Philco TB-2 User manual

INSTRUCTIONS FOR
PHILCO TELEVISION BOOSTER
MODEL TB - 2
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The Philco Television Booster, Model TB-2, is a specially
designed amplifier for "boosting" television signals in cases
where, because of shielding effects or distance from the
station, television reception is un-satisfactory. It employs
two miniature-type tubes, and covers all twelve television
channels. To provide maximum efficiency over the entire
television band, separate amplifiers are incorporated for the
high-frequency and low-frequency portions of the band, and,
in addition, the unit is provided with two sets of input and
output connections, to permit the use of separate aerials on
the high-frequency and low-frequency channels. Adapt-
ability to all types of installations is provided by a design
which permits the use of twin-lead, shielded twin-lead, or
coaxial cable for the aerial leadin. Power for the operation of
the Booster (6.3 volts, a.c., and 250 volts, d.c.) is obtained
from the television receiver with which it is used, thereby
eliminating the necessity for an extra power supply, and
adding considerably to the compactness of the unit. An
additional advantage is that the unit is automatically turned
on and off with the television receiver.
INSTALLATION
In order to obtain the full performance of which the
Booster is capable, it is strongly recommended that the
installation be made by a qualified Philco Television
Serviceman.
INSTALLING ADAPTER CABLE
When attaching the Booster to the television set, First
locate the audio-output tube. This will ordinarily be a 6K6,
6V6, etc, when an octal type is used, or a 7B5, 7C5, etc.
when a Loktal tube is used. Refer to the accompanying
chart, which lists the audio-output tubes used in the principal
makes of receivers. To locate the proper tube in other sets,
tune in a television station in the usual manner, and then
remove any of the above, or similar type tubes, one at a time
(replace each tube before removing the next one), until the
tube is found which cuts off the sound.
After the audio-output tube has been located, the next step
is to install the adapter cable. The Booster is
NOTE: The Booster cannot be used with
television receivers of the AC-DC (series-
connected filaments) type.
supplied with either of two types of cable, one type (Part No.
41-3914) for receivers using a 6K6, 6V6, or similar octal
tube, the other type (Part No. 41-3913) for sets using 7B5,
7C5, or similar Loktal tube. Plug the adapter end of the cable
into the socket from which the tube has been removed, then
plug the tube into the adapter.
Next, refer to the accompanying chart, to see whether the
reversing plug should be used. This plug, furnished with the
Booster, is required with some receivers, to reverse the
filament and ground connections to the Booster. If the
information is not listed in the chart, proceed as follows:
1. With no other connections between the set and the
Booster, insert the small plug, on the end of the adapter
cable, into the receptacle on the Booster, and turn the set on.
2. Using an a-c voltmeter, set for about 10 volts full scale,
check between the Booster chassis and the television
chassis; if a reading is obtained (about 6.3 volts), the
reversing plug is necessary.
When the reversing plug is required, it should be plugged
onto the end of the adapter cable; the assembly should then
be inserted into the Booster receptacle.
Copyright, 1949, Philco Corporation

below. In some instances, considerable improvement is
obtained by varying the length of the leads between the
Booster and the television set. However, these leads should
never exceed 30 inches in length.
AERIAL CONNECTIONS
The Booster is primarily designed for two-aerial
operation. Connections for using two aerials with different
types of aerial transmission lines are shown

In cases where a single aerial is used, one of the following
connections should be made.
When the Booster is to be used with television receivers
having only a single input, the output connections from the
Booster to the receiver should be made as shown below.
Where only the low band is to be used, make connections
as shown in 1, 2, or 3, and remove the high-band amplifier
tube.
Wherever twin-lead is used, whether at the input or
output of the Booster, try reversing the connections of
each pair of leads, to determine the proper
connections for the best results on weak stations.
INSTALLING RESISTORS
Some receivers may require the installation of 220-ohm
resistors between the aerial connections on the set and the set
chassis, to prevent oscillation; this condition will be indicated
by a blurry, streaked picture-tube screen when the Booster is
tuned to the same channel as the television receiver. Resistors
may be necessary on either or both the high- or low-channel
aerial connections on the television receiver.
MOUNTING
The Booster may be mounted wherever convenient, using
the brackets furnished, the location being limited only by the
length of connecting leads found to give best results.
OPERATION
To operate the Booster, set the Booster control to the number
of the channel it is desired to receive, and tune in the
television station on the receiver in the regular manner. Then
carefully readjust the Booster control for the best picture.
SERVICE AND PARTS DIVISION
PHILCO CORPORATION
PHILADELPHIA, PA.
Part No. 39-9341 Printed in U. S. A.