# USA Hudson



## Kenny (Feb 15, 2008)

Has anybody out there converted their USAT Hudson to DCC? If so, has anybody experianced any kind of problem with the smoke unit, either wired or not wired through the decoder?


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## Greg Elmassian (Jan 3, 2008)

There is an intrinsic problem with smoke units in the Hudson. For sure the first release, and maybe the second, the TAS smoke units need to be insulated from the rest of the locos. 

This was either not done at all, or poorly done. When the metal body of the TAS unit contacts the other metal bits in the loco, it normally damages the TAS smoke unit. 

The TAS people were pretty worked up over this, because many people blamed the unit, and thus their reputation. I got this personally from talking to an engineer at TAS. 

The "DCC" version of the unit had something different, I know it came with a full wave bridge rectifier on the input, which is typical in DCC stuff. 

Wiring through decoder, make sure you have enough current capability in the decoder to handle it. 

I'd test it on DC first. Be SURE of polarity before testing. 

Regards, Greg


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## Kenny (Feb 15, 2008)

Hello Greg, how would you go about insulating the smoke unit from the body?? I converted my Hudson to DCC using an NCE 808 decoder. I did not wire the smoke unit through the decoder. For some reason or another the bridge rectifier on the smoke unit fried. I sent it to Charles Ro and they replaced the rectifier. When I received the unit back, I wired it into the NCE decoder, + to common and - to F5. When I powered it up it smoked for a second and then died. I rewired back to the original wiring and nothing. I sent it back to Charles Ro and now they are insinuating that the unit's failure has something to do with my NCC conversion. What do you think???


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## Kenny (Feb 15, 2008)

Gregg, I meant DCC conversion, my bad!


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## Greg Elmassian (Jan 3, 2008)

It sounds like the standard problem, smoke unit not insulated from the mounting. Fiber insulator, styrene, anything not conductive. The bridge rectifier is a dead giveaway. 

When you did the conversion to DCC are you SURE that no part of the body/frame was connected to anything? I'm pretty sure that this is the problem. 

Now the smoke unit is fried, and the original problem is probably still there. 

My opinion is that the "factory supplied incorrect installation" caused both failures. The problem is that I don't believe that USAT has acknowledged the original problem. 

You might be stuck. TAS is also gone now, no longer in business. 

You may be forced to buy another unit, and it might only be available from USAT. 

By the way, I meant insulate the smoke unit from the mount inside. Do you have a picture of it in place? 

Regards, Greg


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## benshell (Oct 1, 2008)

Can I ask for a little clarification? I don't have a Hudson yet, and I'm just learning about DCC too, but I'm trying to read and understand all I can about what to do (and not do). I've re-read this thread twice trying to understand it all, and what I think I'm missing is how SHOULD the smoke unit be wired?


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## Greg Elmassian (Jan 3, 2008)

It's not wiring, it's that the body of the smoke unit is metal, and apparently connected to the circuit. Grounding the body of the smoke unit can cause a short circuit, damaging the smoke unit. 

The body of the smoke unit must be insulated from the rest of the loco. 

Greg


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## Kenny (Feb 15, 2008)

Greg, USAT now has my TAS smoke unit. You are right about the grounding issue. I mentioned this to Charles Ro and they said they had never heard of this problem. I am in the process of either getting my unit repaired or replaced and unfortunately, the only place where you can get this unit is USAT. If and when I get the smoke unit back, I will insulate it from the engine. No picture, the smoke unit is in MA.


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## Greg Elmassian (Jan 3, 2008)

Just to re-iterate, I have spoken to several people at TAS, and they were all upset because they were getting a bad rap. Two different people told me on two separate occasions that they told USAT that the units could not be "grounded" to any part of the loco, since the metal housing of the TAS unit is connected to power. 

I hope you get a new unit. They are nice units, and have a volume of smoke second only to the MTH (unobtainable now) and the Massoth ($200). 

I can look at mine, which is set for DCC, and see if there are any differences. The picture on my site (search for "smoke units") of the TAS is mine. 

Regards, Greg


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## Kenny (Feb 15, 2008)

Greg, thanks for all the info on this. USAT is insinuating that the reason for the problems with the smoke unit goes back to my DCC conversion. As of right now, USAT has my smoke unit. I think they are holding it hostage. If and when I get the unit back, I will make sure that it is insulated from the loco body. Did you wire your TAS unit through a decoder? It is too bad that USAT does not give the grounding issue any credance at all, they just say they never had a problem with it! The Hudson is a great loco and it looks best when all the bells and whisles are working properly.


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## Greg Elmassian (Jan 3, 2008)

While all things are possible, the first failure was before the DCC conversion. 

The only thing the decoder could do is either fail open (no voltage sent to the TAS unit), or fail shorted to ground (full voltage to the TAS unit). I cannot see how that could possibly damage the unit. That's my opinion. 

Again, you may be stuck, and not much you can do, except remind them of that. 

I have not installed my TAS unit permanently yet, but I would normally use a small relay to avoid excessive draw on the decoder. I have not measured the current on the TAS unit, but most get over the 100 milliamps the decoder is capable of. 

I'm sorry you are in this predicament, but saying they never had a problem is BS, just ask 10 Hudson owners (as I have) and you will most llikely get 8 that know about it. 

I'm surprised more Hudson owners have not chimed in. My most recent contact with a Hudson owner was in person at the SWGRS show, the guy I talked to had 3 of them, I saw two right there. He definitely knew about the smoke unit problem, but did not know the cause. TAS was a small company, and what could they do? USAT was their customer, so blasting USAT would have been blasting their customer. They were stuck. Thus the great unhappiness with the situation. They were "stuck" too. 

Regards, Greg


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## Kenny (Feb 15, 2008)

Do you know of any compatable replacement for the TAS unit? Something that would not take major mods to the loco. If and when I get the smoke unit back, do you have any recommendations on how and where,exactly, to insulate the unit from the loco? I am pretty sure I could figure it out but I do not want to experiment with this thing. If I wired it to a function on the D808, would the decoder handle it? As far as USAT's failure to acknowledge this problem; this is the second time I have gone down this road with them. The first time involved a PH Hobbies sound unit. They insisted there was nothing wrong with it and after returning the engine to them several times, they finally gave in and refunded my money. I believe PH Hobbies is no longer in business! It would be good business for them if they would acknowledge that sometimes mistakes are made.


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## Greg Elmassian (Jan 3, 2008)

If the loco were mine, I would get a Zimo decoder, the MX69x, decoder and sound. Then I would make the chuff contacts reliable and control the chuffs from there. Then you could use the TAS or an MTH unit and have the smoke "puffs" exactly syncrhonized to the drivers motion. That would be my top configuration. Lots of smoke, synchronized to the drivers. 

If you can't get a working TAS or MTH unit, then buy a Massoth, which has a chuff input line, is DCC compatible, and run it from your "chuff switch". 

You keep asking about the D808 being able to handle things. You need to look at the D808 specs, see what it has for current handling. You need to get the smoke unit specs or measure current yourself. Trust no one! Honestly, if you are wanting to do the install, you need to have the ability to do these basic measurements. I've given you my personal opinion on connecting already, on an expensive loco, I would take a conservative approach, make things dead reliable. 

PH hobbies gone, yes. 

On manufacturers acknowledging mistakes, USAT is not alone or unique, I can give you equivalent stories about Bachmann and Aristo. 

The thing here is to cut your frustration and move on, it sucks, I know, but it is what it is. 

Regards, Greg


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## Kenny (Feb 15, 2008)

I am frustrated, you are right! Thanks for the help and info.

Ken


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## Dan Pierce (Jan 2, 2008)

At Train-Li we added a Zimo MX690V to several USA trains steam engines and converted USA's smoke unit to operate with controlled smoke. 

Only the V version can control smoke unit heater elements and motors.


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## Greg Elmassian (Jan 3, 2008)

I did not mention that smoke unit because it is nowhere near the output volume of the TAS, MTH or Massoth. I have heard another rumor that the USAT fan-driven units are out of stock also. 

But Dan underscores an important point, and I will elaborate, the Zimo actually has outputs that can modulate the fan for chuffing or a diesel and outputs to modulate the heating element. 

These outputs are PWM. 

Quite sophisticated. More programming than some simpler solutions, but very customizable. 

Regards, Greg


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