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Non-Sound Decoder and Light Options for Stewart/Kato F Units

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Non-Sound Decoder and Light Options for Stewart/Kato F Units
Posted by Attuvian on Saturday, January 12, 2019 7:25 PM

I picked up three little used Stewart/Kato F units (2As and a B) recently that may well have never been opened up.  I would like to consider doing them up with non-sound decoders, preferably TCS or ESU, but I can wiggle on the maker, especially if I can get good performance at a cost less than an ESU board.

I dropped into one of my LHSs this afternoon and the guy showed me a couple of Digitrax options, one a board that was definitely not a drop-in and another that was an encased "thumbnail" sized assembly with the associated cable and plug to be hard wired.  Sorry I didn't write down the numbers, but that may not be relevant at this point.  Before I amble across town with one of these locos in hand as a visual for him, can I get some suggestions here?  For starters, the Stewart P/N for one of the A units is #9160.  Here's a photo of what's installed:

 

(You Stewart guys will know what this is.  Motor connections are by tabs that contact the two long buss wires that attach to the truck pick-ups at either end.)

BTW, when I dropped these three onto the club (DCC) layout, they ran nicely but a bit slow, even with the Digitrax throttle cranked up all the way.  All tracked at similar speeds across the full range of the throttle. I suspect that's because of the gearing but it might be that the motor control is limited under DCC.  Additionally, I found that the intensity of the headlight was somewhat less than thrilling.  I don't think it varied but my memory over the last three weeks is rather questionable.  Can I expect both of these issues to change with a decoder installation?  Should I consider replacing the lamp (which I'm pretty sure is an incandescent bulb)?

Thanks!

John

 

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Posted by BigDaddy on Saturday, January 12, 2019 8:08 PM

I have a Stewart F3, which took me 25 years to complete, but I put in a loksound select board.  I realize that is not what you want to do, but that is what I did.  I also used a 3 mm led and glued it to the back of the plastic headlight with caulk, and I think a bit of that metal light tube, with Dap 230. 

I have a friend with a milling machine, one should always have a friend with a lathe and a milling machine, and milled out the stern to have space for a speaker.

Led's last forever, so definitely replace the bulb.  If you are converting a fleet of older DC loco's like I did, sticking to one brand of decoder is worthwhile.  ESU does make non sound decoders, but I am not up to speed in offering you any advice.

Henry

COB Potomac & Northern

Shenandoah Valley

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Posted by tstage on Saturday, January 12, 2019 8:20 PM

John,

Digitrax makes good decoders.  However, I'm very partial to the excellent motor-control of the TCS decoders so that's what I would recommend.

If it's a Stewart FT, you'll want the MC2P-UK.  If it's an F3/F7, you want the MC2A - 3.5"[harness].

I don't believe the decoder comes with on-board resistors so you will need to add 1K resistors for the front headlight(s) - i.e. if you choose to install 3mm LEDs.  When it comes to headlights, I always prefer LEDs.

Tom

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Posted by Attuvian on Saturday, January 12, 2019 8:32 PM

tstage

If it's a Stewart FT, you'll want the MC2P-UK.  If it's an F3/F7, you want the MC2A - 3.5"[harness].

Tom

 
Tom,
 
Both of the As are F7s, the B unit is an F3.  All have the same chassis work and guts.
 
John
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Posted by tstage on Saturday, January 12, 2019 8:34 PM

John,

Here's a link to the TCS website showing a T1 decoder install in a Stewart F3 with the kind of lightboard you show in your photo above:

http://tcsdcc.com/installation/ho-scale/stewart-f3a-all-phases/t1

Looks pretty straightforward...

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by Attuvian on Saturday, January 12, 2019 11:07 PM

tstage

John,

Here's a link to the TCS website showing a T1 decoder install in a Stewart F3 with the kind of lightboard you show in your photo above:

http://tcsdcc.com/installation/ho-scale/stewart-f3a-all-phases/t1

Looks pretty straightforward...

Tom

 
Tom,
 
Small world: had a TCS T-1 recommended for my Athearn Genesis MT-4, too.  Which runs quite nicely.
 
I note that the pics on the TCS site, and especially the last one, do not show the exact same set up for the light.  Which is probably no big deal.  I'll wait for some more responses on that account.  I'm presupposing that the leads to be soldered to the bulb or LED will have a constant voltage.
 
John
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Posted by rrinker on Saturday, January 12, 2019 11:34 PM

 Only thing I see different on the TCS page is that they put an LED and resistor in place of the bulb. Which is always a wise choice.

                                       --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by tstage on Saturday, January 12, 2019 11:45 PM

That particular board is a new one on me, John.  None of my Stewart F-units came with one of those.  All mine have a regular PCB board for the lighting.  And some even came with LEDs already installed and a mounting clip to align it to the headlight lens.

I'm guessing that the headlights inside the plastic shroud are incandescents.  So, if you do install LEDs, you'll need to add the 1K resistors.

You might be able to mount the LEDs inside the shroud...or you could use a #32 (0.116" OD) drill bit to drill out a 1/4" deep hole in the front lens.  The LED bulb should press fit nicely into the hole and not require any gluing for it to stay in place.  And if the LED should ever go bad, it can be removed with a little-to-moderate pressure.  Whenever possible - I much prefer mechanically securing an LED over gluing it.

Tom

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Posted by Attuvian on Sunday, January 13, 2019 12:09 AM

tstage

That particular board is a new one on me, John.  None of my Stewart F-units came with one of those.

Tom

 
Tom,
 
"New"/old, perhaps.  I suspect my Fs are from quite a while ago.  Thanks for the tips on the LED installation.  If I go with the TCS I'll probably get the standard version rather than the T1-LED, which looks to be five or six dollars more.  Yikes.  How much can a 1K resistor cost?
 
BTW, what wattage for these resistors?  Haven't bought a resistor in 40 years, the old Allen-Bradley jobs that you could carefully grind to tweak (up?) their values.  Those resistors classify these days as archeological finds!
 
John
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Posted by tstage on Sunday, January 13, 2019 12:10 AM

1/4W should be just fine, John.  Here's a link to a rear headlight installation I did on a Walthers SW1 switcher a few years back:

http://www.newyorkcentralmodeling.com/rear-headlight

I used 5/32" OD styrene tubing but it still incorporates the #32 drill bit for the ID of the tubing...

Tom

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Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by Attuvian on Sunday, January 13, 2019 12:13 AM

Thanks.

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Posted by rrinker on Sunday, January 13, 2019 11:00 AM

T1-LED shows the same MSRP as the plain T1. T4 and T4-LED are a few dolalrs more, but those have extra functions.

                              --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by gmpullman on Sunday, January 13, 2019 11:14 AM

Attuvian
BTW, when I dropped these three onto the club (DCC) layout, they ran nicely but a bit slow, even with the Digitrax throttle cranked up all the way. — Additionally, I found that the intensity of the headlight was somewhat less than thrilling.

Possibly because you were running a DC engine on DCC "zero-bit stretching" mode. I believe the engine was only seeing half the voltage. I hope you didn't have tour engines on the DCC rail for very long.

https://sites.google.com/site/markgurries/home/technical-discussions/dc-loco-on-dcc/dc-locomotive-damage-risk

That is one of the Kato designed stewart locos.

Have you looked at the TCS install pages?

http://tcsdcc.com/installation/ho-scale/stewart-f3a-all-phases/t1

They can be helpful.

Good Luck, Ed

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Posted by Attuvian on Sunday, January 13, 2019 2:31 PM

gmpullman
Possibly because you were running a DC engine on DCC "zero-bit stretching" mode. I believe the engine was only seeing half the voltage. I hope you didn't have tour engines on the DCC rail for very long.

https://sites.google.com/site/markgurries/home/technical-discussions/dc-loco-on-dcc/dc-locomotive-damage-risk

Have you looked at the TCS install pages?

http://tcsdcc.com/installation/ho-scale/stewart-f3a-all-phases/t1

They can be helpful.

Good Luck, Ed

 
Ed,
 
The locos were probably run no more than two or three minutes each so I should be okay.  I may set up a test track later today to verify that they've survived.  Thanks for the informative link and post that you included above.  Very sensible.
 
I like the TCS install photos.  Can't be more plain - or more simple.
 
John
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Posted by rrinker on Sunday, January 13, 2019 2:36 PM

 Of course, since they are using a wired decoder, the same instructions apply to any similar decoder. So you can use whatever one you want - but TCS decoders are really good.

                                --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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