What decoder is best for older Stewart F Units?

Model Railroader Electronics and DCC
1

Hi!

I have detailed an older Stewart ABBA F7 consist and bought (couple of years ago) 4 NCE DASR decoders (board type) to install in them. Well, I finally got around to wanting to install the DCC decoders.

Upon pulling the shells, I find that the DASR decoder boards are not appropriate for the workings that my locos have. What I really need is the “package type” decoder with the wires attached.

My decoder guide books are out of date, and I need your help in finding the right one that is now available.

Also, as long as I’m here, what type LEDs and resistors are needed?

Thanks all!

2

If you don’t want sound this decoder works good. My Stewart is an early 1990s and the innards are the same as the Loco depicted in the following link. I kept the orig. bulb as per the instructions, but it finally burned out. Guess I’ll look into replacing the bulb with an LED sometime in the future.

regards, Peter

http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/HO_Scale/Stewart/Stewart%20F3A%20Phase%20I/Stewart_F3A_I.html

3

The TCS “T1” will obviously work. But looking up a “T1” yields various kinds and model numbers. I want one with the wiring attached, and am not certain which model to order.

4

Regular T1 is the basic decoder with wires. The wires are actually on a 9 pin plug so the decoder can still be removed. All the other suffixes are different forms of harnesses with 8 pin plugs on the end, exvept the T1A, which is the basic T1 with no harness (for locos like newer Athearns that have a 9 pin plug - since you don;t need the plug and wires with those, the T1A is a buck or so cheaper).

–Randy

5

For my Stewart I used TCS T1 1021 decoder, came with plug in wire harness

regards, Peter

6

The TCS link given earlier was for a Stewart FT. Below is a lonk to the TCS installation photos for the early Stewart F7.

http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/HO_Scale/Stewart/F7A%20Early%20Phase%20I/Stewart_F7A_Early_Phase_I.html

Good luck!

7

I was too early on my purchase date, purchased my two Stewarts new, F9A unit instruction sheet dated 10/97. B unit purchased soon after F unit. The F9A stock#9310 and F3B stock#8041 have the same innards other than the B unit has no light pipe or bulb. Innards of my two models are the same as the ones in the link I posted earlier.

The T1 install in the F9A was my first and went smooth following the instructions in the link, just wish I had installed an LED at the same time. Have yet to install decoder into the F3B. These models have always been great runners, might be my imagination, but it seems the F9A runs even better with DCC.

regards, Peter

8

If in doubt, your best bet is to contact TCS and ask for their recommendation.

But the following information may be helpful to you.

Greenway Products installs the TCS MC2P-SH decoder and says that this decoder is “recommended by TCS” for the older Stewart F7.

http://greenwayproducts.com/storeroom/Electronics/decoders.html

Here is a link to the TCS MC2P-SH decoder on the TCS site:

http://tcsdcc.com/public_html/Zen/index.php?main_page=index&cPath=4_15

Hope this helps.

Rich

9

Hi,

My 4 units are the type posted by HO-Velo - with the grey plastic piece on top, instead of the green circuit board as indicated for the other version of the Stewarts. It looks like the T1 1021 is what is used in the demo.

10

Those are the Kato drive ones, the grey plastic ‘circuit board’ is the giveaway. I’d just do the hard wire method and remove the plastic board. FT or F3 or F7, the Kato guts are all pretty much the same, though this seems a bit overly complicated: http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/HO_Scale/Stewart/stewart%20early.htm

Chopping the plastic in half to save the light tube - well, I guess that’s one way to keep from lighting up the entire cab, but painting the sides and back of the LED will do the same.

–Randy

11

Anyone have any thoughts on the differences and benefits of the T1 compared to the MC2P ?

Is one better than the other?

Rich

12

I can see why one would prefer a hardwire and not rely on the pick-up wire friction clips. I kept the grey plastic board/ friction clip to copper rod set-up thinking that it might make for easier removal of the truck assemblies for maint. Install was made over a year ago and no pick-up problems yet, but never did experience any pick-up problems with these units pre-DCC.

regards, Peter

13

Yes, the T1 is cheaper.

Otherwise, they are functionally identical, other than physical size. Nice thing about TCS, the functions and features are stabilized across their line of decoders. Difference are all in physical form factor and total number of functions a given decoder has.

I used an MC2P in my 44-tonner, and also in Proto S2 switchers, but when there’s room for the bigger T1 I just use those because they are cheaper.

Might matter, they have MC series with keep alives now, and an MC with KA might fit where a T1 without KA fits.

–Randy

14

Thanks all for your input. It looked to me like the TCS T1 was a good choice but I contacted TCS to verify. “Dave” at TCS suggested the T1 basic or the T1 LED as it had the built in resistors for LED application. Soooo, I ordered 4 of them, and look forward to getting on with the long delayed project.

Thanks again!

Mobilman44

15

I use the T1’s so much that a pack of 4 of them is a staple item on my Christmas list each year. I have about 5 on hand right now. Note sure what’s going to happen int eh near furute, since I am moving soon, and it will be at least another eyar until I get a decent track plan designed and might be ready to build. In the meantime I might end up getting more locos completed, or I might just be too busy with hosue things to do any railroad stuff. I’m probably not doing my usual summer show with the club. Might give me the chance to whittle down some of the project list - besides what’s on my web site I probably have 4-5 more things I never bothered to add there.

–Randy

16

The existing bulbs are in metal tubes. The bulbs are just a tad over 1mm. What color/type LED will work?

Also - forgive my ignorance - what would happen if I just reused the bulbs?

17

Good grief, my measurement is garbage. I didn’t zero the micometer and got a 1 mm reading. Yikes, I should have known better. The actual measurement is 3 mm.

With that said, what will work?

18

Mobileman,

I reused the orig. bulb, but it failed a couple months ago. Don’t know that the failure had anything to do with DCC conversion or just bulb life. The loco had a lot of DC service hours having owned it for nearly 20 years. If you’re wanting to use the metal tube, maybe a 3mm LED will fit the tube, if not maybe you can fab up a tube. Two popular colors of LED for loco headlights are golden white and sunny white, I’ve yet to decide what color I’ll be replacing my failed bulb with. TCS suggests a 680ohm resistor with their 3mm LEDs and they also have a color sample on the LED portion of their website.

regards, Peter

19

Mobileman, Just miked up a thru hole flangeless 3mm LED that I have on hand. .121 dia.

regards, Peter

20

Also miked up a 3mm LED with flange, LED dia. .118, flange dia. .132

Peter