Thisis the way you can run an analogue loco on a DCC track.

Don't do it for long, or leave the loco on the track for any great length of time, as it can heat the motor..

PhilP.
The first post in the thread indicates that the loco indeed runs when address "0" is selected, Phil - which, as you've confirmed, I always understood as meaning there is NO decoder installed - otherwise I don't think it would respond at all to the "pseudo-analogue" signal that the MTS produces on address 0.

I think it's pretty safe to assume no decoder at the moment - the big question is whether, with a 1997 build date, the loco is JUST recent enough to have been made DCC-ready....?
That just pre-dates the introduction of MTS1, I think, but I believe that the factory had been starting to prepare for it for a couple of years before it hit the market.

The clincher will be whether, when opened up, the sound board has the pins for the decoders and the six-pin interface socket?

Jon.
 
Greg Elmassian

Greg Elmassian

Registered
8 Mar 2014
4,180
San Diego
www.elmassian.com
I have not done it, but wouldn't a decoder equipped loco still respond to the "address 0" trick? If "analog conversion" is enabled (DC mode in the vernacular) I believe it would work.

Has anyone tried this with a decoder-equipped loco?
 
railwayman198

railwayman198

Registered
24 Oct 2009
1,817
East London
I couldn't believe the 1997 manufacturing date, so I dug out the receipt for my set that I bought new from The Engine Shed (Gaugemaster). Sure enough, I bought it January 1998, for the considerable sum of £1299.95. Not only that, the box was so big it could not go through the loft hatch, so it was not a stealth purchase. It was not DCC ready but I had the good folk at GRS fit a decoder when I went digital a few years later. An excellent loco that continues to give sterling service.
 
Zerogee

Zerogee

Clencher's Bogleman
25 Oct 2009
17,071
North Essex
Am getting back into this hobby after many years away and am stumped right now. I just acquired an LGB 70685 Orient Express set and am trying to figure out how I can run the Mallet with some new to me LGB items (55005p Central Station, 50111 transformer, 55015p remote, 55016 remote).

When I set a remote to L 0, I can control the direction and speed of the loco. If I set the remote to another address like L 1, it doesn’t respond. Doesn’t this indicate that this 21852 Mallet has a decoder of some sort?

In doing some research, I believe that this set predates MTS? The sticker on the box mentions “Sound” and DC 0-24V but nothing about MTS. And the “OK” sticker on the bottom indicates that the Mallet was built in June of 1997. I’m guessing that a previous owner added a decoder and will look inside once I figure out how to open it up.

Just another quick question, if you haven't yet got round to opening the loco up - can you tell us (or better still, post a photo) what other stickers/labels are on the underside of the loco, aside from the gold "OK" sticker with the build date? Is there a round black or silver sticker with a number of dots on it, by any chance?

Jon.
 
ntpntpntp

ntpntpntp

Registered
24 Oct 2009
7,333
57
UK
I have not done it, but wouldn't a decoder equipped loco still respond to the "address 0" trick?
Not it doesn't respond, because the decoder is seeing a DCC signal and is listening out for commands on its address.

Think about it: if a decoder did respond to zero stretching then every DCC fitted loco on the track would respond together, but they don't.
 
ntpntpntp

ntpntpntp

Registered
24 Oct 2009
7,333
57
UK
John,
If you have put your loco on your DCC-powered track, and it 'sings' ( a high-pitched 'buzz') then it does not have a decoder fitted..
Proof would be to select address '0' and se if it will then run. - Thisis the way you can run an analogue loco on a DCC track.

Don't do it for long, or leave the loco on the track for any great length of time, as it can heat the motor..

PhilP.
Like wot I said in post #3 :D
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
26,587
Tamworth, Staffs.
Sorry to have repeated, Guys...
Had only scrolled-back a few posts.. Been to bed, and a lot has gone on here of late..

PhilP.