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What decoder is best for older Stewart F Units?

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  • Member since
    October 2004
  • From: Colorful Colorado
  • 8,639 posts
Posted by Texas Zepher on Tuesday, April 1, 2014 1:02 PM

mobilman44
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.

I would like to see a picture of that.  I always use the DASR or Digitrax DH165KO for the older Stewarts.   

  • Member since
    February 2002
  • From: Reading, PA
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Posted by rrinker on Tuesday, April 1, 2014 3:05 PM

 See the link I posted from TCS. These are REALLY old Stewart F units, with Kato drives and the grey plastic Kato 'circuit board". Unlike other Kato locos liek the RS/RSC series sold by Atlas, these F units have screws holdign the palstic to the chassis. The Atlas/Kato locos have a psir of clips, which clip into the board repalcement decoders like the DASR, so I suspect there's nothign there to hold the board in place. I suppse you could double-side tape it on top fo the motor.

Personally I direct wire whenever possible just because I'm a cheap Dutchman. Sticking with NCE, the D13SRJ is cheaper then a DASR, or with Digitrax, a DH165 is cheaper than a DH165K0. My F units are all newer ones that have the actual electronic circuit boards, but I remove those and hard wire even so. The Stewart/Boswer circuit boards are fairly simple and easy to figure out, but thsi is not true of all brands, and rather than mess around with figuroung out if the resistors for DC stay in teh circuit or not when just plugging ina  decoder, I avoid it all and hard wire. For sound, n contest, removing all facroty junk makes the most space for the biggest speaker and enclosure.

              --Randy


Modeling the Reading Railroad in the 1950's

 

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

  • Member since
    September 2003
  • From: Southeast Texas
  • 5,449 posts
Posted by mobilman44 on Tuesday, April 1, 2014 4:46 PM

While awaiting the arrival of the decoders & LEDs, I stripped down two of the units to "lube and tune" them.  The Kato motor/chassis just amazes me.  They have been sitting in a box for about 7 years, and before I oiled them up they ran just fine on the test rollers.  Afterwards, I was very pleased with the noise free operation, and of course the low speed ability.   I'm glad I kept these, and look forward to getting them wired up.

ENJOY  !

 

Mobilman44

 

Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central 

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, April 1, 2014 4:55 PM

rrinker

 See the link I posted from TCS. These are REALLY old Stewart F units, with Kato drives and the grey plastic Kato 'circuit board". Unlike other Kato locos liek the RS/RSC series sold by Atlas, these F units have screws holdign the palstic to the chassis. The Atlas/Kato locos have a psir of clips, which clip into the board repalcement decoders like the DASR, so I suspect there's nothign there to hold the board in place. I suppse you could double-side tape it on top fo the motor.

Personally I direct wire whenever possible just because I'm a cheap Dutchman. Sticking with NCE, the D13SRJ is cheaper then a DASR, or with Digitrax, a DH165 is cheaper than a DH165K0. My F units are all newer ones that have the actual electronic circuit boards, but I remove those and hard wire even so. The Stewart/Boswer circuit boards are fairly simple and easy to figure out, but thsi is not true of all brands, and rather than mess around with figuroung out if the resistors for DC stay in teh circuit or not when just plugging ina  decoder, I avoid it all and hard wire. For sound, n contest, removing all facroty junk makes the most space for the biggest speaker and enclosure.

              --Randy

 

When you hard wire, such as the T1-LED, how do you keep that plastic packet from interfering with the motor and diriveshaft?

Do you put those original boards back into place first?

Rich

Alton Junction

  • Member since
    November 2007
  • From: California
  • 2,388 posts
Posted by HO-Velo on Tuesday, April 1, 2014 7:53 PM

Mobilman,  

As you maint. the drive train of your Stewart Kato drives check the geared wheels sets for any cracked axle tubes.  I found several cracked ones over the years and as of a few months ago Kato still stocks replacement wheelsets.  

If there were enough demand NWSL would do some aftermarket wheelsets for these drives, they machine and bore solid rod for their geared wheelsets.  Regardless of the wheelset issue I still adore the smoothness of my vintage Kato drives.

regards, Peter

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Tuesday, April 1, 2014 8:22 PM

richhotrain
 
rrinker

 See the link I posted from TCS. These are REALLY old Stewart F units, with Kato drives and the grey plastic Kato 'circuit board". Unlike other Kato locos liek the RS/RSC series sold by Atlas, these F units have screws holdign the palstic to the chassis. The Atlas/Kato locos have a psir of clips, which clip into the board repalcement decoders like the DASR, so I suspect there's nothign there to hold the board in place. I suppse you could double-side tape it on top fo the motor.

Personally I direct wire whenever possible just because I'm a cheap Dutchman. Sticking with NCE, the D13SRJ is cheaper then a DASR, or with Digitrax, a DH165 is cheaper than a DH165K0. My F units are all newer ones that have the actual electronic circuit boards, but I remove those and hard wire even so. The Stewart/Boswer circuit boards are fairly simple and easy to figure out, but thsi is not true of all brands, and rather than mess around with figuroung out if the resistors for DC stay in teh circuit or not when just plugging ina  decoder, I avoid it all and hard wire. For sound, n contest, removing all facroty junk makes the most space for the biggest speaker and enclosure.

              --Randy

 

 

 

When you hard wire, such as the T1-LED, how do you keep that plastic packet from interfering with the motor and diriveshaft?

Do you put those original boards back into place first?

Rich

 

THe decoder I usually attach across the top of the motor with kapton tape. Wires? There's not enough loose wire to get tangled in anything. It's not hard to work int he small space - these decoders have 9 pin plugs so I work with just the wire harness, no decoder blob to get int he way of soldering. After a bunch of different locos I'm pretty good at figuring how much wire to leave, but if it's a different one, I sort of mock it all up so see what has to go where before cutting any wires to length. On some I've used parts of the factory board as a mount - a Walther's FA, I forget the exact deal inside there but I cut off a short bit of the factory board that screwed to the very rear of the frame and used that as a shelf. Even though the bluw and white wires ran the length of the loco to the LED in the nose, it's not droopy enough to get caught in the drive shafts. At least, it hasn;t in the nearly 10 years it's been since i put a decoder in it. And a few years ago opened it up to swap in a current T1 with BEMF, that old one was before they had BEMF in their decoders.

 Protos, everything comes out, but they have a solid top to the frame so there's really no way wires could get caught int he moving parts. I actually have no AThearn BB so I'm not sure how I'd do those, maybe use miniature connectors and attach the decoder to the shell. Atlas/Kato I've done in the past I did use the TCS A series boards, all the ones I currently have do not have decoders yet, they need details and paint first, and at least some of them are getting sound. My brass RS3 has the decoder attached to the body with micro connectors, it came that way, I just swapped the decoder but it needs some cleaning up and the drive reworked, and I plan on putting sound in that one too.

             --Randy

 


Modeling the Reading Railroad in the 1950's

 

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

  • Member since
    October 2004
  • From: Colorful Colorado
  • 8,639 posts
Posted by Texas Zepher on Tuesday, April 1, 2014 9:03 PM

rrinker
See the link I posted from TCS. These are REALLY old Stewart F units, with Kato drives and the grey plastic Kato 'circuit board".

Hmmm I think mine are even older because they did not have the DCC 8 pin socket, at least not that I remember.   And yes I seem to remember using double sided foam sticky tape to mount the new decoder on top of the old circuit board.  Funny how many variations on a theme there can be.

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