Sound P42

[John]

I want to pick up one of the Kato Veterans units and equip it with sound .. I've never done sound install .. what's your experience .. Milled frame?  Other?

[peteski]

If you want to install anything but the crappy Digitrax plug-n-play sound decoder with its tiny and enclosure-free decoder, some milling will be required to house the decoder/speaker/enclosure/capacitor.

[jdcolombo]

I don't have experience with the P42, but in general I'd recommend using an ESU LokSound Select Micro (there is a specific sound file available for the P42, file #73882), an 11x15mm flat cell-phone-type speaker in an enclosure that has at least 800 cubic mm of interior volume, and a minimum of 220uf of "keep alive" capacitance (more is better).  The ESU Loksound will probably fit in the center area of the P42 frame - it looks from photos I have seen that there is a sort of channel there, but if not, you'll need to mill one.  Then you will need to mill the frame for the speaker/enclosure.  Note that you can get to 800 cubic mm a variety of different ways - you could make an enclosure that is relatively "thin" but long, with the speaker mounted down at one end (if you've seen the speaker enclosure for a BLI PA-1, this is how they do it, and I mounted an 11x15 speaker in that with excellent results - you can see the thread here: https://www.therailwire.net/forum/index.php?topic=38621.0 ).  Or you can make a traditional rectangular box that is 5.5mm deep (11 x 15 x 5.5 = 907.5, which provides some cushion for the volume losses from the speaker itself).  From the photos I've seen of the P42 with the shell off, the rear of the chassis looks like the obvious place to mount the speaker; for a rear headlight, you can glue an SMT LED to the back of the speaker enclosure and run the wires underneath the enclosure between the frame halves.  For a dropping resistor, use a 1K, 1/8w (you can use a regular carbon dropping resistor for this, or if you are pressed for space, you can use a 1/8 surface-mount one if you have the tools/patience to solder the wires to it).  You can probably find a way to keep the front part of the standard PC board for the front LED and power pickup (or if you decide to mount the speaker in the front, use the rear part of the board for the rear LED and power pickup).

Possible Suppliers:
LokSound Select Micro: sbs4dcc.com (specify sound file 73882; Bryan will install it for you before shipping the decoder)
Speaker: Digikey - Soberton 11 x 15mm: http://www.digikey.com/product-detail/en/soberton-inc/SP-1511S-5/433-1129-ND/6099103
Keep alive caps: Digikey, tantalum 16v, 220uf: http://www.digikey.com/product-detail/en/avx-corporation/F931C227KNC/478-8257-1-ND/4005713
Surface-mount LED: sbs4dcc.com or Richmond Controls (both sell them with leads attached; Richmond Controls is a little cheaper)

Note that the 16v tantalum cap recommendation assumes that you keep your track voltage below 14v; if you don't, or are not sure, then use two 150uf, 20v caps: http://www.digikey.com/product-detail/en/kemet/T491X157K020AT/399-4794-1-ND/1085513

John C.

[John]

Thanks John .. I may have to rethink this some .. but it's great information

[peteski]

P42 chassis is similar to Kato E8.  Here is an example of a milled-out E8 frame.  That opening houses a speaker which is mounted on the bottom of the opening (and sends the sound down toward the rails).  The opening also houses a bank of tantalum caps. then I sealed the top of the opening with piece of styrene (lead woudl have been even better). So the speakers and the caps are sealed in that cavity.

This was an install of the Digitrax decoder I did for a friend,. I used the tiny speaker which came with it (that was all he wanted). The sealed enclosure improved the quality of the sound produced by the tiny speaker.

[John]

that would work .. I wonder if Aztec would mill the frames?

[peteski]

that would work .. I wonder if Aztec would mill the frames?

Actually now that you mentioned that, I think Aztec does mill those frames for sound.

[John]

Actually now that you mentioned that, I think Aztec does mill those frames for sound.

Got an email back from John --- thats not a frame the would do .. guess I will get out the drill and dremel

[peteski]

Got an email back from John --- thats not a frame the would do .. guess I will get out the drill and dremel

Oh well...  He does mill Kato E8s which as I mentioned is very similar to P42.  I guess it is different enough that he would have to make another milling fixture.

[woodone]

A round hole, 15 MM will also work with a 15 MM speaker. Just a blind hole- Don't drill or mill al the way through.
A Loksound Select will fit right on the old PC board.

[tehachapifan]

One other possibility, since this is a first sound install attempt and the P42 does not appear to have very much extra room, is to maybe consider doing the install in a leading baggage or MHC car instead.

[nscaler711]

I have a loksound select micro decoder in my Amtrak 66, so my only advise is use the original board and cut the contacts to the motor, and also use a resistor for the forward headlight, I have always used a 470ohm resistor and have never had any issues on DCC or DC. (This is just me, other resistors can be used, I just prefer that for the light intensity.)
I would definitely use a better speaker than what I currently use; a smart phone speaker out of a HTC One M8.
Also the Decoder will easily fit between the shell and the top of the board, just keep any wires short.
As for ditchlights, there are a lot of tutorials out there for those, most involve cutting the light tubes, and using SMD LEDs.