Installing a sound decoder - 5
engine, and vice-versa; if not, you must enlarge the holes until
you can get that amount of movement. Remove the cable for
now, touch up the paint around the openings, and set it aside.
Tender speaker
In 98% of rectangular tenders, you can mount the speaker on
the floor, and many engines have the holes already drilled for
you. If not, you will need to drill holes in it for the sound to go
out. If there is absolutely no way to mount the speaker on the
floor, I have mounted speakers in the coal pile and drilled 40 or
50 holes in the coal for the sound to come out the top, and it
sounded good.
The tender itself makes a great enclosure, and you will be
amazed at how loud it will be if the speaker is mounted so it is
sealed around the opening or holes.
Try and use the largest speaker you have room for, but be sure
it has 8 ohms impedance. Test it first with a 1.5V battery with a
1.2K resistor in series to make sure it makes some static when
you touch the terminals with it.
In a Vanderbilt tender, you may have to build a small baffle of
plastic or cardboard to seal off the ends of the speaker from the
curved tank bottom. Find a location on the frame where you can
drill enough holes for it and not hit any brake parts, then scribe
a circle around it in pencil and drill the holes about 1/8” apart. A
3/16” or 5/32” bit works well, but be sure to anchor the tender
securely when drilling!
After smoothing off the holes, paint them and then you can
mount the speaker. I use any good silicone RTV, since it holds
well, but the speaker can be removed fairly easy if it ever
needs replacement.
MRH-Dec 2013
