Dale PH-25 Reference manual

Introduction
Congratulations on purchasing the Resistor Volume Knob that allows you to adjust the volume
on your Spirit Proton Pack by rotating a replica Dale PH-25 power resistor mounted on the side
of the Ion Arm.
A Spirit Halloween Deluxe Proton Pack (not included) shown with the Resistor Volume Knob
installed:
Here is a reference photo of a screen used pack:

Installation in the Spirit Halloween Pack
Parts Identification:
There are only two parts, the replica resistor knob and the mounting spacer:
Shown here with a real Dale PH25 resistor and the volume pot from the Matty Blaster or the
Spirit Blaster Sound Board kits along with the two parts from this kit:

Pack Knob prep:
The Knob is 3D printed and has “support structures”to enable the internal structures to be placed
at the correct locations. I first use pliers and then a small straight screwdriver to pull and scrape
the support structures out of the inside of the knob. This can leave a lumpy surface, but it is not
visible once the knob is mounted.
On the left is the part as you will receive it and the part on the right has the support structures
removed:

Spirit Pack Volume Potentiometer Install:
Only a couple of things needed to get the volume control installed:
1) Remove the back cover of the pack –you do need access to the inside of the pack for this
installation.
2) Remove the original knob
Cut off this knob. It really isn’t a very good replica of the ideal Dale resistor anyway.
You do not need to get too close to the surface since the knob is not molded into the shell,
just heat staked/glued by a central shaft.
After the knob is cutoff about a 1/4”above the surface:

3) Next remove the leftover post.
I used a 3/16”drill to get that out and then a 1/4”to make the hole. The 1/4”hole is too
snug so either ream that out, or just use a larger bit. I used a 5/16”bit and that worked
well but made a larger hole than needed. I suspect a 9/32”would be ideal, but I do not
have one of those bits!
4) Mount/glue the spacer.
The space sits on the potentiometer so that it sits at the correct depth once mounted in the
pack.

Do a test fit and mount before gluing. Then glue the surface of the spacer that comes in
contact with the shell and mount in the pack. You do not _need_ to glue it, but gluing
will help hold the volume knob in the correct orientation and not accidentally allow the
potentiometer to rotate when you try and turn the knob too far.
Once mounted the knob should look like this from the outside:
On the inside:

5) Next, just press the knob onto the knurled shaft of the potentiometer.
This does take some effort but making it easier would risk having the knob fall off.
Now put the pack’s back cover on and you are done!