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Digitrax F40PH Sound Decoder

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  • Member since
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  • From: Oklahoma
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Digitrax F40PH Sound Decoder
Posted by Acela026 on Monday, May 16, 2011 9:39 PM

 

I have an older (~2005) Spectrum F40PH. It runs great, and when I make the jump to DCC (end of June is what I am hoping for) it is the first loco I would like to convert. I would like sound, but I don't need it if it will push me over my  $100 per-decoder budget. I saw Digitrax's SDH164K1C HO Scale Mobile Decoder (http://www.digitrax.com/prd_mobdec_sdh164k1c.php) specifically made for Kato F40PH's. Would it work in my loco? 

Acela

 

 The timbers beneath the rails are not the only ties that bind on the railroad.
           -
-Robert S. McGonigal

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Posted by simon1966 on Tuesday, May 17, 2011 7:40 AM

Since we discussed this loco before, have you taken the shell off and looked inside?  If, as I suspect, this is a heavy split frame Spectrum loco then you will have a hard time fitting a decoder, let alone a speaker for sound.  If you want to add a speaker it may well entail milling the frame to find the space for the speaker.  Anyway, make sure there is a place for it to go before going too far down this route. 

Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum

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Posted by richg1998 on Tuesday, May 17, 2011 8:29 AM

Acela026

 

I have an older (~2005) Spectrum F40PH. It runs great, and when I make the jump to DCC (end of June is what I am hoping for) it is the first loco I would like to convert. I would like sound, but I don't need it if it will push me over my  $100 per-decoder budget. I saw Digitrax's SDH164K1C HO Scale Mobile Decoder (http://www.digitrax.com/prd_mobdec_sdh164k1c.php) specifically made for Kato F40PH's. Would it work in my loco? 

Acela

 

I think the below link is your loco. A F40PH. The Bachmann site diagram says older F40PH.

http://www.bachmanntrains.com/home-usa/dwg/dwgs/H870X-IS005.pdf

You say it runs good so maybe it could be converted to DCC. I would first measure the motor current at 12 volts DC. I do that test with drivers slipping. Some take the shell off and hold the flywheel or drive coupling for locked rotor current test. Hopefully, the current is under 1 amp.

Then isolate the motor contacts from the frame halves. Solder the appropriate wires to the motor contacts.

No idea on what is used for track pickups though.

A Tsunami lightboard decoder would go in place of the factory equipped PC board. About $80.00 each. Few dollars more for the speaker.

The speaker, maybe up inside the shell. No idea how much room inside the shell with the frame in place.

I have put a 16mm x 35mm speaker in a homemade styrene baffle up inside a Spectrum 44 ton and Spectrum 70 ton and those shells are only 16mm wide. The speakers firedown when mounted inside the shells.

Rich

 

 

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

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Posted by riogrande5761 on Tuesday, May 17, 2011 9:20 AM

davidmbedard
Remember that DCC doesnt make your loco run any better, but more finiky.

David B

Joe Fugate of Coos Bay SP layout articles has recommended decoders with the back EMF which he claims smooths out the running of Athearn RTR loco's at slow speeds.  He even had a demo video on his website demonstrating this. 

 I've also read that if using that feature, have it fade out above the slow starting speeds if you are muing the loco with others so it doesn't buck or fight the loco's it is MU'd with.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by rrinker on Tuesday, May 17, 2011 9:50 AM

 It definitely helps, but it cant work miracles. If the mechanism binds, BEMF might keep it moving at a slower speed than without, but there will still eb jerkiness to the motion as the BEMF adds and removes power in an attempt to eep the motor moving at a constant rate. Where this shows up often is on grades, where an otherwise fine runnign loco with lots of slop in the drive train binds coming down hill as th eloco runs away and shifts the driveline one way, causing a bind, so the BEMF accelerates the motor to keep it moving, then overshoots and backs off and the loco gets ahead of the motor again and binds, over and over again.

 BEMF is particularly useful on steam locos - even if you have the drive and valve gear so perfectly set up that it rolls on a piece of glass, the forces ont he rods and piston vary as the drivers rotte, and BEMF in this situation will allow a slower consistent speed. Plus soudn decoders can use the BEMF to change the sounds for more labored chuffing when under load or bback off when drifting.

                   --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
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Posted by richg1998 on Tuesday, May 17, 2011 10:53 AM

Acela026

 

I have an older (~2005) Spectrum F40PH. It runs great, and when I make the jump to DCC (end of June is what I am hoping for) it is the first loco I would like to convert. I would like sound, but I don't need it if it will push me over my  $100 per-decoder budget. I saw Digitrax's SDH164K1C HO Scale Mobile Decoder (http://www.digitrax.com/prd_mobdec_sdh164k1c.php) specifically made for Kato F40PH's. Would it work in my loco? 

Acela

 

You can get some quite small non-sound decoders. Digitrax has the DZ125 good for 1 amp and two lights. $19.95 each. I have used them. About the diameter of a dime.

Digitrax has some with more light functions if needed.

I took time to look at your link and that might work.

Here the link is clickable.

http://www.digitrax.com/prd_mobdec_sdh164k1c.php

Take the shell off and do some measuring. That is what I do with any possible DCC or DCC sound installs.

The decoder companies usually have a size of the decoders at their site.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
    June 2007
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Posted by riogrande5761 on Tuesday, May 17, 2011 11:10 AM

rrinker

 It definitely helps, but it cant work miracles. If the mechanism binds, BEMF might keep it moving at a slower speed than without, but there will still eb jerkiness to the motion as the BEMF adds and removes power in an attempt to eep the motor moving at a constant rate. Where this shows up often is on grades, where an otherwise fine runnign loco with lots of slop in the drive train binds coming down hill as th eloco runs away and shifts the driveline one way, causing a bind, so the BEMF accelerates the motor to keep it moving, then overshoots and backs off and the loco gets ahead of the motor again and binds, over and over again.

                    --Randy

Yes, not a miracle cure but it can help significantly in area's where HO loco's tend to suffer the most, which is very slow speed operation. 

I haven't had a chance to test out operations yet since no layout, but the feed back us you want to program BEMF decoders to fade out the BEMF effect above slow speed operations so you won't get that effect you mentioned, whether on a grade or fighting loco's the BEMF is mu'd with.

Rio Grande.  The Action Road  - Focus 1977-1983

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  • From: Metro East St. Louis
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Posted by simon1966 on Tuesday, May 17, 2011 11:48 AM

As I mentioned in the OP's first thread asking about this loco, it is a decent candidate for a decoder.   The locos pull well, have a lot of weight from the die-cast frame.  When you get the light board out of the top of the shell there is sufficient space for a decoder.  I installed an inexpensive NCE fleet decoder D13SR, you have to be careful with insulation but the 4 light functions are good so you can add the flashers on the roof.   The biggest problem with these split frames is isolating the motor and improving the electrical path by eliminating the frame from the electrical pathway.   The link in the original post reply explains exactly how to do that using wires soldered to the pickups and cutting off the contacts that touch the frame.  Once done, these run fine.  The motor is not a power hog so no worries on the amp draw.

If you want picture of this locos specific installation i can take some for you, but the installtion I did on the TCS site is exactly the same concept.  http://www.tcsdcc.com/public_html/Customer_Content/Installation_Pictures/HO_Scale/Bachmann/Spectrum_Dash_8-40CW/Spectrum%20Dash%208-40CW.html

However, getting a speaker in here is going to be very hard.  There is no room in the fuel tank, the frame fills it.  There is little room above the split frame.   This would require so serious milling to make space for a decent size speaker.

Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum

  • Member since
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  • From: Oklahoma
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Posted by Acela026 on Tuesday, May 17, 2011 5:54 PM

I looked, probably enough room for a small decoder, but not enough for a speaker.  I don't want to mess with milling, either.  Thanks for the help, guys!

Acela

 The timbers beneath the rails are not the only ties that bind on the railroad.
           -
-Robert S. McGonigal

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