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OPERATING INSTRUCTIONS FOR THE "UNIVERSITY" MODEL TVT VALVE TESTER AND THE TST/2 VALVE AND CIRCUIT TESTER. GENERAL This instrument has been developed to fulfil the requirement of a completely flexible method of testing modern radio and television valves. It incorporates lever switches for element selection, which enables it to test any future types of valves regardless of their base connections. A masking plate covers three spare socket holes in the front panel to enable additional sockets to be fitted should new types come into use. The principle of testing conforms to standard RMA practice CONTROLS "LINE" This control is situated in the bottom left hand corner of the front panel and its purpose is to compensate for varying line voltages. FILAMENT VOLTS "A" Filament volts are selected for the valve under test by two switches, which are situated next to the "LINE" switch on the bottom of the front panel. The filament voltages available are from 0.6 to 117, the first switch selecting up to 12.6 volts and second switch the higher voltages. To obtain filament voltages above 12.6 it is necessary to turn the first filament switch to "HIGH VOLTS", then the second switch is set to the voltage required. Until the first is in the "HIGH VOLTS" position the second switch is inoperative. ELEMENT SELECTOR "B-C-D" The element selector takes the form of ten lever switches, numbered from 1 to 10. Each of the switches from 1 to 9 represents the pins of a valve, the number above each switch from 1 to 9, corresponding to the pin numbers of the valve, according to standard valve numbering practice, and switch 10 represents the "TOP CAP". This form of switching enables the tester to switch any valve connection to any test position, or in the case of a valve having an internal connection or tapped heater to completely isolate a valve pin. The letters "B", "C" & "D" refer to the test positions to which valve elements may be switched. These test positions are given in the valve testing tables. When the lever switches are in the "NORMAL" position they are connected together to one side of the heater voltage. Normally all elements are left in this position with the exception of the element nearest the cathode and one heater connection. Position "B" is the heater connection and one heater pin is switched to this position. Position "C" is an open circuit position and any valve pin which has an internal connection which may tend to interfere with testing is switched into this position. Position "D" This is the "TEST" position. The element which is nearest to the cathode inside the valve is switched into this position and the tester applies a voltage to it for emission testing. Results are indicated directly on a three coloured scale marked good, questionable and bad. TEST SELECTOR "E" This switch is situated fourth from the left on the bottom of the front p