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June 16, 2006
Installing the SDH104K1 Combo (SDH104K1 + FN04K1)A
in an Athearn RTR Dash 9
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Submitted by Jim Oliver
Just wanted to add some observations/comments on the newly released
sound decoder from Digitrax. I was a bit cautious about this as it was more
specific for the Kato unit, however, I wanted to install it in my Athearn
RTR Dash 9.
After looking at the instructions, as well as a Kato demo unit, I felt
I could tackle this. The big problem would be the speaker, but I'd cross
that bridge later. First, I removed all the wires to the Athearn jumper
board with the DH123 decoder I'd previously installed. The one thing I
don't like about Athearn is the use of the frame for track power, so this
was now removed. The wires off the trucks were too short, so new ones were
solder in the old one's place. I then soldered new wires to the metal plate
on the truck for track power from the left side. This gave me four wires;
two per truck for right and left pickup. Next was to solder a wire to the
top of the motor (the Athearn jumper board acts as the negative contact). I
noted in the instructions, as well as the demo unit, that Kato has two small
tabs that 'plug in' to the bottom of the decoder. Rather than use a screw
as suggested, I gently applied a dab of solder into the hole, using a low
amp rechargeable solder tool. The solder is applied to the tip, then to the
hole. This prevents any heat build-up. Next, install the four track wires
under the small sprung clips. I then checked for orientation of the loco on
my test track. Success! It ran in the right direction.
Now, the fun part . . . . installing the speaker. This is a large
speaker compared to Soundtraxx ones I've used. I needed a place to mount
it, and found the space in the radiator wings to be the perfect place for
this. Some small modifications were made, like a new cross brace to hold
the speaker somewhat in place. I also added two narrow strips of plastic
along the insides of the rad cover. This was to snug the speaker in place
and prevent side to side movement. I could have used some clear silicon
caulk to mount it more permanently, and will do so later, once I buy a set
of the Miniatronics male/female plugs, so I can disconnect the speaker from
the decoder when performing maintenance. But for now, this works
perfectly. The speaker is aimed downward, so the sound is projected over
the gear tower and rear truck.
This worked fine, but on some sections of track, I noted a slight
reverberation on the rails. I took the foam paper Athearn uses in their
blue box locos, cut a small strip, pressed it inside the rad top, then
snapped it back in place. Perfect!! The sound is crisp and has the
fidelity I'd expect. The bell still sounds too electronic, but is OK. All
sounds were reset using LocoBuffer-II, which I use for all my programming.
The only CV I have had trouble with is CV155. I wanted to set the ramping
effect to manual, rather than letting the decoder decide this. As it is,
the sound starts up when the throttle is turned up and seems to stay at a
set rate. Very little ramping can be detected as speed is increased. I
tried different settings on the Notching setting, but nothing happened.
Still, I am reasonably impressed with this decoders' sound. I know the
AC4400 has a different prime mover than the Dash 9, but it's acceptable for
now. One thing I do wish is Digitrax providing a bit more explanation
about the various CV's and what they are/used for. Many mean nothing to me,
making setting some CV's more of a mystery than they should be.
I might also add that when I wrote Digitrax about some settings on the
Tower 55 AC4400, I got a reply that the decoder is "like" their DH163,
meaning it really isn't (and it really isn't!!). I was told later versions
would be easier to program, and that this is not two decoders, but rather
one, with the function piece added. Kind of cheesy, if you'd ask me.
Jim Oliver |
