Table Of Contents; To Ground; De Volts - GENERAL RADIO COMPANY 1263-8 Operating Instructions Manual

GENERAL RADIO COMPANY
g. Vary the line voltage from 105 to 125 (or 210 to 250) volts.
h. The total shift in meter indication should be less than one scale
division.
Completely satisfactory performance can be obtained with tubes
showing drifts greater than defined above if the line-voltage variations
are not extreme.
6.3 CALIBRATION.
In addition to the normal operating adjustments described in the
preceding sections, there are two internal controls. One of these
is
a
factory-set, sealed control (R14, accessible from the bottom of the in-
strument) and will not require adjustment except with failure and replace-
ment of RX1, Rl3, R14, R15, R27, or R75. After replacement of any of
these, set the panel selector switch to the CHECK
position
and adjust
R14 so that the ac potential at the OUTPUT RECTIFIER connector
is
the same as that indicated on the panel voltmeter. An accurate vacuum-
tube voltmeter should be used.
The other internal control
is
R2, accessible from the top of the in-
strument. No adjustment of this control
is
necessary since
it is
set at
its
counterclockwise
limit
and
is
provided only for making the test de-
scribed in paragraph 6.2.
6.4 TABLE OF VOLTAGES AND RESISTANCES.
Tube
Pin
De Volts Res. to
Tube
Pin
De Volts
Res. to
to Ground Ground
to Ground
Ground
V1 1 +188 v
520 k
V4 1
+65 v
220 k
(12AX7)
2
-.02 v 1.1k
(5963)
2 -43 v
780 k
3
+2.05 v
300 k 3
0
0
4, 5-9 6.7 v ae 4,5-9 6. 7 v ac
6 +200 v
320 k
6 +88 v
220 k
7 -.02 v
100 k 7 -50 v
780 k
8
+2.05 v 300 k 8
0
0
V2
1 +325 v
51 k
V5 1 +uov
430 k
(12AX7) 2 0
3.4 M
(12AX7) 2
-58 v
900 k
3 +3.0 v 160 k 3
0
0
4,5-9 6.7 v ac 4, 5-9 6.7 v ac
6 +325 v
51 k
6 +350 v
1 k
7
0
3.3 M
7
-59 v
!.25M
8 +3.0 v
160 k
8
0 200 k
V3 1 +350 v
1 k
V6 2-7
6.7 v ac
(12AX7)
2 +lOOv
1M
(6V6GT)
3 0
Open
3
+102 v 100 k
4 +180 v
6k
4, 5-9
6.7 v ac
5
-55 v
200 k
6 +130
430 k
8
0
0
7 +101v
920k V7
2, 7 -150 v 6.2 k
8 +102v
100 k (OA2)
18