# Can a LGB loco AND a LGB sound card be run from 1 decoder?



## Jerry McColgan (Feb 8, 2008)

It is confusing to me that some LGB Moguls AND their sound systems can be run from a single decoder but other (older) LGB Moguls seem to require two decoders - one for the loco and another for the sound system. 

What brings this up is that I bought a LGB Forney with a DCC interface but without sound and I put a LGB 41352 sound unit with it to get sound with analog power. I could add a decoder to the Forney but would hate to spend the money on another decoder for the 41352 sound card just to get a chuff out of it. 

What I am wondering is if it would be possible to use a single decoder such as a LGB 55027 or Massoth XL to power the loco and lights and also to connect somehow to the decoder interface of the LGB 41352 sound card to get the chuff sound without buying another decoder for it. 

Does anyone know if this is possible and if so how I would wire it? 

Thanks, 

Jerry


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## Axel Tillmann (Jan 10, 2008)

Jerry a Zimo decoder can control the LGB sound and the loco. The LGB adapter makes it as easy as plug and play. 

But if you want best sound I would just go for the decoder/sound combo. Really superb.


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## Jerry McColgan (Feb 8, 2008)

Hi Axel, 

Thank you, 

Jerry 

Posted By Axel Tillmann on 05/07/2008 5:57 PM
Jerry a Zimo decoder can control the LGB sound and the loco. The LGB adapter makes it as easy as plug and play. 
But if you want best sound I would just go for the decoder/sound combo. Really superb.


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## Jerry McColgan (Feb 8, 2008)

To answer my own question - a LGB loco AND a LGB sound card CAN be run from 1 decoder!!! 


I like things to be simple and I hate having to read a bunch of 
technical manuals if I can possibly avoid it. 

For whatever reasons it just did not seem logical for me to have to 
read a bunch of technical stuff when all I wanted was to run some old 
LGB 41352 sound cards (chuff only) as sound units with my new LGB 
Forneys with DCC interfaces. 

I had made a special effort to buy some of the newest of the LGB 
41352 sound cards because they came with a decoder interface but it 
still annoyed me to think that I was going to have to spend almost 
$100 for a sound card just to get my $50 (net cost) analog sound card 
to work in the Forneys. After all, my whole purpose in buying the 
41352 sound cards was because I did not want to spend $150 or more on 
sound for a loco I don't run that often (and in which the LGB 6500X 
sound cards don't fit anyway. 

Lets face it. If I had to buy a $100 DCC decoder to run the loco plus 
another $100 or so to run that analog chuff only sound unit on top of 
what I had paid for the sound card I was getting close to doubling 
what the Forneys had cost me. I just did not think it was going to be 
worth what it was going to cost me - and I did not think that it 
should cost that much so I was not going to bother converting those 
Forneys to MTS/DCC. 

Somehow I just knew that I was right and I knew that there just had 
to be a way to do it. 

I finally took a 41352 sound card out of a loco and started playing 
with it using an ohm meter. As I compared the sockets on the 41352 
card with the sockets on a Massoth L decoder I realized that all LGB 
was doing with the decoder switches was to redirect the sound card's 
power input from track power to power coming from the decoder and the 
decoder was getting its power from the wires that were going to the 
motor. 

In other words the decoder was not decoding anything except perhaps 
that it might switch the sound on or off and perhaps it could control 
the voltage going to the sound card to adjust the chuff rate. 

This surprised me because I was expecting some sort of pulse from the 
decoder to control the cyclic rate of the chuffing but since there 
were no terminals for an input to control the chuff (as some of my 
sound cards that were designed for MTS/DCC operations have) it 
suddenly struck me that the motor operates on plain old analog track 
power. All the decoder does for the motor is to take the constant 
MTS/DCC track voltage and convert it into a variable DC voltage to 
control the speed of the motor. 

If the decoder running the loco is varying the DC power to the motor, 
then why the heck couldn't I take that same variable motor power and 
feed it to the analog sound card to do the same thing and vary the 
chuff rate according to the varying speed of the motor? 

The only way to know for sure was to do it. 

Since I had bought some LGB 55027 Decoder III (DCC interface) 
decoders I realized that they were rated at 3 amps which was far 
beyond what a LGB Forney motor would need and certainly to handle the 
additional load of a LGB analog sound card. 

I took the first Forney (a D&RGW) apart but then I discovered that 
the LGB analog sound card I had used was not a 41352 and did not have 
a decoder interface. 

I was going to strip a 41352 card out of another loco but then it 
dawned on me - what difference would it make if I was going to power 
it with the motor voltage? Heck, I just spliced two wires to the 
yellow and green decoder to motor wires and fed the spliced wires 
back to the track power inputs of the old LGB analog sound decoder 
and disconnected the track power going to it. 

As I connected MTS/DCC power - NOTHING HAPPENED. NO SOUND! I thought 
I had screwed something up and looked for the tell tale smoke or the 
burning electronics smell but everything was quiet. 

I added some power and the loco started moving - and the sound 
started. 

I realized I had been expecting the MTS all the time sound and I had 
not bothered to connect a 9 volt battery. I then attached the battery 
and then the sound started working even at low speed. 

I flipped back to analog track power and everything kept working just 
as it had before. 

The only difference (problem) is that under MTS/DCC the chuff is 
faster than I want it but I suspect I can fix that with either a 
resistor or lowering the loco start voltage. 

The result is that it may not be elegant. It may not be perfect. I 
may have to add a mini SPST switch to turn the sound on or off rather 
than push a button to do it and I might even have to look at a manual 
to see how to change the loco start up speed - but probably not - 
because I will possibly be able to do it by clicking on an icon in 
the LGB PC module software (since I am using a LGB decoder). 

What is important to me is not that I have accomplished as much as a 
plug in decoder would have done (I have not) but rather that I have 
lowered my cost to add MTS/DCC - AND MTS/DCC COMPATIBLE SOUND for the 
total cost of a single decoder which is exactly half of what I had 
been expecting to either pay or to have forced me to do without sound under 
MTS/DCC operations. 

What is even more important to me is that I have at least 20 other 
LGB locomotives including 9 or 10 2-4-0 Starter Set locos that are 
decoder ready but have either LGB 4135/41352/4367 or higher quality 
non-LGB analog sound systems such as Sierra Soundtraxx that I now realize I 
should be able to convert to MTS/DCC capability for the price of a 
single decoder. 

There is absolutely no way that I would ever have spent as much as it 
would have cost to buy 40 decoders for these locomotives but if I can 
do the same job (meeting my expectations if perhaps not others') with 
20 decoders I might eventually do that or more likely I might buy 10 
or so decoders - just for the passenger trains - to keep the lights 
on for when I or my granddaughters want to run them. 

Once I got this far my mind started roaming and I realized that I can 
probably convert the Phoenix sound system in my decoder equipped F7 
ABA to work with MTS/DCC by simply doing the same - feeding the power 
to the Phoenix sound unit from the motor leads (from the decoder) 
instead of the track leads. 

Another thought then came to me in that I had not wanted to remove 
and rewire the rear loco from my ABA or ABBA's to get them to run 
right using my LGB Loco Remotes (that cannot double head) but I don't 
have to. I now think that I will simply remove the wires from the 
motors where they plug into the decoder and by taking the connector 
off and putting it back on after flipping the wires 180 degrees, I'll 
bet everything will work fine without reprogramming anything. I might 
be wrong on this as I have not looked at it yet. 

I have always preferred the two wire simplicity of my analog track 
powered layout. It seems that what I really had needed to do was to 
ignore the decoders themselves but look instead at the two wires 
going to the motors because by doing that I think I have found analog 
track power solutions to my MTS/DCC questions. 

Two wires and a multi-meter. That is the sort of problem solving I am 
comfortable with. 

I am NOT making any sort of recommendation to anyone to do anything. 
On the other hand perhaps others who already have analog sound 
systems and don't want to have to buy extra decoders or new DCC sound 
systems might want to think about this. 

It should be mentioned that the above would not enable any MTS/DCC 
sound functions such as pushing a button for the bell or whistle. 
This is nothing more or less than a cheap substitute for someone like 
me who in some circumstances and with some locomotives might be 
willing to settle for less such as track magnets rather than buttons 
to activate bells and whistles. On the plus side none of the factory loco 
MTS/DCC features were lost or had to be reprogrammed since they now work 
through the decoder as LGB intended. 

In effect this IS NOT MTS/DCC at all. It is simply continuing to run 
the sound system under analog power (from the motor's power feed instead of 
from track voltage) variable voltage while the loco itself is running 
under MTS/DCC. The primary (only) motivation for me doing it is that 
it will give me MTS/DCC capability where I otherwise would not have 
had it. Would I recommend it? Nope. Will I do it myself? Yep. 

If I bought a new LGB Mogul/Mikado/F7 tomorrow and it had a DCC 
interface but no sound - I would probably buy a DCC interface ready 
decoder and a DCC sound system for it. 

If on the other hand I bought another LGB 2-4-0 it would probably get 
a single decoder and I would wire one of my spare LGB 4135/41352/4367 
sound units to that decoder's wires going to the motor. Others might 
prefer a better sound but for my 2-4-0's the LGB 4135/41352/4367's 
are good enough for me. 

Jerry


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## Jerry McColgan (Feb 8, 2008)

Sometimes I try things and they work. 
Sometimes I try things and they do not work. 
Sometimes I try things and they just seem to work. 

This was a time when they just seemed to work. 

I finally got my D&RGW Forney put back together (I'm still not quite happy in that I ended up putting the 55027 decoder in the cab because I could not find a place to hide it). One problem I discovered with 3 amp decoders is that their wires are a lot thicker which makes them harder to work with. 

Once together, I soon realized that with the sound board connected to the motor leads from the decoder, the analog sound works OK in analog mode but runs only at high chuffing speed when in MTS mode. 

I would guess that the motor is getting a pulsed DC voltage (rather than straight DC voltage) and that the sound card is reading the high end of the voltage. 

Still, since the LGB instructions say it is OK to run the Circus Sound card on MTS without a decoder I figure it is safe to run the sound card as well (it just will be without a variable speed). 

While I have not met all of my objectives I have met enough of them to consider the results to be better than I had and good enough for me. 

1. the loco now does run under MTS or analog track power - which means I can now have multiple operators running multiple trains on the same track at the same time. 

2. because the loco will run under MTS I can run it with the coaches still lit while the trains are parked at the stations. 

3. under analog track power (which I run almost all of the time) I have not lost any functions or capabilities (the sound functions normally). 

I will go ahead and add a decoder to the other Forney (PRR) that I run with the D&RGW because they are both passenger trains that I run at the same time on the same track. Adding the decoder to the D&RGW also made it a run lot slower than the non-decoder equipped PRR Forney. 

On the other hand I will forget about converting any of my other Forneys or any of the 2-4-0's to MTS because I was willing to buy a single decoder for at least some of them but its not worth it to me to buy two decoders for any of them. 

MTS/DCC wins two but loses a dozen or more (conversions). 

I have not totally given up but I want to correct my incorrect comments that the decoder to motor leads offer a source of analog DC voltage. 

I may try a few different capacitors (perhaps with a diode) to see if that might help. I seem to recall that some of my sound systems came with some sort of adapter to adjust for PWC. Perhaps they can work with MTS as well. 

Jerry


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## rwbrashear (Jan 5, 2008)

Jerry- 

I assume this wasn't a 'decoder interface' 41352 sound unit? (It was the older analog style unit?) 

Best regards, 
Bob


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## Jerry McColgan (Feb 8, 2008)

I have changed my mind about not using decoders with my LGB Forneys - and a bunch of other locomotives. 

Now that I have discovered both the Digitrax DH123D and MRC AD322 decoders and a buffer circuit to enable them to work with the LGB Sound Car analog sound systems my plans for cheap DCC sound are back on track. 

Jerry


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## Jerry McColgan (Feb 8, 2008)

After thinking everything over a time or two I decided that I really am a "Analog Guy" and I just finished removing the decoder from the D&RGW Forney. 

When I considered the expense, effort, chance of breaking something (particularly tough in these no-LGB importer days) and limited benefit (for me in accordance with what is important to me) I came to the conclusion that LGB locos that came with factory decoders and factory sound are nice to run on MTS but it just is not worth the effort and expense to me of converting my analog locos to MTS/DCC. I'd rather have $350 LGB Forneys with LGB analog sound (chuff only) that run on analog track power than to have $550 - $600 LGB Forneys with MTS and digital sound. 

Of course this is nothing more than an observation of what I think and has nothing to do with what anyone should do or what is important to them. 

I will put decoders in Thomas the Tank and a LGB Circus loco for the grandkids to play with and I'll also probably put a decoder into a LGB Track Cleaning Loco but the rest of my analog trains will most likely remain analog only. 

Naturally I put the decoder plug back incorrectly so I had to disassemble the loco yet again to put in in correctly. By the time I finished I had disassembled the Forney FOUR (or more) times - only to get back to where I had started. 

Somehow removing that decoder from the D&RGW Forney gave me a sense of relief. It was kind of like "coming home again" - where I was most comfortable - and belonged. 

Jerry


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## Jerry McColgan (Feb 8, 2008)

I had just about given up on my idea of running a LGB Forney (DCC interface) with a 41352 (or similar) LGB sound system from a single LGB 55027 decoder. The combination did not seem to work for me. The sound unit chuffing went to full speed immediately. 

I had become convinced that decoder output (even the motor output) was a pulsed voltage (PWM) that the various analog sound units could not handle. 

While reading the Spring 1996 LGB Telegram Vol. 7, No. 1 page 37 it seems that the author Heinz Koopmann was successful in doing what I could not (I have also since heard from others who have run analog sound units under MTS/DCC). 

Heinz did not bother with a full fledged decoder installation. He simply connected the decoder to the motor and track and then connected the loco electrical circuit to the motor output pins. 

On page 39 Heinz said the sound system will work like it did before because it will receive variable DC voltage through the motor pins. 

This is precisely what I had tried. He had used a LGB 55020 decoder and did not mention the sound system - but - if it it worked for him it should have worked for me. 

The result is that the loco operated exactly as before but with MTS selective loco control (EXACTLY WHAT I HAVE BEEN TRYING TO ACHIEVE). My other objective (less important) of keeping the coach lights on would be resolved as well by powering them from the MTS/Analog tracks rather than via the tender so the coaches would stay illuminated at all times under MTS. 

The concept of simply powering the locos as if they were still running analog (motor output only) seems to offer a way to continue with analog compatibility and the use of the factory sound unit batteries. 

My primary interest in MTS is so that my granddaughters and occasional visitors can be handed a MTS remote and take control of a single locomotive while others take control of different locos. Since I am not going to remove my track magnets the remote bell and whistle are less important to me. 

The locos used would primarily be LGB 2-4-0's and Forneys with 4135/41352/4367 sound units. 

I used a LGB 55027 Decoder 3 with a LGB 4367 analog sound card but it did not work for me. The sound unit went to full speed. This made me think that a different decoder might work. 

What also appeals to me about just using the motor output is that I could then retain my current smoke, lights etc. AND not have to worry about reprogramming anything other than perhaps the analog voltage motor output. 

As I understand it, using the motor outputs leaves the loco thinking and operating as if it was running under analog track power - but with multiple user loco selection - which is what I am looking for. 

The only decoders I have (to test with) are 55027's and XL's. 

For some reason when I first tried installing a 55027 in a DCC ready Forney with a 4367 sound card it seemed to work but after I reassembled the loco the sound unit went to full speed. I then removed the decoder and gave up - until I read the Telegram article. 

I only have the LGB 55045 MTS PC Decoder Programming Module and 55015 Universal Remotes to work with so this complicates my trying to find out what other brands of decoders can do. 

Then it dawned on me. If I wanted to test the motor output of a decoder to see if it could power an analog sound unit, why not simply put the decoder between the power supply and the tracks and test the loco and decoder and analog sound system all at the same time by running the assembled loco around a small layout? This way I could try any loco and sound system combination by just placing the loco on the decoder controlled track. 

I have LGB 55027 and Massoth XL decoders available and since they are both 3 amp decoders they should have enough power both for the locos and the power supplies but I did no expect them to work based on my earlier experience with a 55027. I decided to try it again anyway. 

SURPRISE!!! 

Both the 2-4-0 AND the Forney worked perfectly well under analog DC power while being fed through the motor outputs of the Massoth XL decoder. 

Then I switched track power to a MTS Central Station 2 powered by a 6 amp 50111 AC supply and... 

The old analog sound units kept on working just fine and with full chuff variance according to the Loco Remote throttle. This was with a LGB Santa Fe 2-4-0. 

Since I now had 5 amps MTS power I added three lighted coaches (powered from the track) and everything kept on working except that (naturally) the lights dimmed when I lowered the throttle. 

Now I was getting excited so I then tried the Santa Fe Forney and once again the loco, smoke, lights and sound system worked under MTS just as they did under analog power. 

I then turned on a siding with a LGB US type Stainz LG&B loco with a connected LGB motorized sound tender and with 3 LGB LG&B 2 axle lighted coaches (still being powered via the rear connector of the motorized tender which was still connected to the loco. 

Everything just kept on working just fine!!! I had full loco control with the Loco Remote but now I had selective loco operation (assuming a decoder was installed in each loco with a different loco ID. 

PLEASE REMEMBER - I am NOT advocating that anyone should copy what I am doing and I am NOT suggesting that anyone would want to do what I am doing. 

I still personally prefer analog track power 90% of the time. I am not trying to convince anyone to do anything - I am simply on a quest to discover a way that I can occasionally run my existing (running from super cheap to Sierra & Phoenix) analog sound systems from a single decoder under MTS while retaining a simple (instantaneous) change back to analog operations. 

ALL I am trying to accomplish here is to gain multiple train OPERATORS capability - NOT to achieve full MTS capabilities. 

My other desired effect of full time lighted coaches will be achieved as well because once the decoders are installed in the locos the coaches will get their full time MTS lighting from track contacts to the MTS powered tracks. 

The only strange thing that I noticed was that the loco headlight is still directionally controlled but while the reverse light does not come on in forward it only flickers in reverse (on at least two locos) so that may represent a potential problem. 

Actually I now am left with a new bunch of unanswered questions because based on my previous experience with the 55027 decoder I had absolutely no expectation of the analog sound units working with the XL decoder. 

I have 20+ (mostly inexpensive starter set) locos with LGB 4135/41352/4235/4367 series sound units that I am perfectly satisfied with (for the locos they are installed in) so this subject is VERY important to me. 

I found the following Phoenix and Soundtraxx Sierra bulletins on using their analog sound units under MTS/DCC: 

http://www.phoenixsound.com/pdf/DCC97.pdf 

http://www.soundtraxx.com/documents/techno...a/technote7.pdf 

My knowledge is still developing so I would not claim that anything I might say or may have said is accurate. It is only accurate to the extent of my personal experience to date. 

Next I repeated my above tests using a LGB 55027 decoder. 

At first (just as with my original Forney tests) the results seemed good but then I noticed that while the chuffing rate of the LGB sound boards does vary it started much faster with the 55027 than with the XL decoder. I also noticed that this seemed to happen with a variety of locos and the decoder seemed to get warm. 

The heat may have been from poor connections to the 55027 because it was difficult to get wires into the DCC interface. 

It is also possible that the 55027 I used may be slightly different from factory settings in that I bought it from an individual rather than from a dealer. 

It is possible that I could reduce the chuffing rate of the sound card with a resistor in it's input circuit. Unfortunately none of the LGB (boxcar) sound cards have a chuff regulator but a resistor would seem likely (to me) to be able to slow it down. 

I don't think I could effectively change the chuff rate with the decoder motor circuit because that would probably change the loco speed and could have other adverse results. 

My current thoughts are that I probably need to use a 3 amp decoder (55027, XL or similar) to have enough power to safely power the motor(s), lights, smoke and sound unit. 

With the 55027, as with the XL, the reverse light flickers when in reverse but the front & cab lights work as does the smoke unit. 

I am beginning to think that my original idea of putting 55027's into the DCC ready Forneys (standard plug in installation) with a tap from the motor circuit to the 41352 sound card may work if I find a properly sized (or variable) resistor to reduce the chuff rate. 

While I would hate to go back to installing, testing, reinstalling as I had done before, now that I realize I can do the decoder testing without even installing the decoder I should be able to determine if it is possible and practical for me to use the 55027's with the Forneys. 

If it works I will have achieved my goal of a relatively inexpensive single decoder installation in the Forneys including converting the LGB analog sound units to MTS compatibility. 

I'm not home free yet but I think I am making some real progress. 

The flickering reverse light on the locos does concern me. If anyone understands why this is happening and if it represents potential damage to anything I would appreciate hearing your thoughts on it. My suspicion is that it has to do with a polarized PWM voltage that is of insufficient frequency to keep the light illuminated. 

I can live with it as long as it is not going to cause any damage. 

I would prefer to use 55027's in the Forneys because the Forneys have a DCC interface for the 55027 decoders, should require a minimum of programming and they are compatible with the LGB PC module. 

If I am able to confirm that the LGB 55027 decoders can run the LGB analog sound cards from the motor circuit (perhaps with a resistor to lower the chuff rate) I will then install them in the DCC interface with a splice from the motor circuit to the sound cards. That would result in a single decoder and just two wires to power the LGB (chuff only) sound card. That should provide MTS control of all loco functions. 

By using the Massoth XL decoders in the LGB 2-4-0's with the same LGB analog sound units I should be able to achieve the same thing with a LGB adapter wire to convert the XL decoder to the LGB decoder ready socket of the 2-4-0's. 

In both cases (if this works) I will have achieved MTS/DCC/Analog capability with a single decoder cutting my cost of the conversions in half. 

I am posting this in case anyone else is interested in doing a similar conversion and also to find out if anyone has previously done this successfully. 

When I am done I realize that I will still have just an analog (chuff only) sound system - but what is important to me is that I have been happy with those analog sound systems, they are paid for, and my cost per loco to convert to multiple users on MTS will save me about $200 for every loco for which I don't buy a $300 DCC sound system - IF this works. 

The Massoth eMOTION XL seems to work but I have not installed it yet and I still have not reached a point of success with the LGB 55027. 

As always, this is for information only - I am not recommending that anyone should do anything. 

Jerry


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## Jerry McColgan (Feb 8, 2008)

I've changed my original plans to try to run both the loco and a LGB 4135/4235 series analog sound system from a single decoder. 

Now that I have discovered cheap decoders such as the Digitrax DH123D and (even better) the MRC AD322 decoder my plans are moving ahead. 

http://www.modelrec.com/search/product-view.asp?ID=1271 

They do not work by themselves (they require a buffer circuit to smooth out the DCC pulses) but that can be made for a couple of dollars or less. 

Jerry


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## Greg Elmassian (Jan 3, 2008)

The key to one of your questions is in the circuit. Most DCC (MTS) decoders output PWM power to the motor. You need to filter this for most "analog" sound cards. Notice the 220 microfarad capacitor frm the green and yellow output leads? That is the filter that will reduce the effect of the pulses, mostly smoothing them out to something close to analog DC. The 220 ohm 1 watt resistor is a load for the motor decoder, probably because it is expecting a reasonable load like a real motor. 

Regards, Greg


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## Jerry McColgan (Feb 8, 2008)

The following is the filter circuit I ended up with for both the Digitrax DH123D and MRC AD322 decoders. 

The MRC decoder seems a much better choice and at the price it is one heck of a bargain in my opinion. On the other hand the Digitrax decoder is MUCH smaller so there are times when I am still using the Digitrax decoder. 










Jerry


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## Jerry McColgan (Feb 8, 2008)

I've used this circuit with numerous LGB Sound Car analog sound systems such as the 4135s, 4235s and 4367s. 

While the sound has no chuff or whistle and is an older analog technology it gives me a very inexpensive sound system considering that I already owned the sound cars. 

Jerry


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## Jerry McColgan (Feb 8, 2008)

I should add that I am not recommending these decoders or the circuit to anyone. They are working very well and to my complete satisfaction but my expectations with the sound systems are very basic - all I am seeking is the ability to enable the chuff only sound cars to work under MTS/DCC as well as under analog track power. 

They do not (in my opinion) offer an equal quality or features with higher priced premium decoders but my objective was to avoid paying premium prices for a chuff only analog sound system. In that I have been successful. 

If anyone else wants to try it they are welcome to do so and I am willing to offer what limited assistance I can. 

Jerry


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## Greg Elmassian (Jan 3, 2008)

You can get what you want from Digikey or Mouser. 

The cap is called a non-polarized electrolytic (NPO). You can also "make" one from 2 normal electrolytics in series, but you have to use normal ones of double the capacity, thus 440 mikes each. Look for the NPO one first. 

You should be able to find what you want from the places above. 

Regards, Greg


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## Jerry McColgan (Feb 8, 2008)

Hi Greg, 

I found the resistors and capacitors at Digikey and now that I have been using them I have to say that I have been very pleased with them. 

Each filter circuit ended up costing me around $1.25 and is very easy to assemble. 

Regards, 

Jerry


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## Jerry McColgan (Feb 8, 2008)

The filter circuit: 










Jerry


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## Dan Pierce (Jan 2, 2008)

I know Jerry is not an Electronics expert, but the circuit could have a diode bridge feeding the sound card the DC power and the 22 ohm resistor would not be needed plus the capacitor could just be a regular 25WVDC unit. 
This is assuming the sound cards do not need to know the difference in polarity of the track power which is mostly used for horn blowing fr engine direction. 

Greg, does this make sense to you?


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## Jerry McColgan (Feb 8, 2008)

Hi Dan, 

As it works out the sound units are not polarity sensitive but since I pass the track contacts on to and from the sound cars (when sound cars are actually used) or from the sound boards (when the sound board is mounted in a loco tender, the polarity does become important. 

For this reason I have changed the wiring on the circuit making red the left track and black the right track. This is because I discovered that was necessary to keep the loco running in the right direction when running under analog track power. 

Then again I have tried so many variations that I usually don't remember from one installation to the next exactly what I did. I just put the finished loco/tender/car on the track and turn analog power on. If that works I flip analog power off and flip MTS on and if it still works I screw everything together. 

Regards, 

Jerry


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## Jerry McColgan (Feb 8, 2008)

By the way, does anyone know of a good way to cut breadboard? 

I bought all the Radio Shack dealer had but they are all too big so I will have to cut them to the minimum size for the capacitor and two resistors. 

I am planning to try a Dremel Tool with a cut off disk or perhaps a saw disk. 

Thanks, 

Jerry


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## Michael Tollett (Jan 3, 2008)

What about a razor saw? That should be able to cut clean through breadboard? 

Posted By Jerry McColgan on 07/26/2008 6:46 AM
By the way, does anyone know of a good way to cut breadboard? 
I bought all the Radio Shack dealer had but they are all too big so I will have to cut them to the minimum size for the capacitor and two resistors. 
I am planning to try a Dremel Tool with a cut off disk or perhaps a saw disk. 
Thanks, 
Jerry


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## Jerry McColgan (Feb 8, 2008)

Hi Michael, 

That is an excellent idea but strangely a razor saw is one tool I don't have. I almost bought one at the HAGRS but did not. 

On the other hand after I bought the decoders from Daryl I remembered my table scroll saw and I think that should work. 

Thanks, 

Jerry


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## Michael Tollett (Jan 3, 2008)

Hey Jerry, 

If the table saw doesn't work out, bring the breadboard to the house; I've got a razor saw there. 
Larry and I will be doing some work tonight on something, just haven't decided what yet. 

Posted By Jerry McColgan on 07/28/2008 4:25 PM
Hi Michael, 
That is an excellent idea but strangely a razor saw is one tool I don't have. I almost bought one at the HAGRS but did not. 
On the other hand after I bought the decoders from Daryl I remembered my table scroll saw and I think that should work. 
Thanks, 
Jerry


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## Jerry McColgan (Feb 8, 2008)

Hi Michael, 

The table saw worked OK (I still have all my fingers). 

I'll see if I can't get over there this evening anyway. 

Jerry 

Posted By Michael Tollett on 07/29/2008 9:40 AM
Hey Jerry, 
If the table saw doesn't work out, bring the breadboard to the house; I've got a razor saw there. 
Larry and I will be doing some work tonight on something, just haven't decided what yet.


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## Jerry McColgan (Feb 8, 2008)

After further testing I discovered that running the LGB analog sound cards from the same decoder as the loco was a hit and miss proposition. Some sound cards worked with some decoders and others did not. Eventually I discovered the basics of this filter circuit in an old LGB Telegram and I have modified it to work with Digitrax DH123D and MRC AD322 decoders. 

Wherever possible I use the MRC decoders (more power and rated for G Scale) but sometimes the MRC decoder is too large and does not fit. 










The filter circuit is small enough that it will fit in most places but could be made even smaller without the breadboard. 










The pins sticking up are where I solder the red, black, orange and gray wires. 

********************************************************************************************** 

My total cost for the MTS/DCC sound card conversions (not counting the LGB sound cards) has been $12.38 per Tender or Sound Car and includes the MRC AD322 decoder plus the resistors and capacitor as well as any sales taxes or shipping costs. Lower quantities would increase costs slightly but not very much when compared to any other alternatives. 

********************************************************************************************** 

http://www.modelrec.com/search/product-view.asp?ID=1271 

Digi-Key part numbers: 

Index Qty Ordered Qty Shipped Qty BO Qty Cancelled Part Number Customer Reference Unit Price 
USD Extended Price 
USD 
1 20 20 0 0 P1181-ND BI POLAR 0.46600 $9.32 
2 20 20 0 0 PPC22W-1CT-ND 22 OHM 0.34800 $6.96 
3 20 20 0 0 PPC220W-1CT-ND 220 OHM 0.34800 $6.96 

Your total cost is $27.76 in U.S. currency, including $2.70 postage. 

Note: the $27.76 includes parts for 20 filter circuits for a cost per circuit of $1.39. 

http://digikey.com/ 

The AD322 decoder and filter circuit will not fit in my LGB Forney tenders but I expect to be able to put a LGB 55027 or Massoth XL decoder into the Forney and either a Digitrax DH123D decoder plus filter circuit into the tender. 

If that does not work (fit) I may just put the filter circuit in the tender and use the motor output of the LGB or Massoth decoder after all. 

Jerry


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## Jerry McColgan (Feb 8, 2008)

When space is tight this circuit configuration and tiny decoder take even less space: 



Jerry


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## Jerry McColgan (Feb 8, 2008)

While I started this topic discussing LGB locos the idea (sound and power from the same decoder) has expanded for me to now include non-LGB locos and non-LGB decoders. 

My latest installation was in an older Aristo-Craft FB-1. I used a discontinued MRC AD322 decoder due to its extremely low cost but since I had spare LGB 4267s sound systems I installed one of them along with the filter circuit into the FB-1. 

This decoder is rated at 8 amps so even though it is powering two motors in the diesel I also used the same decoder to power the LGB 4367s sound system. 










The sound system is working very nicely both under analog track power and under MTS/DCC. 

This is a chuff (diesel speedup) only sound system. It does not have a bell or horn so all the decoder does with it is to give it a power that simulates analog track power. 

I used this particular sound system because I already had it and I had liked it (considering its low cost) for my analog track powered applications. 

One reason I did not use the MRC decoder diesel sounds was because it only worked under MTS/DCC while the LGB sound unit (with the filter) works both under analog track power and under MTS/DCC. 

I expect the same application (sound and power) should work with my LGB Forneys (when I get back to them) since the LGB 55027 3 amp decoder should have plenty of power to handle the sound system. The challenge with the Forneys will be to find space in the tender box for the LGB 41352 sound board, LGB 55027 decoder, speaker and filter circuit. 

Jerry


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## Jerry McColgan (Feb 8, 2008)

To show what can be fitted into small places, here is a picture of one of my home made sound cars: 










Inside can be found: 

1. Speaker (full size LGB 2 1/2" 
2. 9 volt battery 
3. Digitrax DH123D decoder 
4. Filter circuit to enable analog sound system to work under MTS/DCC 
5. LGB 4367s sound board 










The same package with a LGB 41352 sound card should fit into the tender of my LGB Forneys. 

Jerry


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## Jerry McColgan (Feb 8, 2008)

Two of the ways I use my little home made sound cars: 




















They provide a sort of generator or slug car that not only provides sound to little locos (like Field Locos) with sound but also add four additional track contacts for little locos that tend to get stuck on dirty track or going through a lot of turnouts in a switching yard. I add a wiring harness to the Field Locos to connect them to the sound cars to double their track contacts. 

It is made up from a LGB 30th Anniversary Starter Set flatcar to which I add an inverted Aristo-Craft FA-1 or FB-1 fuel tank (left over from when I bought Aristo-Craft FA-1 sound systems that came installed in a fuel tank (leaving the original fuel tanks as surplus). 










I get the extra track contacts by adding either LGB ball bearing wheels or metal wheels and Aristo-Craft wheel contact brushes left over from when I added LGB ball bearing wheels to Aristo Long Steel Cabooses (I love the "improvement" to the looks of the Aristo cabooses when they have the bright & shiny LGB metal wheels). 

Jerry


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## Trains West (Oct 4, 2008)

what i have done in the past on converting old lgb loco's is like you I have hooked the motor power to the sound power input and to get the bell and whistle to trigger I take the function output from the decoder and use it to trigger a mini relay that completes the circut on the sound board just like the reed switch does ....... in fact you can piggyback it and use both magnet / reed switch trigger and relay/ function trigger......... just remember that if you run a mini relay that it needs a anti kickback diode or it will kill the function output .......


on the wire that comes from the reed switchs on the bottom of the loco to the sound board it is black brown black ...... the brown wire in the center is the ground and on the black wires one is bell and one is whistle ..... so when the brown wire makes contact with one of the blacks that sound will happen ........


now that I posted all that I just remembered that you are running MTS with MRC decoders and I am not sure if the MTS system will trigger the MRC functions


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## Jerry McColgan (Feb 8, 2008)

Hi Scott,

Since I am using LGB Central Stations 1, 2, and 3 the MRC decoders have limited functions under serial operations so I have ended up just using the motor control output to power everything on the locos. 

The "MRC decoder project" is going to be long term as I experiment with what I can or cannot do with these very inexpensive decoders.

I now have a LGB F7A to experiment with (not one of mine) and Aristo Doodlebugs so it will be interesting to see how things work out.

Thanks for the ideas even though I did not understand all of it (I may get back to you later for clarification if I get that far).

Regards,

Jerry


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## Trains West (Oct 4, 2008)

when you say limited functions do you mean just headlight or can you make f1 and f2 happen ?

I know on some of this pictures would help I am working on a place to host what I have left ... and I will try and take more of the stuff I am working on as I go


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## Jerry McColgan (Feb 8, 2008)

Posted By Trains West on 10/06/2008 10:35 AM
when you say limited functions do you mean just headlight or can you make f1 and f2 happen ?

I know on some of this pictures would help I am working on a place to host what I have left ... and I will try and take more of the stuff I am working on as I go 





Hi Scott,

I am unable to tell just what does or does not work with the MRC decoders. I've been told that they will not function with Serial commands (such as with MTS Central Station 1's) but my friend who has a LGB White Pass diesel that I installed a MRC decoder tells me he can run the loco, turn the lights on and off and ring the bell as well as have the sound running.

I don't know enough about MTS/DCC to make any definite statements about what can or cannot be done. I just try stuff and see what works or does not work.

Sometimes things work that I did not expect to work. I cannot explain why or why not.

On my personal locos all I do with the MRC decoders is to wire them between the track contacts and where those wires feed into the loco so the locos function pretty much as if they were running under analog power (lights dim along with motor slowing down etc.).

For some people MTS/DCC represents the ability for one user to run multiple locos. In my case I run analog track power for myself but switch to MTS when I have multiple visitors so MTS gives me multiple operator capability more than multiple train capability. I still use analog sound systems (LGB 4135 type sound cards) that are modified to work under MTS/DCC.

Regards,

Jerry


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