I have an older Stewart F7A&B set, both powered. I'd like to add a DCC decoder to them. However, instead of a PC board with an 8-pin receptacle as in the later models, these have a gray plastic 'trough'-type board with thin copper wires running to various components, with thin black wires connecting to the wires which come from the powered trucks. The board is held down with two small screws which appear to be spaced similar to other decoders I have used.
Looking at various decoders, I have narrowed it down to the Digitrax DH165KO, which looks like it would accommodate the black wires to the trucks, and would accommodate the same mounting pattern.
Just wanted to see if anyone would agree with using this decoder. I also want to keep the same head light bulb if possible. Any ideas out there?
Many thanks!
I have done it that way, but not fond of Digitrax decoders in gen. but also hardwire in either NCE or TCS decoders, check out this link
http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/Stewart/Stewart%20F3A%20Phase%20I/Stewart_F3A_I.html
This is the method I now use on these. good luck
I have yet to do my 1st conversion. I have a Stewart F3 that sounds like yours and looks like the picture of a TCS conversion in the previous post.
The usual advice is to go LED because they last forever. it gets tricky because some decoders have resisitors, some do not. Some LED's are 12 v and some are not, so you have to have the right combo.
Henry
COB Potomac & Northern
Shenandoah Valley
I use these NCE decoders in my Stewart/Kato F units. They replace the plastic board in the Stewarts.
I use the copper conductors from the Kato board to make extensions for the power wires from the trucks. I solder the copper conductors to the NCE decoder and then solder the pickup wires to the extensions. I even leave the connector on the wires.
The front of the Kato chassis is the tappered end. If you put the decoder in with the head light connections facing the tappered end, then all your connections will be correct...red and black for power and orange and gray for the motor.
I have about 30 of the Stewart/Kato F units. Some I bought new in the late 1980's, some I bought new last week from EBay. All are smooth running engines.
I'll try to get some pictures up tonight.
These are great running locos. I have the B&M F7A&B units. They don't have the Mars lights, just the nose headlights. I have used the Digitrax DH165KO decoders in the past and they work just fine. I understand that the connections for lights have built in resistors for bulbs....which to me, means that you don't need to add discreet resistors for the bulbs (?).
In this poor picture, you can see the power extensions I made from the copper conductors on the Kato power board. The extensions are then soldered to the NCE decoder. The power leads from the trucks are connected to the extensions and then soldered.
The motor leads are tucked under the loops that are on the NCE decoder, then soldered.
The head lamp leads are soldered to the decoder.
There is a small piece of wood holding the rear of lamp holder up.
Sorry about the poor picture.
bandmjim, thanks for the post of the TCS instructions.....great photos!
I take it that one doesn't need to add resistors to the headlight? I imagine the decoder has them built into the decoder?
Thanks for your input. -Al
Having resisters for LEDs depends on the decoder. Check the instructions for whatever one you use.