THE PALEC MODELS VCT/3 VALVE & CIRCUIT TESTER AND ET/4 VALVE TESTER

GENERAL DESCRIPTION:
The VCT/3 is a combination of a newly developed emission type valve tester with universal element selector and the Palec M32 Multimeter with ranges and functions as below.  The ET/4 Tester embodies valve testing functions only.

Valve Testing 	(a) 	Inter-element short circuits.
			(b)	Filament continuity.
			(c)	Valve emission.
Multimeter

	Volts D.C.		0/3,10, 30, 100, 300, 1000. (1000 ohms per volt).

	Millivolts D.C.		0/100 (for use with external shunt) to extend D.C. current ranges.

Volts A.C.		0/3, 10, 30, 100, 300, 1000. (1000 ohms. per volt).

Decibels.		-10/01+10, +101+30, +301+50. 0db. = 1 rn.W. in 600 ohms.
			- 17/01+3,  +37+23, +231+43. 0db.	= 6 m.W. in 600 ohms.

Amperes D.C		0/1, 10.

Milliamperes D.C.	0/1, 3, 10, 30, 100, 300.

Milliamperes A.C. 	0/1 (for use with External Current Transformer).

Ohms.			0/15/5000 ( x 1), 0/1500/0.5 M x100)
			0/0.15 M /15M    ( x 1000).  Internal Battery all ranges.

VALVE TESTER OPERATION

Preliminary

1 -It should be noted that the dual functions of Filament voltage and Multimeter Range Selection is effected by the two switches located below the meter.  Filament voltage values are printed in black on an aluminium background, multimeter ranges in aluminium on a black background. Neither the valve testing nor the multimeter section will function unless all switches are set in the manner indicated in the following instructions.

	2.-The Valve pin Selector Is a feature of the Palec VCT/3 permitting complete flexibility in element selection. This comprises ten, 1 pole 4 position switches independently controlled, allowing any number of elements up to 10 to be switched to any of 4 positions marked, N, E, Fl, F2.  "N" being Neutral, or completely isolated, "E" for Emission to which the element adjacent to the Filament or Cathode is switched, Fl and F2 being the two filament positions. Fl being linked to all elements except the grid In multi-element tubes and the plate in rectifiers and diodes.

		3.- 	1.	Set both Filament Voltage switches pointing downwards to the arrows indicating                         			"Set here for R.H. Fil. Sw." and "Set here for L.H. Fil. Sw.

		2.	Place all Valve Pin Selectors to position N (Neutral).

			3.	Set Function Selector to LINE.

		4.	Plug power supply lead into a 215-265 Volt 40-60 Cycle power outlet.
   	(N.B.-When attaching a plug to the tester it is important to be sure that the metal                             		case and panel is earthed, either by means of a 3-pin plug or separately, -the green                                                                                                                      		lead is earth).

		5.	Turn Line Adj. control until meter pointer coincides with 4~Line Check" position at                                                                			centre scale.

Filament Continuity

		6.	Set Function Selector to SHORTS.

		7.	Set Filament Volts switches to the value indicated on valve testing charts in                                                 			column headed "Filament Volts".
			N.B.-Where the filament voltage for the valve to be tested is from 0.6 to 12.GV.                                                            			inclusive, the Right hand Switch should be set to the arrow indicating "Set here for                                                        			L.H. fil. Sw.", the Left hand switch being set to the appropriate voltage. Where the                                                                                                                                         			filament voltage is from 25 to 117V. inclusive, the Left hand switch should be set to                                                             			the arrow indicating "Set here for Right. Fil. Sw. and the Right hand switch set to the                                                                        			appropriate voltage.

			8.	Insert valve to be tested in appropriate socket.

			9.	Set numbered valve pin selector lever to F2 position as indicated in columns                                                          			numbered I - 10 in valve testing chart.

			10.	Set numbered valve pin selector levers indicated under Fl* on chart to position E.  A                                                                                                                                                                                        		             glow on the neon tube indicates filament continuity.

Element Shorts
		11.	Move valve pin selector levers marked FI* (used in 10 above) to position Fl.

		12.	Move each remaining Valve Pin Selector lever marked Fl in chart to E. A glow in                                                                           			the neon tube indicates a short circuit between elements. when there is no indication                                                                                                                              			of a short, the Fl levers should be carried through to Fl.

		13.	Place Valve pin selector marked as E on chart at position E again noting that the                                                                                       			neon glow indicates a short circuited element.

Valve Merit or Emission Test
			14.	Set Function Selector to MERIT setting 1, 2 or 3 as indicated on chart.

			15.	Set range control to the setting as chart.

			16.	Press Merit button when valve condition will be indicated on "Good-Replace" scale                                                                                                                   			of meter.

N.B.-When more than one test is to be given on a valve, the Valve Pin Selectors, Function Switch (Merit Section), and range control setting must all be set in accordance with the valve chart for each test.  Where line fluctuations are suspected the "line check" procedure should be repeated before final merit check.

Procedure for Testing Non-Listed Valves
The VCT 3 will test any type of Radio Receiver Valve if it has a filament or heater voltage within the range provided, not more than 10 element connections, and it will plug into a socket on the tester. It is our endeavor to keep up to date with supplementary issues of valve charts; however, if a valve has to be tested which is not listed, the following procedure should be followed:

Instructions 1 - 13 should be followed as set out except that F1* and F2 would to be ascertained from a valve manual, care has to be exercised to avoid con-between heater and double supported elements, which would appear to be similar ohmmeter test or filament continuity test.

From the valve base diagram the internal connections can be ascertained. The filaments being switched to Fl and F2, adjacent element to cathode switched to E by its appropriately numbered lever, all other elements switched to Fl. Spare pins or extra element support; switched to N.

With the range control gradually raised from zero with Merit button pressed  the function switch set to Merit 1,2 or 3 (1 for diodes, 2 for battery operated valves, 3 for rectifier and other valves), the meter pointer will  move across the scale to "Good" with a known "good" valve. The range control position corresponding to about 80% full scale, should be noted and applied to other valves of the same type.

MULTIMETER OPERATION:

Preliminary
1.Sset Function Selector to "Multimeter" and the two Range switches to the appropriate ranges. N.B.-The multimeter will not function with either of these switches set to the arrow position as for valve testing.

2.-D.C. Volts.  Connect test leads to terminals noting polarity.  Set right hand switch to the range required. To avoid overloading it is advisable to ascertain the order of the voltage under test on a high range, then changing to a lower range for closer indication.

3.-A.C. Volts. As above with right hand switch set to V. The 0/3 and 0/10 Volt ranges indicate on the Red Scales. With the A.C. Volt ranges the necessity of avoiding overloading is stressed, due to the danger  of damage to the copper oxide rectifier used on A.C.

4.-Decibels. As A.C. Volts, use upper or lower Green Scale depending upon zero reference level. The terms +0db, +20db, +40db should be added algebraically to the meter reading.

5.-Milliamperes A.C. As A~C. volts but with Left-hand switch set to I M.A. A.C. only, EXT. C. Trans. This range is provided for use with external current transformers for A.C. current measurement. These items are available to cover a wide range of current values.

6.-D.C. Current. Turn Left-hand switch to Amps M.A., D.C. and Right-hand switch to the range required, avoid overloading as above. For measuring current above 10 Amperes D.C. an external 100 Millivolt shunt should be used in conjunction with the 0/1 Milliampere range, which is also 0/100 Millivolts.
External shunts can be supplied to cover a wide range of current values

7.-Resistance. Set Right-hand switch to "Ohms" and the Left-hand switch to C) x 1, fz x 100, (2 x 1000 as required. Contact test leads firmly together so that terminals are short circuited. The meter pointer will move across the scale. Using the "Ohms adj." Control bring the pointer to full scale, or ohms zero position. The test leads are then connected to the unknown resistance. The Value indicated on the Ohms scale should be multiplied by the factor indicated on the left-hand switch to obtain the resistance value in Ohms.
When full scale cannot be obtained with the test leads shorted the internal batteries should be replaced. These are:
 x 1,  x 100, 2 - 1.5 VOLT EVEREADY TYPE 950. PEP No.2. 
 x 1000, 1 - 30 VOLT EVEREADY TYPE 430.

N.B.-Do not attempt to test resistors with current flowing from an external source.