Decoder Selection Questions - Share your knowledge

[larak]

Hi guys,  I am soon to take the leap to the DCC side.  My issue is that I have several locos without decoders that I need to retrofit. All H0 scale.

I would like suggestions for which decoders will fit (and work well with) the following locos.  Back EMF is desirable:

"DCC Ready"

P2K  S3 switcher,   sound not necessary due to size

P2K  S1 switchers     sound not necessary due to size

P1k  F3A and F3B units      sound not necessary but keeping options open

Non-DCC Ready IHC (looking for a good source for 4 pin plugs/connectors too)

Hudsons (sound would be nice),      2-6-0,    4-4-0

The IHCs, while not as pretty as my BLIs, run really well and are like old friends. Plus converting them will save me from having to purchase five new locos.

Thanks in advance for all suggestions and experiences. Tutorials welcome too.

Karl

[cacole]

Train Control Systems decoders should fit into all of the ones you mentioned.  Take a look at their web site, where they have pictures of user installs in many different locomotives.

For sound, my first choice is an ESU LokSound Select decoder.

https://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/HO_Scale/HO_Search/search.html

 

 

[richhotrain]

A word of warning on the P2K S1 and S3 locos.

Although they are stated to be DCC Ready, they are not due to a wiring flaw.  One of the wires, an orange one is grounded to the frame, so it must be relocated elsewhere on the motor brushes.  Otherwise, in the event of a derailment, there is a good change that the decoder will get fried.

Rich

[Guy Papillon]

I recently converted some locomotives like the one you named to DCC.

P2K S-3:   TCS M1P-15 due to lack of space.  Don't forget to isolate the motor from the frame.

P1K F3A & F3B: TCS LL8 

I am very satisfied with those decoders. Good slow speed performance.

 

[Iansa]

For sound I would suggest TCS WOW sound for steam.

Non sound I only use DCCconcepts or TCS both are BEMF.

Cheers

Ian

[rrinker]

 Ditto on the S-1 and S-3, the motor needs to be isolated from the frame to prevent a derailment from frying the decoder. These are tricky, as they will run fine as-is, the motor IS isolated from the track pickups. But should it derail and a wheel be pushed up into contact witht he frame, you are connected the track power to the motor output of the decoder and for a brief instance you will have realistic Alco smoke.

 For many other installs, see the TCS web site. Even if you end up not using their decoders, the install pictures are a great help in figuring out how to do things. For all my non-sound locos, I DO use TCS, they have many shapes and sizes, though I most always hard wire any decoders and use the basic T1, switching to the MC series where space is tight (44 tonner, Proto S-1). Board repalcements only for the Atlas/Kato locos since space is tight there as well. The main point is, iof the loco already has distinguisable wires coming from the truck pickups and the motor, it's just as easy, and a bunch cheaper, to use a plain wired decoder than the special board shapes. I also always repalce any light bulbs with LEDs and resistors, once I get a loco running I don;t like to take it apart if I can help it, I try to handle my equipment as little as possible, something always gets dinged up, either added detail or the handrail paint.

https://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/HO_Scale/HO_Search/search.html

for the HO installs.

              --Randy

 

[larak]

Thanks everyone. After some research and fast / friendly communications from Dave at TCS, I will be trying their decoders. Do anyone know the values of typical keepalive capacitors? "It's proprietary information". That will save me the trouble of putting one on the meters. I plan to buy most of the decoders without and add my own later if needed. Karl

[rrinker]

Most supercaps are around 5 volts, so you need 3 in series for 15V, and you need to make sure you never exceed that, caps fail in a rather spectacular fashion if overvolted. It looks like most of the KA units from TCS have 6 caps, 2 sets of 3 in series, each set of 3 parallel to the other to add capacitance. They do NOT get connected tot he track power, they get connected between the positive AFTER the rectifier (which is also the blue wire) and the negative side of the rectifier, which you have to locate by examining the circuit board - soldering a wire to the appropriate point. Which voids the decoder warranty. You would also want to hook up a resistor and diode to reduce current inrush. See Marcus Ammann's site for hints: http://www.members.optusnet.com.au/mainnorth/alive.htm

 My home layout, I never have problem with stalling or even blinking lights. The club layout - everyone runs at least 2 units in consist just to get over the dead spots between modules. I was going to get a pair of KAT1's to replace the T1's I have in the two locos I use the most, to see how they work. Plenty of room in the Proto Geeps, since I repalced the factory board completely, and since the T1 has a 9 pin plug and the KAT1 has a 9 pin plug, it's just a matter of popping one off and putting the other on. The combined size of the external KA and the newer decoders with the plug for them is a bit larger than the all in one KAT1.

                      --Randy

 Edit: Marcus has some pictures of the KA1 and KA2 modules witht he shrink wrap removed, they are 6 and 5 supercaps all in series, 2.5V ones i the KA1 and 2.7V ones in the KA2.

[richg1998]

Couple letters in the URL where not there. Randy had an active link I did not see. Marcus always has a lot of good DCC info.

 

Rich

[larak]

Oops, "link not found" Rich. Maybe it's temporary.

[larak]

Thanks Randy and good advice for any lurkers, (I've been an EE for ... well a few decades now.) Just wondering at the capacitance value. The super caps name kind of gives that away. :-)

[larak]

The conversions for the F units were simple and flawless. The Switchers needed a more tender (no pun intended) touch since there is so little spare space inside. After a false start I found a way to isolate the frame from the lower motor brush holder. Clipping most of the solder lug and a machining (dremel) a tiny groove into the (purple) plastic to allow a 30ga wire to pass to the top did the trick. At first test, the lights did not come on. (The decoder's default condition for DCC is apparently off rather than on). I placed them back on a DC track and the lights worked - for two seconds - very bright before burning out. They need resistors for the conversion. DOH! I replaced them with LEDs and 330 ohm 1/4 watt resistors, pressed the "Lights" button on the DCC controller and all was well. I like the TCS decoders and recommend them. Thanks for the heads up. I will next tackle some full conversions on my older non DCC ready Moguls.

[rrinker]

 Don;t replace the bulbs, use golden white LEDs with a 1K resistor for each one. Never burn out again.

            --Randy