


After considerable research, we chose Colorado Plastic Products of
Boulder, Colorado to make the replica. Their master fabricator John
Butler studied the photos and concluded that he could make the cabinet.
Dave Sica generously agreed to loan us his TRK-12 cabinet to use as a
model, and we had it shipped to Boulder.
The museum wants to be able to display pictures on the set. Since it
wouldn't be practical to operate a 1939 set several hours a day,
we decided to use a small LCD display instead. In order to hide the LCD
display, we will have a wooden replica of the 12AP4 CRT made, with the
display embedded in the top. One issue with the LCD is that the image
needs to be reversed on it to display normally through the mirror. This
will be done either with a custom Aurora standards converter, or with a
PC using custom software.
Here are photos of what has been made so far.
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Outer case
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The CRT shield
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Radio and TV top panels |

CRT cover |

The TV and radio chassis, ready to be installed

The cabinet (on its side), with the radio and TV top
panels installed. You can also see the cabinet back (on
top)

The radio chassis installed
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Side view of the radio
chassis |

John Butler, master plastic fabricator at Colorado
Plastic Products
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The LCD screen that will be inserted in the top of the wood 12AP4
replica



The completed plastic cabinet

The replica CRT shell, made of high density foam

Casey Balsley, our woodworking expert

The original high voltage lead to the CRT, which we are replacing with
one containing the VGA and power connections for the LCD screen

We started with a short piece of 10-3 electrical cable and removed all
the wires

Then we installed the VGA and power cables inside the sheath and put on
the plastic cover that mates with the side of the CRT, and the ceramic
insulator that goes in the television power supply chassis. The cables
had to be cut to do this, and 3 very small connectors will be installed
on the cables. These connectors are small enough to go through the 3/4
inch hole in the television power supply chassis and will allow the
other end of the VGA cable to be re-connected.

We cut the end off of a 12LP4 CRT and filed down the evacuation nipple

A yellow LED was installed in the base and through the evacuation nipple
to the electron gun to simulate the glow of a filament

Then the base was glued on. The neck assembly will be put inside the
deflection yoke, which will hide the joint between the neck and the CRT
shell. A LED will also be installed inside the high voltage rectifier
cage to simulate the glow of the rectifier tube. A power transformer
will be hidden under the TV power supply chassis for the LEDs and for
the filament of the 5U4 low voltage rectifier tube.
The project is ready to ship. These photos are with the lid removed.

The LCD screen is embedded in a white plastic cap over the replica CRT.



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The base, with power
supply chassis installed. Under the TV
power supply are two transformers - one
for the LED in the neck of the CRT, and
the other for the LCD screen. Also under
the chassis is the end of the VGA cable.
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The completed anode
connector. The two mini connectors are
for the VGA cable for the LCD screen.
The bare wires are the power for the LCD
screen. The plastic cover fits on to a
small piece of 1/2 inch pipe embedded in
the side of the replica CRT, and the
wires go inside the CRT and are
connected to the LCD screen. |