Page 1: ...ULT E amil 0 TtJE PHCNE ...
Page 2: ...as a field for Nception with that unknown factor the ether to add to the thrill of the game Further on the ultra short waves which are coming into greater prominence and exists a whole Held for t 4titiine experiment at present comparatively unexplored We hope that this third number of the Eddystone Short Wave Manual will prove of help and interest to those who wish to join the ranks of radio enthu...
Page 3: ...Transmitter 21 to 23 5 Valve Short Wave Super Heterodyne Receiver Battery Model 24 to 27 Ultra Short Wave Radio Telephone 28 to 32 A Modulated Oscillator 33 One Valve Short Wave High Frequency Amplifier or Short Wave Converter 34 to 38 Solder Your Wireless Set 39 Two Valve Transceiver 40 41 Absorption Waveme ter 42 Wavelength or Frequency 42 Valve Bases 413 Short Wave Broadcast Stations 44 COPYRIG...
Page 4: ... H F Pentode valve followed by an audio stage which can use either triode or pentode valve as desired The aerial input circuit although simple in design was only satis factorily developed after protracted experi ments on many different types of aerials It ensures complete freedom from tuning blind spots thus saving the extra cost of an H F stage which is the generally accepted medium for overcomin...
Page 5: ... specified or alternatively one of the three pentode valves listed below The average total number of milliamps for any of the pentodes or triodes are given in the right hand column below from which it will be seen that the use of the pentode type of output does not increase the consumption of the receiver but does in practice consider ably add to the signal strength A five pin valveholder is fitte...
Page 6: ... Tuning Condenser 10 Moving Plates of Tuning Condenser to Soldering Tag E 11 Bottom Terminal Moving Plates of Tank Condenser to Soldering Tag E 12 Socket No 2 of Coil Base to Soldering Tag E I3 Socket No 5 of Coil Base to Reaction Trimmer ARTe4 AERIAL 1 OiNtINICe 14 One end of 3 megohin Leak to Socket No 2 of Vt 15 Other end of Leak to Socket No 5 of VI 16 Socket No 3 of VI to Soldering Tag E 17 S...
Page 7: ...02 infd Condenser to Grid Socket of V2 28 Other end of this Condenser to Reaction Trimmer 20 Same Connection of Trimmer through B in chassis to Top Cap of 30 One end of 100 000 ohms Resistance to same Side of Trimmer 31 Other end of 100 00 1 ohms Resistance to Phone Socket 32 End Tag of Reaction Control to Soldering Tag E 33 Tag of Reaction Control to 40 000 ohms Resistance 34 Remaining end of 40 ...
Page 8: ... H T supply SP2 Anode Current approx 0 25 m a knode Voltage 90 volts P220 Anode Current 3 m a Anode Voltage 115 volts Potentiometer Current 1 25 m a Total Current 4 5 m a at 115 volts These figures are for an average kit and will vary slightly for individual receivers CONTINUOUS BANDSPREADING Tuning is accomplished by means of two parallel condensers The band required is selected by the large cond...
Page 9: ... 1 Low Loss Valveholder Cat No 954 1 1 Low Loss Valveholder Cat No 964 1 3 1 Low Loss Valveholder Cat No 985 1 4 1 1 x 1 mfd Fixed Condenser 4 1 Aluminium Die Cast Chassis drilled all necessary holes finished inside and out battleship grey cellulose 12 9 1 Burr Walnut Bakelite Panel drilled neces sary holes 2 9 2 Bakelite Terminal Panels 6d 1 Scale and Pointer Knob 11 dial 1 1 Special 50 000 ohm V...
Page 10: ...components as shown in wiring plan and proceed to fasten them down It should be noted that the coil base and valve holder of V2 are mounted on insulating pillars When fixing variable condensers to panel take care to bed down squarely otherwise pointer may foul panel Make sure in the wiring that all joints arc strongly made One poor or high resistance joint can adversely affect the set s performanc...
Page 11: ...nser which is variable in ten equal steps only and is called the Tank Condenser A small vernier condenser slightly larger in capacity 20 m mfd than that of one step 14 m mfd in the tank condenser is used for final tuning Suppose the coils were tuned in the normal way with a 00016 mfd variable condenser The 6LB coil would tune from approximately 19 670 kc s at 0 on the dial to 10 067 kc s at 100 Th...
Page 12: ... of Tank Condenser 23 Moving Plates of Tank Condenser to No 4 Socket of Coil Holder 24 No 4 Socket of Coil Holder to F ncg of VI CONNECTIONS L S 9 YON 0 rr SWiTC11 25 No 1 Socket of Coil Holder to Fixed Plates of Tuning Condenser 26 H F Choke across Aerial and Earth Terminal 27 100 000 ohm Resistance Frcm No 6 Socket of Coil Holder to P of VI 28 One End of 1 mfd Condenser to P of V I Other End to ...
Page 13: ...s 1 3 point Switch I Ferranti AF4 Transformer 1 2 mfd Condenser 1 1 mfd Condenser 1 G B Battery 4 5 volts 1 G B Battery Clip Set of Leads 5 Plugs 2 Spade Terminals This set is not supplied as a complete kit but for reference the approximate cost of the parts is 83 6 less valves The following valves have been selected as most suitable for this set V 1 H F Position Mazda SG 215 11 V 2 Detector Mazda...
Page 14: ...ed lead in wires Figure 1 shows the detector input of a radio receiver during a period of short wave listening The set is being used in a densely populated area where the interference noise is high approximately 30 db above the noise level of the receiver A weak station giving 20 db input is therefore not heard in the speaker since it is 10 db below the level of the interference so Ipdftrr 44 To O...
Page 15: ...house In the case of the T aerial the down lead should be taken from the centre and soldered The best method of obtaining the down lead for the Inverted L aerial is to continue the horizontal portion by securely twisting it at the insulator and so avoiding the necessity of making a soldered joint 2 CROSSFEEDER DOUBLET AERIAL The Eddystone Crossfeeder Doublet is a static free large signal to noise ...
Page 16: ...d the aerial is directional receiving signals which are arriving parallel to the line joining the feeder and aerial in the direction nearest the matching resistance R Resistance R should be about 400 ohms and of the non inductive type A metallised composition resistance is perfectly satisfactory but should be enclosed in a glass tube or waterproof box since it will be exposed to all kinds of weath...
Page 17: ...r embodies an X41 triode heptode valve as frequency changer followed by two I F stages tuned to 465 K cs Then comes a double diode triode valve one diode for detection the other for automatic volume control The triode portion is used as a low frequency amplifier resistance capacity coupled into a steep slope pentode output valve The coils are easily interchangeable so that the receiver can be used...
Page 18: ... Works a slight re adjustment may be necessary owing to small variations in valves and circuit capacities This is done by tuning in a station at low volume and adjusting the sunken trimmer screws at the top of each I F trans former until the signal comes to maximum strength The following sequence should be used No 2 No 1 No 3 Greater ease and accuracy of trimming is obtained if a 465 K c oscillato...
Page 19: ...100 ohm I watt Resistors Erie or Dubilier 1 145 ohm watt Resistor Erie or Dubilier 3 200 ohm 1 watt Resistors Erie or Dubilier 1 1 000 ohm 1 watt Resistor Erie or Dubilier 3 10 000 ohm 1 watt Resistors Erie or Dubilier 1 15 000 ohm 1 watt Resistor Erie or Dubilier 1 30 000 ohm 1 watt Resistor Erie or Dubilier 1 40 000 ohm 1 watt Resistor Erie or Dubilier 4 50 000 ohm 1 watt Resistors Erie or Dubil...
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Page 21: ...AN B EDDYSTONE SHORT WAVE MANUAL 19 5 VALVE A C SHORT WAVE SUPER HETERODYNE RECEIVER a a 40µ ufd 500 000 10000 n 10 00041 30 00041 15 000 M 500 000 SL Under View of Chassis showing complete point to point Wiring ...
Page 22: ...teries etc and placing the oscillator alongside a receiver Tune receiver to a known station and by using in the oscillator a coil which is known to cover the wavelength of the station being received carefully rotate oscillator control knob until a high pitched note is heard superimposed on the trans mission being received This indicates the oscillator and transmitter to be in step Should the note ...
Page 23: ...ch amplifier is recommended a circuit diagram for this is provided The general circuit embodies three valves pentode Crystal Oscillator frequency Dolibler Pentode with control and screen grids tied together to function as triode and the final amplifier The three tray welded steel rack provides a solid foundation and the completed transmitter forms a neat and presentable instrument The power supply...
Page 24: ...heck entire tuning operation TELEPHONY OPERATION The output from speech amplifier can permanently be plugged into the jack on the extreme end of back terminal panel Telephony is obtained by depressing switch SW2 adjoining jack mentioned above This auto matically cuts out sending key and brings speech amplifier into circuit The amplifier must of course be switched on separately AERIAL LOAD In view ...
Page 25: ...u FILLCD 500V 12DM 2V 2A 20 H a 60 MA H T SuppLy FOR C O AND DOUBLER 2 soy Hrr 12 500v 120 4A NEATER SUPPLY FORALL TX VA LYES i V 3A CIRCUIT FOR POWER UNIT 250v 1 500 V 00 u u41 1 5w 1 250V 500 v TRANSMITTER CIRCUIT PCN4V B X X 145_1 10 000 n P40 PLv To BAC K OF Tx lopppPd Double Spaced 50 0 0 20 H 43016 8 1S1 500V ELEcreocmc RFC 494 Sw2 96v Pi 168v 6 8 BATTERY 4 ZO H SPEECH AMPLIFIER CIRCUIT IA g...
Page 26: ...dio knowledge is required For the absolute beginner the more simple Everyman Shortwaver is advised see pages 8 to 11 CONSTRUCTION The views of top and underside of chassis show layout of parts and the point to point wiring is easy to follow PROCEED TO BUILD AS FOLLOWS Scrape paint from chassis for all earth connections see wiring plan Fit valve holders and terminal strips by using 6BA screws and n...
Page 27: ... 115 1 The right hand knob is aerial trimmer and should be adjusted for maximum signals on each station The left hand knob regulates volume Switch on right side is local distance down for local up for distance The On off switch is on the left hand of the tuning dial The receiver is arranged for a doublet type of aerial Should it be desired to use with an ordinary aerial one of the sockets should b...
Page 28: ...ECEIVER continued LOCAL Din SWITCH 01 4 Orr SWITC CONTROL 111111111 0A 111 11111I1OrT 111111111V 111111 VIII MB TO FIXED PLATES OF TUNING COND BLACK E E 70 000 n 10 0001L 20 00o n O 0 0 0 40 000 BROWN BLACK ED LUE UNDER VIEW OF CHASSIS AND WIRING PLAN 5 MD 01 mFD ...
Page 29: ...egohm 1 watt Resistor Erie or Dubilier 1 3 point Switch 1 Microdenser 40 in mfd type 900 1 1 0 mfd Single Terminal Condenser Cat 4 3 1 2 point Switch 1 250 000 ohm potentiometer Erie No 989 2 r Black Knobs I hole Cat No 903 6d each 1 Aluminium Die cast Chassis drilled all necessary holes finished inside and out battleship grey cellulose Cat 3 0 1 0 5 ft 16 s w g Tinned Copper Wire 7 ft Slide back ...
Page 30: ...iles View of combined Transmitter and Receiver with handset ready for Duplex working These figures are based on actual ex perience greater ranges are sometimes obtained but they are not reliable This apparatus consists of two compact individual units the receiver and the trans mitter Either of these can be built and used separately The receiver is suitable for all ultra short wave reception and bo...
Page 31: ...nt of quench noise to zero and as the signal strength becomes weaker the quench noise is more pronounced It is of great advantage therefore in this type of receiver to have a minimum amount of quench noise so that the weaker signals can be received It is usual practice in quench receiver design to have the anodes of the detector and quench valves in parallel and to use a common H T supply Although...
Page 32: ... reaction the pre set condenser should be screwed well out Turn right hand control knob about one third on Screw pre set condenser down until receiver just oscillates Then check by turning knob anti clockwise when oscillation should cease By turning clockwise oscillation should take place again To check quench keep receiver oscillating and advance quench control knob until receiver stops oscillati...
Page 33: ...HE TRANSMITTER UNIT The transmitter unit consists of a push pull oscillator with a Class B modulator and a driver valve The first two valves are Osram type B21 and the driver valve is a Mazda P220 The advantage of a Class B modulator is that until modulated with speech it practically takes no high tension current but this rises when modulated to a maximum of 20 m a 0003 Fig 4 PRIM 1 000a of IOMA G...
Page 34: ...l THE AERIAL Most of the conventional types of ultra short wave aerials can be used with the transmitter as described These include the 2 wire matched impedance or the Zepp fed Hertz aerials the only necessity is to have a suitable coupling line between the output coupling coil and the aerial Full information about U S W aerials has already been pub lished in the Eddystone Ultra S W Guide The aeri...
Page 35: ...ll and there is a considerable saving in cost between the price of the two valves The frequency range which gives a com plete overlap each side of the 5 metre amateur band and the television wavebands is covered by a 40 m mfd condenser tuning a 5 turn silver plated coil A tapping from one side of the filament is taken to the centre of the coil The high frequency choke used in the filament lead mus...
Page 36: ...with associated coil and tuning condenser The wave length of 13 75 99 metres is covered by three interchangeable coils as follows Range 1 13 75 17 26 5 Range 2 25 0 51 8 Range 3 49 0 99 0 This method is highly efficient since there are no switch losses and the tuning capacity is small The circuit when the unit is used as a converter becomes an electron coupled os cillator and since a battery valve...
Page 37: ...the H F unit and then tune unit until it is in resonance with the main AERIAL TANK 4Turiai HF 0 EDDYSTONE PARTS Battery Model 1 Aluminium Die Cast Chassis drilled all Price necessary holes finished inside and out battleship grey cellulose Cat No 1059 12 9 1 Metal Panel finished Dark Crystalline Brown Cat No 1058 2 9 1 Bandspread Condenser Unit with Slow Motion Head Knob Dial and Cursor Cat No 1043...
Page 38: ...WIRING AND LAY OUT PLAN FOR ONE VALVE SHORT WAVE HIGH FREQUENCY AMPLIFIER 50000_n VARIABLE BATTERY MODEL To RECEIVER AERIAL TO RECE0 e13 EARTH RED BLACK 4 BLue BROWN 111111 l A A II II ...
Page 39: ...speaker or output valve of the main receiver TANK AERIAL 0 I 50 THEORETICAL EDDYSTONE PARTS A C Model Price 1 Tank Condenser with Knob and Graduated Dial Plate Cat No 1042 6 1 Bandspread Condenser Unit with Slow Motion Head Knob Dial and Cursor Cat No 1043 6 6 1 Screened H F Choke Cat No 982 5 1 Pointer Knob and Dial Cat No 1044 1 1 Base 6 pin Cat No 964 1 3 1 Valveholder 7 pin Cat No 985 1 4 1 Fi...
Page 40: ...g the soldering iron If electric supply is available an electric iron is of great advantage When once hot the current keeps it at a constant heat and it cannot overheat as an ordinary iron To prepare a new electric iron bit for soldering let the bit heat up dip into the paste flux and apply solder to the end of the bit until it is nicely tinned all over When soldering keep the end of the bit clean...
Page 41: ... BAND Top view of Transceiver showing oscillator vaAve tuning control and condenser and coils L2 sank L3 which are each 3 turns of 14g copper Wirei wound on a 1 1 corL The coils are atippbrt4d in the wiring except the aerial coupling centre whichlis fastened on the paxolin panel to the feed out terminals Most transceivers employ the squegging grid leak selfqnerich theft for reception but thii inod...
Page 42: ...10 600 25 000 ohms 3 meg 1 Cyldon 70 1 40 m mfd Capacitor 1 Igranic Jack 2 Belling Lee Plugs and Sockets 1 T C C M type Condenser 01 mfd 3 T C C M type Condenser s 002 mfd 1 Keston 25 4y 40 m a Choke No 204a 1 Keston Mic Transformer 100 1 No W44 1 On Off Switch 1 Utility Switch No W342 3 1 WB 5 pin Valveliolder The set is not supplied as a complete kit but for reference the approximate total cost ...
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Page 44: ... I PTION MAKER VALVE TYPE PIN NUMBER TOP CAP I t 4 i 6 7 Mains V M H F Pentode Mullard VP M G G3 H H C G A vP4B M A G H H C G G Battery V M H F Pentode Mazda VP2I0 M G G F F G2 A Mains H F Pentode Mullard SP4 MG G HHCG A Batter H F Pentode y Mazda SP2I0 M G C F F G A Mullard SP2 M G G 3 F F G A Mains Triode Hexode Freq C Battery Osram X41 A G G H H CAM A G X21 A Go C F F M A G Mains Double Diode T...
Page 45: ... 12 235 Reykjavik Iceland TF J 48 86 6140 Pittsburgh W8XK 00 00 SUN 19 40 20 00 06 00 19 84 15 121 Vatican City HVJ Daily 42 4 7074 Georgetown British Guiana 16 30 16 45 VP3MR 19 82 15 140 Daventry GSF 39 95 7510 Tokio Japan JVP TUES 19 76 15 180 Daventry GSO FRI 20 00 21 00 19 74 15 200 Zeesen DJB 14 00 17 30 38 48 7797 Radio Nations HBP SAT 18 30 08 00 23 30 00 15 19 72 15 210 Pittsburgh W8XK 14...
