The RX Meter Type 250-A is a wide frequency range Impedance Meter designed to permit accurate individual determination of the equivalent parallel resistance and parallel reactance of two- terminal networks and components. The instrument is completely self-contained and consists,* fundamentally, of a refined Schering bridge circuit, together with its associated oscillator, detector, amplifier, null detector and power supply. Bridge balance is obtained by means of two calibrated dials which indicate, respectively, parallel resistance and parallel capacitance of the unknown. B. SPECIFICATIONS 1. FREQUENCY RANGE: 0. 5 me to 250 me. 2. RESISTANCE MEASUREMENTS: a. Range: 15 ohms to 100,000 ohms. (Values from 0 to 1512 maybe measured indirectly.) b. Accuracy: / ^ Rp Q ± 12 + ---- + ------ + — j % ± 0. 2 ohms v 200 5000 20/ where f = frequency in megacycles R„ - equivalent parallel resistance in. ohms indicated by RX Meter Rp Q ------- Xp as determined from RX Meter readings. 3. CAPACITANCE MEASUREMENTS: a. Range: 0 to 20 mmf. (May be extended to 120 mmf by use of auxiliary resonating coils.) b. Accuracy:±(0.5 ^ 0.5F2 *C*x 10-5)% ±-0.15/ifrf *F = frequency (MC); C = RX Meter Cp reading (^f) where f - frequency in megacycles. 4. INDUCTANCE MEASUREMENTS: a. Range: Inductance values which will resonate with capacitance from 0.1 mmf to 100 mmf over the frequency range of the instrument. By the use of auxiliary series resistors or capacitors, values of inductance maybe measured over the following ranges. Freq. Minimum Maximum 0.5 me 0* Ol^h 100 mh 250 me O.OOljuh 0.4 mh 5. VOLTAGE AT TEST TERMINALS: DC voltage = 0. (DC up to 50 ma. may be passed thru the terminals from external source.) RF voltage = approximately 0.1 to 0.5 volts. 6. POWER REQUIREMENTS: Voltage, 105-125 volts? frequency, 50-60 cps, power consumption,60 watts. (Voltage internally regulated.)