VOLUME CONTROL AT MAXIMUM
Socket No.
Filament Volts
Filament to Control
Grid Volts
Filament to Screen
Grid Volts
Filament to
Plate
—Volts
Plate Current
Milliamperes
1
3.2
1.6
67
135
5.0
2
3.2
1.6
67
135
3.0
3
5.0
------
——
45
3.5
4
5.0
9
-------
125
6.5
5
5.0
27
——
130
15
Figure 6
—Schematic circuit diagram of Radiolas
21
and
22
receivers
(3) RADIOLA 21 OR 22 CONTINUITY TESTS 1060
The following tests will show complete continuity for the receiver assembly of Radiolas 21 and 22.
Disconnect the antenna and ground leads, the cable connections to all batteries, and unscrew the pilot lamp.
A pair of headphones with at least 4^2 volts in series or a voltmeter with sufficient battery to give a good
deflection when connected across the battery terminals should
be
used in making these tests.
The resistance of the various circuits are also shown in the column titled, "Correct Effect." Checking the
resistance of the circuits adds an additional check on their correct functioning. This may be done by means of a direct
reading "Ohmmeter," a resistance bridge, or any of the methods shown in previous issues of RCA Service Notes.
The Radiotron contacts and socket numbers, the cable connections and color scheme
are
shown in Figures 7
and 8, and should be referred to when making these tests. Figure 5 illustrates the internal connections of the A.F.
coupling unit.
11
1059
