I recently purchased a P&D Hobby repower kit for a Red Caboose GP9 and had a few questions for any members of the group that has experience with these kits.

First I plan on installing a Soundtrax Tsunami 2 decoder. Will a 2200 (2 amp) decoder work for this application? 

Second what is the best way to paint the trucks? It looks like they can be disassembled to be painted but worried that the journals and associated springs will go flying if it is dissembled.




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I recently installed a TSU-2200 in an older CLW GP9 that had an open frame motor. The 2 amp decoder was not sufficient enough for the current draw and replaced it with the 4 amp version. Assuming you have a more modern can motor, it will draw less. Run a current draw test to determine decoder rating.

The good news is the Tsunami2 will shut down if it is overdrawn. Preserving it.

I think the pittman motor will draw a little more than 2 amps under heavy load.    I have some weaver RS3  models that use a similar or the same motor, and they will draw a little more under load.    So the best idea is to test the current draw under load and see what it is.  

As for the trucks, I have a pair of P&D F3s that might have the same brass trucks which I assume are what you are referring to.    I did not disassemble mine for painting that I remember.     I would be really cautious because of the complexity and springs.

The TSU2200 is rated for 2 amps STALL current.  Pittman 8000 series can motors come in a wide variety of windings but my recollection is that they all draw quite a bit more than 2 amps when the motor is stalled (current measured when full rated voltage is on the motor and the shaft is held so that it won't turn).  .  Note that the stall current draw of the motors we use is quite a bit higher than what we measure when our locomotives are running under load on the railroad.  The Tsunami's have internal firmware that will automatically shut the decoder down if the installation exceeds the design limit of the decoder.  When a Tsunami is about to shut itself down due to excess current draw the headlight on the model will flash on and off 12 times.  After a pause it will reset and shut down again if the limit still is exceeded.  This is a design feature to prevent decoder burnout and related warrantee returns.   

According to a Pittman document in my possession the 12 Volt 8414 motor supplied in the P&D GP9 re-power kit has a rated stall current of 7.9 Amperes. Unless you have a flat switching layout, with very few cars per train, like Ed I really wouldn't recommend a 2A stall rated decoder.

There are a few additional  things you may want to know.

The fabulously-detailed equalized P&D brass trucks have electrical pick up on only one side, through the axle bearings and multiple moving surface interfaces. On my F3s I found that to result in less-than-satisfactory electrical pickup. I installed wipers to the back side of all 4 wheels using the gearbox screws to mount them (4 wipers per truck.)

Doing so requires removing at least one side frame from the truck. While disassembled I mask off the bearing and threaded holes to keep paint out of sensitive areas, and clean/re-lube the gearbox. Reassembly is really not at all difficult if one's fingers still have fine motor control (I'm thankful I still do.) 

The most elegant all-wheel pickup installs I've seen posted to the web were done by Jay Criswell. Everything he does is top-rate. Two thumbs up, Jay!

Also be on the lookout for a cracked axle gear or motor universal attachment (P&D calls the latter "helmets.") Cracking has happened on Delrin gears and drive parts throughout the model train industry when an acetyl part shrinks over time. "Hoop stress" causes the part to crack around an axle or motor shaft.

Please don't get me wrong. I'm not desiring to be in any way be negative. I really like the P&D kits.

I have 5 P&D GP7 re-power kits that I bought years ago and 7 more F unit kits to build, the first first one purchased ~19 years ago. Over the interveining years, stuff happens (wish I was 19 years younger but knowing what I do now!) Despite an occasional issue, I really like them. In my case, with Loksound V4L decoders and 2" high-bass speakers in my F3s, they sound awesome.

I'm just starting to work on my GP9s. They will receive Tang Band 4 ohm T1-1931S modules firing down, mounted through the fuel and air tanks, driven by Loksound 5LDCC decoders. The remaining F3s will get Tang Band T1-1828S speakers after milling holes in the frame for the passive radiator to fire down at the track, sound coming out of the dynamic brake air intakes and exhaust grills.

Here is a link to short video I shot on an iPhone with external stereo microphone (scene 2 to end) of an Overland brass Alco C425 with TB 1925 speaker and a Loksound V4L decoder. The last shot is an ABA set of P&D F3s grinding upgrade with V4L decoders and 2" high-bass speakers. Turn the sound up.



The primary problem is that the sound generators are Loksound DCC decoders. That's DCC, not 3R AC. The Alco speaker is just a 4 ohm Tang Band module. I know that a larger TB module has been fitted into the tender of a 3R Hudson steam engine and it sounded awesome in the shared videos.

In summary, there are three pieces to the puzzle: A decoder with great sound quality, a speaker up to the task to play the sounds, especially the bass, and a compatible control system.

All the best!

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