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Notes on Early Philco Chairsides: Information on the Connecting Cable & Speaker Box used with Models 14LZX, 19LZX, 19TX & 91RX These Philco Models, all made in 1933, use an eight-conductor, 25-foot cable from the radio chassis to the separate speaker. The cable contains not only the speaker field coil and output transformer leads, but also antenna, ground, and the AC line. Although these sets are all on the rare side, you may have occasion to acquire and restore one. Therefore we present the following brief information, not found in Rider's Manuals or any other service literature that we are aware of: the pinouts for the cable itself, plus a schematic of the speaker box which is attached to the back of the separate speaker cabinet, and which the 25-foot control cord plugs into. First, let's take a look at the cable. It is flat, cloth-covered, and (unfortunately) the eight conductors inside the cloth outer covering all have black rubber insulation (not colour-coded). Here is a pinout of the 14LZX and 91RX cable:
And now a pinout of the 19LZX and 19TX cable:
These are views of the plug end of the cable, which shows how each wire connects
inside the radio chassis.
Now let us turn our attention to the speaker box. This is a small metal box which,
as mentioned above, is mounted in back of the separate speaker cabinet. The box
has two sockets - one special 8-contact socket for the speaker cable plug, and a
3-contact socket for an external speaker (only two of the three contacts are
used).
A schematic diagram of the 14LZX and 91RX speaker box is shown below.
And this is a schematic diagram of the 19LZX and 19TX speaker box:
The AC cord comes out of this box, and the box also has the antenna and ground
Fahnestock clips mounted on it, between the two sockets. In addition, four wires
(three on the 19LZX & 19TX) run from inside this box to the speaker mounted
inside the speaker cabinet.
Note the external speaker connection on the right side of the box as shown above. Do
not connect a speaker direct to that socket - it has B+ on both terminals! It is
designed for the primary of an output transformer to be connected to those two
terminals; the external speaker's voice coil would then be connected to the
secondary of the external audio output transformer. Return to the Tech Section Index. © 1997-2006, Ron Ramirez. All
rights reserved. Unauthorized duplication prohibited.
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