With built in dual stabilized continously variable power supply, workable on 230 Volts AC, fitted with PNP transistor AC 128 on front panel, different terminals of transistor and meter connection are brought out on the panel with separate terminal, fitted with four MO 54 moving coil mters of 3V, 250uA, 50mA, 10V.
With built in stabilized power supply, workable on 220 volt AC, fitted with FET FW 10, power supply and three MO 65 moving coil meters, 3V, 15 mA, 15V.
With built - in power supply and two MO65 moving coil meters, workable on 230 volts AC fitted with diode valve on front panel. Consistof Hight voltage : 0-250 volts AC at 25 mA continously variable Low voltage : 6.3 volts AC at 2 amps with built in rheostat for filament current control.
With built - in power supply and two MO65 moving coil meters, workable on 230 volts AC fitted with triode valve on front panel. Consist of Hight voltage : 0-300 volts AC at 30 mA continously variable Bias : 0-15 volts DC at 5mA continously variable.Low voltage : 6.3 volts AC at 2 amps with built in rheostat for filament current control.
Wit built in stabilized power supply, workable on 230 Volts AC, thermister fitted with built in oven and thermometer is mounted on front panel, a heat control switc, on mili ammeter 10mA, on voltmeter 10V and separate terminal for thermister are provided.
PN Junction Diode App.) with built in dual power supply, workable on 230 volts AC, fitted wtih semi conductor diode and meter connection are brought out on panel with separate terminals, Four MO 65 moving coil meters 90 V, 100uA, 3V and 15 mA are provided. Output Bias : 0-1 volts DC continously variable (for forward bios) Input Bias : 0-30 volts DC continously variable (revese bias)
Same as 657 but with 2 dual range MO65 moving coil meters
