GENERAL RADIO COMPANY 1433 Instructions Manual

INSTRUCTIONS
Type 1433
DECADE
RESISTOR
SPECIFICATIONS
Accuracy: The specified tolerances apply for low-current meas-
urement at dc or low-frequency ac (see below).
Over-all Accuracy: The difference between the resistances at
any setting and at the zero setting is equal to the indicated
value +(0.01% + 2 m9).
Incremental Acturacy: See table. This is the accuracy of the
change in resistance between any two settings on the same
dial.
Max Current: The max current for each decade is given in the
table below and also appears on the panel of each decade box
and on the dial plate of each decade resistance unit.
Frequency Characteristic: The accompanying plot shows the
max percentage change in effective series resistance, as a
function of frequency for the individual decade units. For low-
resistance decades the error is due almost entirely to skin
effect and is independent of switch setting. For the high-
resistance units the error is due almost entirely to the shunt
capacitance and its losses and is approx proportional to the
square of the resistance setting.
The high-resistance decades (510-E, -F, -G, and -H) are very
commonly used as parallel resistance elements in resonant
circuits, in which the shunt capacitance of the decades be-
comes part of the tuning capacitance. The parallel resistance
changes by only a fraction (between a tenth and a hundredth)
of the series-resistance change, depending on frequency and
the insulating material in the switch.
Characteristics of the 1433's are similar to those of the indi-
1433-U A BA,A,B,C - 1433-9700 1433-9701
1433-K 11 A ABOD 1433-9702 1433-9703
1433-J Alt 4 B. OD E 1433-9704 1433-9705 aR
1433-L 111100. 6 4 C, D E, F 1433-9706 1433-9707
1433-Q 1,111,000 0O- 4 D,E,F,G 1433-9708 1433-9709 c
1433-T ALL 0.01 5 AA, A, B,C, D 1433-9710 1433-9711
1433-N 11111. 0.1 5 A; B,C, DO, E 1433-9712 1433-9713 Ro Lo
1433-M 111,110 1 5 B,C,D,E,F 1433-9714 1433-9715
1433-P 1,111,100 20 5 €, D, EF, G 1433-9716 1433-9717
1433-Y 11,111,000 100 9 DE H 1433-9718 1433-9719
1433-W 11,111.1 0.01 6 AA, A , B, C, D , 1433-9720 1433-9721
1433-X 111,111 0.1 6 A, B, C, D, E, F 1433-9722 1433-9723
1433-B 1,111,110 1 6 B,CD EFG 1433-9724 1433-9725
1433-Z 11,111,100 10 6 CHEF GH 1433-9726 1433-9728 Equivalent circuit of a resistance
1433-F ROP Se bp Bs dd 0.01. 7 AA, A, B,C, D, E, F 1433-9729 1433-9730 decade, showing residual
1433-G reek Ad 0.4: 7: AB ODE F,G - 1433-9731 1433-9732 dances.
1433-H 11,111,110 1 7 B, C, D, E,F, GH 1433-9733 1433-9734
DECADE-RESISTANCE UNITS
Total Resistance Accuracy of Max Power
Resistance — Per Step Resistance Current Per Step: AL CE Lo
Type -Ohms _ (AR) Ohms Increments 40°CRise Watts uH pF uH
510-AA E 0.1 0.01 +2% 4 A 0.16 0.01 7:7-4.5 0.023
510-B „10 1 +0.1% 800 mA 0.6 0.056 7.7-4.5 0.023
510-C 100 10 +0.04% 250 mA 0.6 0.11 7.7-4.5 0.023
510-D 1000 100 +0.01% 80 mA 0.6 5 7.7-4.5 0.023
510-E 10,000 1000 +0.01% 23 mA 0.5 13 7.7-4.5 0.023
510-F 100,000 10,000 +0.01% 7 mA 0.5 70 7.7-4.5 0.023
510-G 1,000,000 100,000 +0.01% 2.3 mA 0.5 — 7.7-4.5 0.023
510-H 10,000,000 1,000,000 +0.01% 0.7* mA 0.5 — 7.5-4.5 0.023
* Or a max of 4000 V, pk.
DECADE RESISTOR
PN EET. WEN
1
General Radio ol
Figure 1-1. Type 1433-T Decade Resistor.
vidual 510's modified by the increased series inductance, Lo,
and shunt capacitance, C, due to the wiring and the presence
of more than one decade in the assembly. At total resistance
settings of approx 1000 ohms or less, the frequency charac-
teristics of any of these decade resistors are substantially the
same as those shown for the 510's. At higher settings, shunt
capacitance becomes the controlling factor, and the effective
value of this capacitance depends upon the settings of the
individual decades.
Typical Values of R., L, and C for the Decade Resistors:
Zero Resistance (R.): 0.001 £ per dial at dc; 0.04 Q per dial
at 1 MHz; proportional to square root of frequency at all fre-
quencies above 100 kHz.
Zero Inductance (L): 0.1 ¿H per dial + 0.2 „H.
Effective Shunt Capacitance (C): This value is determined
largely by the highest decade in use. With the low terminal
connected to the shield, a value of 15 to 10 pF per decade may
be assumed, counting decades down from the highest. Thus,
if the third decade from the top is the highest resistance
decade in circuit (i.e., not set at zero), the shunting terminal
capacitance is 45 to 30 pF. If the highest decade in the as-
sembly is in use, the effective capacitance is 15 to 10 pF, re-
gardless of the settings of the lower-resistance decades.
Temperature Coefficient of Resistance: Less than +10 ppm
per degree C for values above 100 2 and =20 ppm per degree
C for 100 Q and below, at room temperatures. For the 1433's
tne box wiring will increase the over-all temperature coefficient
of the 0.1- and 0.01-2 decades.
No. of
Switches: Quadruple-leaf brushes bear on lubricated contact
studs of %-in. diameter in such a manner as to avoid cutting
but yet give a good wiping action. A ball-on-cam detent is
provided. There are eleven contact points (O to 10 inclusive).
The switch resistance is less than 0.0005 2. The effective
capacitance is of the order of 5 pF, with a dissipation factor of
0.06 at 1 kHz for the standard cellulose-filled molded phenolic
switch form and 0.01 for the mica-filled phenolic form used in
the 510-G and 510-H units.
Max Voltage to Case: 2000 V pk.
Terminals: Low-thermal-emf jack-top binding posts on stan-
dard %-in. spacing; also\provisions for rear-panel connections.
Shield terminal is provider,
Mounting: Lab-bench cabinet, rack models include mounting
hardware.
Dimensions and Weights: in. (mm), |b (kg):
4-dial 5-dial 6-dial 7-dial
UKJLQ T,N,M,P,Y WBZ F,G,H
Width* 12.3 (312) 14.8 (375) 17.3 (439)
Height 3.5 (89) | 5-3 (135)
Depth 5 in. over-all, 4 in. behind panel (127, 102)
Net Wt** 4.8 (2.2) | 5.8 (2.7) 4 7 (3.2) | 8.8 (4.0)
Ship. Wt** 5.5 (2.5) 6.5 (3.0) 8.5 (3.9) 10.3 (4.7)
* Data given for bench models. All rack models same except 19 in.
(483 mm) wide.
** Add approx 1 Ib (0.5 kg) for rack-mount hardware
Catalog Number
Rack