ELECTRICAL SPECIFICATIONS.
FREQUENCY RANGE ...... Medium Wave 1600-550 Kc. (187.5-545M) Short Wave 22-7 Mc. (13.6-43M)
INTERMEDIATE FREQUENCY 455 Kc.
POWER SUPPLY RATING ...... 200-260 volts, 50-60 C.P.S. .(Models are produced with other voltage and frequency ratings)
POWER CONSUMPTION .... 60 watts
DIAL LAMP (2) ...... 6.3 volts, 0.25 amp. M.E.S.
VALVE COMPLEMENT— (1) 6J8G Converter
(1) 6J8G Converter (3) 6B6G Det., A.V.C. and A.F. Amp. (2) 6U7G I.F. Amplifier (4) 6V6GT/G Output (5) 5Y3GT/G Rectifier
LOUDSPEAKER--Model 607-T: Model 705-C: 7 inch-Code No. AW4 12 inch-Code No. AS13 Transformer-XA1 Transformer-TX20 V.C. Impedance-3 ohms at V.C. Impedance-2.2 ohms 400 C.P.S. at 400 C.P.S. Field-1,500 ohms Field-1,500 ohms
UNDISTORTED POWER OUTPUT ...... 4.5 watts
MECHANICAL SPECIFICATIONS.
| Height | Width | Depth | |
|---|---|---|---|
| Cabinet Dimensions (inches)- | - | ||
| 607-T | . 11 | 24 | 101 |
| 705-C | . 33 ↓ | 30 1 | 13 |
| Chassis Base Dimensions | . 3 | 15 | 6 1 |
| Overall Chassis Height (inche | əs) | 8 |
| Height | Width | Depth | ||||
|---|---|---|---|---|---|---|
| Weight (nett Ibs.)— | · | |||||
| 607-T | 34 | |||||
| 705-C | •••••• | 74 | ||||
| Carton Dimensions (inches)— | ||||||
| 607-T | 121 | 25 | 12 | |||
| 705-C | 351 | 32 | 141 | |||
| Cabinet Finish | Walnut | Veneer | ||||
GENERAL DESCRIPTION.
The models 607-T and 705-C are table and console models, respectively, and employ the same chassis.
Features of design include: Tropic-proof construction, power switch on chassis, phono-range switch, automatic volume control, continuously variable tone control, straight-
line, edge-lighted dial with metropolitan stations printed in g-inch high characters, magnetite cores in I.F. transformers and broadcast oscillator coil, air-dielectric trimming capacitors, broadcast tuning range extended to 1,600 kc. to permit reception of proposed stations above 1,500 kc.
ALIGNMENT PROCEDURE.
Manufacturer's Setting of Adjustments.
The receiver is tested by the manufacturers 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 have been 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 specialised equipment.
For all alignment operations, connect the ''low'' side of the signal generator to the receiver chassis, and keep the generator output as low as possible to avoid A.V.C. action. Also, keep the volume control in the maximum clockwise position.
Testing Instruments.
- (1) A.W.A. Junior Signal Generator, type 2R3911
- (2) A.W.A. Modulated Oscillator, type J6726.
If the modulated oscillator is used, connect a 0.25 megohm non-inductive resistor across the output terminals, and, for short-wave alignment, an additional 400 ohms non-inductive resistor in series with the "high" output lead of the instrument.
(3) Output Meter.
The instrument recommended should have an output impedance of 5,000 ohms and a range of 5-3,000 milliwatts. The meter should be connected across the primary of the loudspeaker transformer with the voice-coil of the loudspeaker open-circuit.
If the output meter used is one which does not impress a load on the anode circuit of the output valve, it will not be necessary to open-circuit the voice-coil.
| Order |
Connect "high" side
of Generator to: |
Tune Generator
to: |
Set Receiver Drive
Drum Scale to: |
Adjust for Maximum
peak output: |
|||
|---|---|---|---|---|---|---|---|
| I | 6J8G Grid* | 455 Kc. | 0 ° | LI3 Core | |||
| 2 | 6J8G Grid* | 455 Kc. | 0 | L12 Core | |||
| 3 | 6J8G Grid* | 455 Kc. | 0 | LII Core | |||
| 4 | 6J8G Grid* | 455 Kc. | 0 | LIO Core | |||
| Repeat the above adjustments until the maximum output is obtained | |||||||
| 5 | Aerial Term | 600 Kc. | 18 | L.F. Osc. Core Adj. (L7)† | |||
| 6 | Aerial Term | 1500 Kc. | 154 | H.F. Osc. Adj. (C5) | |||
| 7 | Aerial Term | 1500 Kc. | 154 | H.F. Aer. Adj. (C2) | |||
| Repeat Adjustments 5, 6 and 7 | |||||||
| 8 | | Aerial Term | 20 Mc. | 157 | | H.F. Osc. Adj. (C6)‡ | |||
| 9 | Aerial Term | 20 Mc. | 157 | H.F. Aer. Adj. (C3)§ | |||
ALIGNMENT TABLE.
* With grid clip connected. A 0.001 uF capacitor should be connected in series with the "high" side of the test instrument. † Rock the tuning control back and forth through the signal.
‡ Use minimum capacity peak if two can be obtained. Check to determine that C6 has been adjusted to correct peak by tuning the receiver to approximately 19.09 Mc., where a weaker signal should be received.
§ Use maximum capacity peak if two-can be obtained.
CHASSIS (TOP VIEW).
NOTE: The I.F. transformer primary cores are adjusted from underneath the chassis.
Loudspeaker Service.
It is inadvisable to attempt loudspeaker repairs other than adjustment of the voice coil and replacement of the transformer. The fitting of a new cone or the replacement of a field winding should be done only by Service Departments suitably equipped to do the work.
To centre the voice coil first remove the dust cover. To do this, use a very sharp razor blade and cut the centre out of the dust cover, cutting just inside the edge of the voice coil former, which can be felt with the finger. Do not attempt to tear the cover from the cone. Loosen the suspension screws, insert three narrow paper "feelers" in the gap and re-tighten the suspension screws. The "feelers" should be approximately 3/16 inch wide and 0.006 inch thick.
After adjusting, test the loudspeaker, and, if satisfactory, fasten a replacement dust cover, part number 7677, in place with latex rubber cement.
Connection to Power Supply.
The receiver should not be connected to any circuit supplying other than alternating current from 200 to 260 volts and at the frequency stated on the label within the cabinet. The power supply connection panel is shown in the accompanying diagram, and for 230 to 260-volt operation the input leads from the power switch (S2) should be connected to tags B and G. For operation on voltages below 230 connection should be made to tags B and W.
"Service Window."
A "Service Window" is provided in the base of the table model cabinet. The "Window" is normally covered with a perforated grille fastened by four knurled nuts. With the grille removed, it is possible to perform most servicing operations without removing the chassis from the cabinet.
Chassis Removal and Replacement.
Remove the control knobs. The knobs on the front of the cabinet are each held by a set screw. To remove the Tuning Control knob at the side of the cabinet, proceed as follows:—
Table Model: The knob pulls straight off.
Console Model: Loosen the screws in the spindle coupling and part the spindle.
- (2) Disconnect the pointer from the dial drive cord, by unscrewing the thumb nut, and disconnect the cable from the loudspeaker. Also, disconnect the yellow and black dial lamp leads from the chassis.
- (3) Four bolts hold the chassis in the cabinet. Remove these and withdraw the chassis.
On replacing the chassis in the cabinet, care must be taken to connect the dial pointer to the dial drive cord correctly, as follows:—
- (1) Turn the Tuning Control fully anti-clockwise.
- (2) Bring the dial pointer to a position opposite a setting mark on the dial scale, below, and approximately 1/16 inch to the left of 2CR.
- (3) Connect the pointer to the top drive cord and tighten the thumb-screw.
SOCKET VOLTAGES AND CURRENTS
| Valve |
Cathode to
Chassis Volts |
Control Grid
to Chassis Volts |
Screen Grid
to Chassis Volts |
Plate to
Chassis Volts |
Plate
Current mA |
Heater
Volts |
|---|---|---|---|---|---|---|
| 6J8G Converter, M.W | 0 | -3* | 75 | 250 | 1.0 | 6.3 |
| S.W | 3 | 0 | 75 | 250 | 1.2 | 6.3 |
| Oscillator | 115 | 5.0 | ||||
| 6U7G I.F. Amplifier | 0 | -3* | 75 | 250 | 6.0 | 6.3 |
| 6B6G Detector | 0 | 0 | 100* | 0.5 | 6.3 | |
| 6V6GT/G Output | 13 | 0 | 250 | 230 | 45 | 6.3 |
| 5Y3GT/G Rectifier | 350 AC | 5.0 |
Total H.T. Current - 70 mA.
* These readings may vary, depending on the resistance of the voltmeter used.
Voltages and currents measured at 240 volts A.C. supply. No signal input. Volume Control, maximum clockwise. Voltmeter, 1,000 ohms per volt. Measurements taken on highest scale, giving accurate readable deflection.
| Winding | D.C. Resistance in ohms |
|---|---|
|
Aerial Coil (M.W.)—
Primary (L2) Secondary (L3) |
10.5
3.5 |
|
Aerial Coil (S.W.—
Primary (L4) Secondary (L5) |
2
* |
|
Oscillator Coil (M.W.)—
Primary (L6) Secondary (L7) |
|
6 |
|
Oscillator Coil (S.W.)—
Primary Secondary |
* |
| I.F. Transformer Windings | 7.5 |
| I.F. Filter (LI) | 17.5† |
|
Power Transformer (TI)—
Primary Secondary |
16
500 |
|
Loudspeaker Input Transformer (T2)—
XAI Primary XAI Secondary TX20 Primary |
500
* 420 |
| IX20 Secondary | * |
D.C. RESISTANCE OF WINDINGS.
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.
* Less than I ohm.
† In some receivers this reading may be as high as 60 ohms.
Tuning Drive Cord Replacement.
The accompanying diagram shows the route of the cord and the method of attachment. Whilst fitting the cord, keep it taut and adjust the length so that the tension spring measures approximately 2 inches long when fitted. The spring should be sheathed to prevent in from rattling against the drum.
MECHANICAL REPLACEMENT PARTS.
| ltem | Part No |
|---|---|
| Cabinet, console | C68 |
| Cabinet, table | C73 |
| Cable, loudspeaker— | |
| Console Model | 6465 |
| Table Model | 17822 |
| Cable, pick-up | 19036 |
| Cable, power | 209 |
| Cable, Volume Control | 7328 |
| Chassis end | 8411 |
| Clip, grid | 7459 |
| Cone Assembly, loudspeaker— | |
| Туре АW4 | 9356 |
| Туре А$ІЗ | 7071 |
| Dial frame assembly | 19622 |
| Dial Scale | 19032 |
| Drum, drive | 9090 |
| Item | Part N |
|---|---|
| Dust cover, loudspeaker | 7677 |
| Mount plate assembly, tuning drive | 19011 |
| Pulleys, brass | 1730 |
| Screen, I.F. Transformer | 3351 |
| cap | 837 2 |
| Screen, valve | 8147 |
| cap | 8148 |
| register | 4733 |
| Socket, valve | 4704 |
| Socket, valve, cushion | 7326 |
| Spindle, tuning drive | 19012 |
| Spring, drive tension | 6641 |
| Strip, tag, I-way | 76 2 8 |
| 3-way | 4251 |
| 7-way | 9879 |
CIRCUIT DIAGRAM
CIRCUIT CODE
|
Circuit
Code No. |
Description |
Stock Code
or Part No. |
Circuit
Code No. |
Description |
Stock Code
or Part No. |
Circuit
Code No. |
Description |
Stock Code
or Part No. |
|---|---|---|---|---|---|---|---|---|
| INDUCTORS. | C20 | 0.01 uF paper, 600 V | /. | R7 |
50,000 ohms,
|
600, 315 | ||
| LI |
I.F. filter choke (in-
cluding CI) |
9382 | C21 |
working
4 uuF mica |
228, 301
224, 233 |
R8
R9 |
20,000 ohms, ½ watt | 600, 307 |
| L2, L3 | Aerial coil, 550-1600 | Kc. 7974 | C22 | 70 uuF silvered mica | 226, 460 | RIO | Not used | 600, 349 |
| L4, L5 | Aerial coil, 7-22 Mc. | 9569 | C23 | 70 uuF silvered mica | 226, 460 | RII | Not used | |
| L6, L7 | Oscillator coil, 550- | C24 | 110 uuF mica | |32||† | R12 | 0.5 megohm volum | e | |
| 1600 Kc. | 9206 | C25 | 110 uuF mica | 13211† | control | 7263 | ||
| _L8, L9 |
Oscillator coil, 7-22
Mc. |
9205 | C26 |
0.01 uF paper, 600 V
working |
′.
228, 301 |
R I 3 |
10 megohms, 1 wat
600,561 |
t
or 600, 761 |
| LIO, LII | lst I.F. transformer 82 | 86-Z, 8282* | C27 | 0.5 uF paper, 400 V | ' . | R14 | 1.6 megohms, ½ watt | 600, 345 |
| LI2, LI3 | 2nd I.F. transformer 82 | 287-Z, 8281* | working | 228, 135 | R15 | 50,000 ohms, ½ watt | 600, 315 | |
| LI4 | Loudspeaker field coil, | C28 | 50 uuF mica | 224, 255 | R16 | 250 ohms, 3 watts | ||
| C29 | 200 uuF mica | 224, 267 | D I 7 | w.w. | 602, 369 | |||
| CAPACITORS. | C30 | 0.02 uF paper, 600 V | 50,000 ohms, ½ watt | 600, 315 | ||||
| CI | 50 uuF silvered mica | 226, 155 | C31 | 25 uE 40 PV elec | 220, 307 | RIO | 0.4 megohms, ½ watt | 600, 333 |
| C2 | 2-20 uuF air trimmer | 3661 | 031 | trolytic |
-
ET10769 |
R20 | 0.1 megonm, ½ watt | 600, 321 |
| C3 | 6-24 uuF air trimmer | 5435A | C32 | 0.05 uF paper, 400 V | ' . | 1120 | control | 19621 |
| C4 | 0.05 uF paper, 400 V. | 220 115 | working | 228, 115 | R21 | 0.25 megohm, I watt | ||
| C5 | Working |
220, 115
3411B |
C33 | 1500 uuF mica | |32|3† | 600, 529 | or 600, 729 | |
| C6 | 2-10 uuE air trimmer | 3458 | C34 | 0.005 uF paper, 600 \ | /. | R22 |
20,000 ohms, I watt
600 507 |
or 600 707 |
| C7 | 0.05 uE paper, 400 V. | 5050 | Car | working | 228, 295 | R23 | 40 ohms. 3 watts | 602 353 |
| 0, | working | 228, 115 | C35 |
0.0025 uF paper, 600 V
working |
'.
228 289 |
002 333 | ||
| C8 | 4000 uuF mica 🛨 | C36 | 0.5 uE paper 400 V | , | TRANSFORMERS. | |||
| 2½% (padder) | 13213† | working | 228, 115 | TI | Power transformer, | |||
| C9 | 12-430 uuF variable | 19010 | C37 | 16 uF, 525 P.V. elec | - | 50-60 C.P.S. | 11344A | |
| CIO | 490 uuE mica - | 1,010 | trolytic | ET10783 | 40 C.P.S. | 11346A | ||
| 2½% (padder) | 13212† | C38 | 8 uF, 525 P.V. elec | - | Τ2 | Loudspeaker trans- | ||
| CII | 70 uuF mica | |32||† | trolytic | EE1015 | former (table mod | lel) XAI | ||
| C12 | 12-430 uuF variable | RESISTORS. | Loudspeaker trans- | t the management | ||||
| 0.10 | tuning (ganged) | 19010 | RI | 320 ohms, 🚽 watt | 600, 271 | former (console mo | del) IX20 | |
| 4 uuF mica | 224, 233 | R2 | 50,000 ohms, 🚽 watt | 600, 315 | SWITCHES. | |||
| working | 228, 121 | R3 | 25,000 ohms, 1 watt | SI | Phono-range, 3 wafer | , | ||
| C15 | 70 uuF silvered mica | 226, 460 | 600, 509 | or 600, 709 | rotary | 9804 | ||
| C16 | 70 uuF silvered mica | 226, 460 | R4 | 25,000 ohms, 2 watts | wafer I | 9804/1 | ||
| C17 | 0.1 uF paper, 400 V. | • | 600, 515 · | or 600, 715 | wafer 2 | 9804/2 | ||
| working | 228, 121 | DE | r in parallel) | wafer 3 | 9804/3 | |||
| C18 | 0.01 uF paper, 600 V. | 228 301 | K5 |
20,000 onms, 1 watt
600. 507 |
or 600. 707 | (NOTE: Wafers numb | bered | |
| CI9 | 220, 301 | R6 | 0.1 meachm. ± watt | , | 52 | Trom tront of chase | 515) | |
| 0.7 | working | 228, 121 | 600, 521 | or 600, 721 | JL |
rower switch, D.P.S.I.
rotary |
20007 | |
| - | • |
* Part number of winding only.
† Capacitance and tolerance (if shown) to be quoted.
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