AWA 575P, 679P Diagram

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ELECTRICAL SPECIFICATIONS

Frequency Range	540-1600 Kc/s (555-187.5 Metres)
Intermediate Frequency	455 Kc/s
Battery Complement:
Model 575-P "A" Battery:-One "B" Battery:-One 9	7.5 volt, type 719 90 volt, type 490P
Model 679-P "A" Battery:One "B" Battery:One 9	9.0 volt, type 765 90 volt, type 490P

Battery Consumption:

Model 575-P ...... "A" Battery = 50 mA "B" Battery = 13 mA ("Full") = 8 mA ("Save") Model 679-P ...... "A" Battery = 50 mA "B" Battery = 13 mA ("Full") = 8 mA ("Save")

Power Unit Operation:

The receiver may be operated on the following voltage ranges by altering the transformer tappings:---

195-215 volts 216-235 volts 236-255 volts

With the switch in the A.C. position, the 6X4 is operated as a half wave rectifier with both plates connected to the chassis, which is negative for both "A" and "B" circuits. The transformer secondary voltage is applied between cathode and load.

With the switch in the "ACTIVATE" position, one rectifier plate and "A" battery negative are disconnected from the chassis and connected together, thus isolating the "A" and "B" circuits. The 6X4 is then used as two half-wave rectifiers with a common cathode.

Power Unit Frequency Range: 50-60 C.P.S. and 40 C.P.S.

A.C. Power Consumption ....................................
- 1T4 R.F. Amplifier (679-P only)
- 1R5 Converter
- 1T4 I.F. Amplifier
- 1S5 Detector, A.F. Amplifier, A.V.C.
- 3V4 Output 6X4 Rectifier

Loudspeaker (Permanent Magnet):

6 inch — Code No. AG52 Transformer — 31727A V.C. Impedance 3 ohms at 400 C.P.S.

Undistorted Power Output ..................................

Controls:

Tuning Control – right-hand end of cabinet. Volume Control – top left-hand end of cabinet. Power Selector Switch – bottom left-hand end of cabinet.

Drive Cord Replacement

The accompanying diagram shows the route of the cord and the method of attachment.

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Chassis Removal:

To remove the chassis from the cabinet open the back and disconnect the speaker cable and batteries. Unsolder the loop aerial leads and pull them back through the guides on the side of the cabinet.

Remove the knobs by pulling them straight off their spindles. Remove a screw under each knob when the cream link covers may be lifted off. The screw under each cover on being removed allows the chassis to be withdrawn.

When replacing the chassis pass the loop leads through the guides, keeping the green lead separate from the black and white, and solder the green lead to the panel so that it connects to the inside of the loop winding.

Note that the link covers are slightly different and must be replaced on the correct side, the one marked "TUNE" on the tuning spindle side and the one marked "VOL" on the volume control side.

ALIGNMENT PROCEDURE

Manufacturer's Setting of Adjustments:

The receiver is tested by the manufacturer with precision instruments and all adjusting screws are sealed. Re-alignment should be necessary only when components in tuned circuits are repaired or replaced, or when it is found that the seals over the adjusting screws are broken.

It is especially important that the adjustments should not be altered unless in association with the correct testing instruments listed below.

Under no circumstances should the plates of the ganged tuning capacitor be bent, as the unit is accurately aligned during manufacture and cannot be re-adjusted unless by skilled operators using special equipment.

For all alignment operations, keep the generator output as low as possible to avoid A.V.C. action and set the volume control in the maximum clockwise position.

Testing Instruments:

(1) A.W.A. Junior Signal Generator, type 2R7003.
(2) A.W.A. Modulated Oscillator, series J6726. If the modulated oscillator is used, connect a 0.25 megohm non-inductive resistor across the output terminals.
(3) A.W.A. Output Meter, type 2M8832.

ALIGNMENT TABLE-MODEL 575-P

Order	Connect "high" side of Generator to:	Tune Generator to:	Tune Receiver to:	Adjust for maximum peak output:
	NOTE: If loop leads pro them.	ptruding from the chassis ar	e disconnected, connect a 1	megohm resistor across
1 2	Grid of 1T4* (1.F. Amp.) Aerial Section of Gang* (Drive End)	455 Kc/s 455 Kc/s	Gang in full mesh Gang in full mesh	L7 and L6 Cores L5 and L4 Cores
	Repeat adjustments 1 ar With gang in full mesh, Replace the cover over removed from the loop lead to the inside of the before remainder of ali	nd 2 until the maximum o set the pointer to the sett the receiver chassis which leads and the leads then c e loop. The batteries must ignment is proceeded with	nutput is obtained. ting mark at the right-hand should then be fitted in th connected to the aerial in th t be in place in the cabine n.	end of the dial scale. he cabinet, the resistor he back lid, the green t and the back closed
3	Inductively coupled to Loop†	600 Kc/s	600 Kc/s (7ZL)	L.F. Osc. Core Adj. (L2)§‡
4	Inductively coupled to Loop†	1640 Kc/s	Gang fully open	H.F. Osc. Adj. (C3)§
5	Inductively coupled to Loop†	1500 Kc/s	1500 Kc/s (3AK)	H.F. Aer. Adj. (C8)§
Repeat adjustme	ents 3 and 5 until the ma	ximum output is obtained	l

* A 0.001 µF capacitor should be connected in series with the high side of the test instrument.

†A coil comprising 3 turns of 16 gauge D.C.C. wire and about 6 inches in diameter should be connected between the output terminals of the test instrument, placed co-axial with the loop and distant not less than 1 foot from it. ‡ Rock the tuning control back and forth through the signal.

§ These adjustments are accessible through 3 holes in the cabinet back.

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D.C. RESISTANCE OF WINDINGS MODEL 575-P

Winding	D.C. Resistance in ohms
Oscillator Coil:
Primary (L3)	1
Secondary (L2)	4
I.F. Transformer Windings	25
Loudspeaker Input Transformer (T1)
Primary	450
Secondary	*
Power Transformer (T2)
Primary	140
Secondary	100

* Less than 1 ohm.

The above readings were taken on a standard chassis, but substitution of materials during manufacture may cause variations, and it should not be assumed that a component is faulty if a slightly different reading is obtained.

SOCKET VOLTAGES-MODEL 575-P

	VALVES	Bias Volts	Screen to Chassis Volts:	Anode to Chassis Volts:	Anode Current mA:	Filament Volts:
1R5	Converter	*	48	48	0.5	1.3-1.4
174	I.F. Amp.	*	48	90	2.0	1.3-1.4
S2	Det., A.F. Amp., A.V.C.	*	25*	35*	0.1	1.3-1.4
3V4	Output	-4.5	90	88	6.5	2.6-2.8

* Cannot be measured with an ordinary voltmeter. Measured with no signal input. Volume Control maximum clockwise. A.C. Power Unit Operation:— H.T. Secondary Volts == 130V A.C. 6X4 Cathode to Chassis Volts == 120V D.C. Heater Volts == 6.3V A.C.

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ALIGNMENT TABLE-MODEL 679-P

Order	Connect "high" side of Generator to:	Tune Generator to:	Tune Receiver to:	Adjust for maximum peak output:
	NOTE: If loop leads prot them.	ruding from the chassis are	e disconnected, connect a 1	megohm resistor across
1	Grid of 1T4* (I.F. Amp.)	455 Kc/s	Gang in full mesh	L9 and L8 Cores
2	Grid of 1R5* (Rear Section of Gang)	455 Kc/s	Gang in full mesh	L7 and L6 Cores
	Repeat adjustments 1 and With gang in full mesh, se Replace the cover over th the resistor from the loop to the inside of the loop. alignment of aerial circuits Connect a 10,000 ohms re	2 until the maximum o et the pointer to the settir he receiver chassis which leads and connect them t . The batteries must be ir sistor from the rear sectio	utput is obtained. ng mark at the right-hand e should then be fitted in o the aerial in the cabinet n place in the cabinet and on of the gang to chassis.	end of the dial scale. the cabinet, remove back, the green lead the back closed for
3	Inductively coupled to	600 Kc/s	600 Kc/s (7ZL)	L.F. Osc. Core Adj. (L4)§‡
4	Inductively coupled to	1640 Kc/s	Gang fully open	H.F. Osc. Adj. (C9)¶
5	Inductively coupled to loop†	1500 Kc/s	1500 Kc/s (3AK)	H.F. Aer. Adj. (C2)§
	Repeat adjustments 3 an Remove the 10,000 ohm	nd 5 until maximum outp resistor.	ut is obtained.
6	Inductively coupled to	600 Kc/s	600 Kc/s (7ZL)	L.F. R.F. Core Adj. (L3)§
7	Inductively coupled to loop†	1500 Kc/s	1500 Kc/s (3AK)	H.F. R.F. Adj. (C7)§
	Repeat adjustments 6 an	d 7 until maximum output	is obtained and finally che	ck adjustments 3 and 5.

* A 0.001 µF capacitor should be connected in series with the high side of the test instrument.
† A coil comprising 3 turns of 16 gauge D.C.C. wire and about 6 inches in diameter should be connected between the output terminals of the test instrument, placed co-axial with the loop and distant not less than 1 foot from it.
‡ Rock the tuning control back and forth through the signal.
& These adjustments are accessible through 4 holes in the cabinet back.
I Open the back to make this adjustment and then close to complete alignment.

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Abs</th 1 13 31835 Part No. 30785 27526 3155 31727A 5835 25837 25837 0785 12-445 μμ 3-25 μμF 0.05 μF F 5-50 μμF 10.0 R 200 C 200 PL1 BBI3 BBI3 Part No. Fig. No. 81841 80784 80777 27324 27351 27526 30785 Vound 5%) 10% 4 ohms 22,000 ohms 47,000 ohms 10 megohms 1,100 ohms 1,100 ohms 1,200 ohms 1,200 ohms 470 ohms 0.47 megohm 1.0 megohm 470 ohms 330 ohms 330 ohms R12 R14 R15 R17 R12 R22 000000

CIRCUIT CODE – MODEL 679-F

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D.C. RESISTANCE OF WINDINGS MODEL 679-P

Winding	D.C. Resistance in ohms
R.F. Coil:
Primary (L2)	100
Secondary (L3)	4
Oscillator Coil:
Primary (L5)	1
Secondary (L4)	4
1st I.F. Transformer Windings	25
2nd I.F. Transformer Windings	20
Loudspeaker Input Transformer (T1)
Primary	450
Secondary	*
Power Transformer (T2)
Primary	140
Secondary	100

* Less than 1 ohm.

SOCKET VOLTAGES-MODEL 679-P

	VALVES	Bias Volts	Screen to Chassis Volts:	Anode to Chassis Volts:	Anode Current mA:	Filament Volts:
1T4	R.F. Amp	*	40	90	0.5	1.3-1.4
1R5	Converter	*	40	40	0.5	1.3-1.4
1T4	I.F. Amp.	*	40	90	1.5	1.3-1.4
1$5	Det., A.F. Amp., A.V.C.	*	25*	35*	0.1	1.3-1.4
3V4	Output	-5.0	9 0	88	6.5	2.6-2.8

* Cannot be measured with an ordinary voltmeter. Measured with no signal input. Volume Control maximum clockwise. A.C. Power Unit Operation:— H.T. Secondary Volts = 130V A.C. 6X4 Cathode to Chassis Volts = 120V D.C. Heater Volts = 6.3V A.C.

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CUIT
RCUIT

Loca	B14	D13	ទីរ	815	E15	H7	H7	D10	D14	C12	G7	G7	B2	E5	A8	D8	80	G12	G12	G12	D8	E9	D4		HIO	F13					D13		E1 E17
ig. No.	7	0	-	01	0	-	-	7	7	7	-	-	ы	7	7	7	7		-	-	ы	7	7		-	-					-		20
Part No. F			18621	27526																					31727A	25835	25837		AG52		31835
Description	470 μμF padder ± 2½%	68 µµF silvered mica	12-445 μμF tuning	3-25 μμF trimmer	0.1 µF paper 200V working	47 µµF silvered mica (in 1st I.F.)	47 µµF silvered mica (in 1st 1.F.)	0.01 µF paper 600V working	0.05 μF paper 200V working	6.8 µµF ceramic	47 Mut Silvered mica (in 2nd I.F.)	47 µµF silvered mica (in 2nd I.F.)	200 µµF mica	0.01 µF paper 600V working	0.01 µF paper 600V working	0.05 µF paper 200V working	100 μμF silvered mica	50 μF 150 W.V. electrolytic	40 µF 150 W.V. electrolytic	40 µF 25 W.V. electrolytic	0.01 µF paper 600V working	400 µF 12 P.V. electrolytic	0.0025 µF paper 600V working	TRANSFORMERS	Loudspeaker Transformer	Power Transformer, 50 c.p.s.	40 c.p.s.	IOUDSPEAKEP	6" permanent magnet		Power Selector	PILOT LAMP	2.5V 0.2 Amp. M.E.S. 2.5V 0.2 Amp. M.E.S.
Code No.	C5	C6	0	80	e S	C10	1D	C12	C13	C14	C15	C16	C17	C18	C19	C20	C21	C22A	C22B	C22C	C23	C24	C25		I	12	ļ				IS		PL1 PL2

Location			B13	H7	67			D14	E13	F14	D12	B12	D5	CII	B12	ប	C10	D7	BB		F5		E13	C14	CI3	ဗီ	B7	9 C	52		512	2 8	B14 G4
Fig. No. Location			2 B13	1 H7	1 67			2 D14	2 E13	2 F14	2 D12	2 B12	2 D5	2 C11	2 B12	2 2	2 C10	2 D7	2 B8		2 F6		1 E13	1 C14	CI3	2 C	2 B7	2 6	2 7 4 7 7	4	C13	1 53	2 B14 1 G4
Part No. Fig. No. Location		31841	30777 2 B13	27324 l H7	27324 I G7			2 D14	2 E13	2 F14	2 D12	2 B12	2 D5	2 C11	2 B12	28311 2 C3	2 C10	2 D7	2 B8	þ	2 F6	T	1 E13	1 C14	1 C13	2 C6	2 87	2 5	2 (4	4	C13	- 1	27526 2 B14 18621 1 G4
Description Part No. Fig. No. Location	TORS	Aerial Coil 31841	tor Coil 540-1600 Kc/s 30777 2 B13	Transformer 27324 1 H7	F. Transformer 27324 1 G7		ORS	egohms ½ watt ± 10% 2 D14	egohm 1 ,, ,, , 2 E13	hms } // 2 Fi4	egohms ½ ,, ,, 2 D12	egohms ½ // 2 B12	1s ½ , 2 D5	ohms ½ ,, 5% 2 C11	ohms } ,, ,, 10% 2 B12	iegohm Volume Control 28311 2 C3	egohms ½ watt ± 10% 2 C10	3gohms 1 // 2 D7	negohm }	ohms 3 ,, (Wirewound	± 5%) 2 F6	ohms 3 ,, (Wirewound	± 5%) 1 E13	ohms 1 ,, ,, 10% 1 CI4	hms 1 1 C13	regohm 1 , 2 C6	hms 1 ,, ,, , 2 B7	hms 7	ohms ∃ ,	ms 7	CITORS	ur paper zuuv working z cus mica 1 E3	uuf trimmer 27526 2 B14 uuf tunina 18621 1 G4
Description Part No. Fig. No. Location	INDUCTORS	Loop Aerial Coil 31841	Oscillator Coil 540-1600 Kc/s 30777 2 B13	1st I.F. Transformer 27324 1 H7	2nd I.F. Transformer 27324 1 G7		RESISTORS	3.3 megohms ½ watt ± 10% 2 D14	0.1 megohm ¹ / ₂ 2 E13	820 ohms ½ // // 2 F14	4.7 megohms ½ // // 2 D12	3.3 megohms ½ // // 2 B12	4 ohms ½ ,, ,, . 2 D5	13,000 ohms ½ ,, 5% 2 C11	47,000 ohms ½ ,, 10% 2 B12	1.0 megohm Volume Control 28311 2 C3	3.3 megohms ½ watt ± 10% 2 C10	10 megohms ¹ / ₂ ,, ,, , 2 D7	0.47 megohm ½ ,, ,, 2 B8	1,100 ohms 3 ,, (Wirewound	± 5%) 2 F6	1,200 ohms 3 ,. (Wirewound	± 5%) 1 E13	1,800 ohms 1 ,, 10% 1 C14	470 ohms 1	1.0 megohm 1 2 C6	470 ohms ¹ / ₂ // // 2 B7	820 ohms ½ // // 2 E5	330 ohms ½ ,, ,, 2 C4	30 onms 2	CAPACITORS	0.00 µr paper 2007 working 2 3 3	3-25 μμF trimmer 27526 2 B14 12-445 μμF trimina 18621 1 G4