Tektronix Type 130, Instruction Manual

Page: 27 / 53

S-30 Delta Standard — Type 130
AA
6-3
Fig. 6.2. The Type S-30 and the Type 130 L-C Meter connected with
the Inductance Standardizer. .
inductance will not be the same at 1 kc or 1.59 kc. In
addition, shunt capacitance across L15, representing about
1/3 or 1% of L15’s admittance at 140 kc, will not have the
same effect at typical bridge frequencies.
To calibrate the 300
μ
h range of the Type 130 construc-
tion of the Inductance Standardizer shown in Fig. 6-2 and
in the circuit on page 6-2 is suggested. The value of the
capacitor and resistor must be within 2% of those shown.
Connect the Type S-30, the Inductance Standardizer, and
the Type 130 as shown in Fig. 6-2. Place the switch of the
Type 130 in the 300
μ
h position. Depress the switch on the
Inductance Standardizer. With the COARSE and FINE ZERO
controls bring the meter reading of the Type 130 to 0.
With the switch depressed, the 100-400
μ
h coil is
parallel resonant with the internal capacity of the 130 LC
Meter, and the 7.5 Ω resistor replaces the DC resistance of
the 300
μ
h coil in the S-30.
Release the shorting switch on the Inductance Standard-
izer and adjust L15 in the S-30 until the Type 130 Meter
reading is brought back to 0.
The 4310
μμ
F capacitor in the Inductance Standardizer
is series resonant with the 300
μ
h coil in the S-30 at 140 kc,
and the 130 sees only the 7.5 Ω resistance of the coil.
Replace the outer case of the Type S-30.