Heathkit SB-220 Assembly And Operation Manual Download Page 74

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Summary of Contents for SB-220

Page 1: ...e buyers to believe it is his own production of the highest quality although it s our lowest He does this most often with free material he downloads from the Agilent web site but nothing is immune Please support original PDF producers leeches and marketers who obtain and sell the work of others and or sell free internet download material to naïve eBay buyers for high prices are directly responsibl...

Page 2: ...LINEAR AMPLIFIER MODEL SB 220 ...

Page 3: ......

Page 4: ...Assembly and Operation of the LINEAR AMPLIFIER MODEL SB 220 HEATH COMPANY BENTON HARBOR MICHIGAN 49022 ...

Page 5: ...ation 58 Knob Installation 59 TEST AND FINALASSEMBLY 61 INSTALLATION 65 OPERATION Controls Connectors And Meters 69 General 70 Tune up 71 Periodic Maintenance 74 IN CASE OF DIFFICULTY 75 Troubleshooting Chart 76 Factory Repair Service 77 Special Shipping Instructionsfor U S and Canada 78 SPECIFICATIONS 79 CIRCUIT DESCRIPTION PowerSupply 81 Relay 82 RF Circuits 83 ALC Circuit 83 Metering Circuits 8...

Page 6: ...ated by exciter relay contacts to place the Amplifier in the transmit mode The Amplifier can be operated from either 120VAC or 240 VAC 50 60 Hz lines and can be easily changed from one to the other Operation from a 240 volt line is recommended Each side of the line cord is equipped with acircuit breaker to protectagainstoverloads An important feature of this Amplifier is that it can be tuned up at...

Page 7: ...PARTS PICTORIAL B R O W N u continued on fold out from Page 7 ...

Page 8: ......

Page 9: ...ION No No Per Kit KEY PART PARTS DESCRIPTION No No Per Kit RESISTORS CAPACITORS 112 Watt 1 1 9 1 44 1 18 1 22 1 23 1 24 1 25 1 26 Other Resistors 2 1 8 1 1 38 1 1000S 2 brown black red 2200 S2 red red red 5600 S2 green blue red 22 k S 2 red red orange 27 kS2 red violet orange 33 k S 2 orange orange orange 47 kS2 yellow violet orange 100k S 2 brown black yellow 68 k S 2 1watt biuegray orange 4 7 M ...

Page 10: ...assembled in bag 39 73 4 1 5116 grommet 73 3 4 112 grommet 73 2 1 314 grommet 40 75 123 1 Line cord strain relief 75 124 1 6 x 4 112 fish paper insulator 41 75 125 8 Capacitor mounting insulator 42 255 39 1 6 32 x 1 114 tapped phenolic spacer 43 255 42 3 6 32 x 314 tapped phenolic spacer 44 431 14 1 2 lug terminal strip 45 431 10 3 3 lug terminal strip 46 43142 1 5 lugterminal strip 47 431 20 1 6 ...

Page 11: ...8 screw 832 nut 8 lockwasher 8 32 x 1 318 spacer 8 solder lug 10 24x 1 round head screw 10 24riut 10 24wing nut 10 lockwasher Cable damp 440 x 5 16 screw 440 nut Control nut Speednut Control flat washer 112 flat washer 314 flat washer Control lockwasher 5 lockwasher 10 double lug KEY PART PARTS DESCRIPTION No No Per Kit Other Hardware cont d 95 258 115 1 Brassspring 518 x 5112 96 25410 1 Control s...

Page 12: ...PARTS PICTORIAL cont d ...

Page 13: ...Page 8 p r e b l g ...

Page 14: ...me to sethe actual positions of wires and components Lockwashers and nuts will be used with most screws when mounting parts unless the assembly steps state otherwise Consequently the applicable stepswill call out only the size and type of hardware used For example the phrase Use 6 32x 114 hardware means to use 6 32x 114 screws one or more 6 lockwashers and 6 32 nuts Refer to the Details for the pr...

Page 15: ...OTE D I O D E S M A Y BE S U P P L I E D I N A N Y OF THE F O L L O W I N G SHAPES THE CATHODE E N D OF THE D I O D E I S M A R K E D W l T H A B A N D OR 2 A N D S A L W A Y S P O S I T I O N T H I S END A S S H O W N I N THE P I C T O R I A L y o s i t i o n the circuit board a s shown and install diodes 57 27 at D7 D5 D3 Dl D9 D11 and D13 Make sure all seven cath ode banded ends a r e to the So...

Page 16: ...ack hookupwire to hole B on the circuit board 6 1 Preparethe following lengthsof hookupwire L 5 11 4 red 3 314 black 6 112 black 17 112 small black strandedwire 7 112 orange 6 112 yellow 9 112 heavy blue thick insulation I 2 314 heavy blue thick insulation Connect a 6 112 length of black hookupwire to hole Con the circuit board S 11 f1 Connect a 17 112 length of black stranded wire to hole E on th...

Page 17: ...completes the prewiring of the circuit board Set it aside until called for later Proceed with the Input Coil Assembly section INPUT COIL ASSEMBLY Refer to Pictorial2 1 for the following steps Refer to Detail 2 1A for the next two steps NOTE A plastic nut starter has been providedwith this kit Use it to hold and start nuts on screws See Page 3 of the Kit BuildersGuide for more information PICTORIAL...

Page 18: ...mounting ears snap out to holdthe coil in placeas shown in Detail 2 1C Detail2 1B d lnstall the 2ameter mil 40965 at CV See Detail 2 1C Installthree 6 solder lugson the coil mountingshield 4 Installa 10115 metercoil 40 964 at CX 206 457 at CL with 6 32x 318 hardware Position the lugsas shown in Detail2 10 4 Installa 10115 metermil 40 964 at CY d Installthe 8 h e t e r coil 40 1012 at CS dInstall a...

Page 19: ... lug CL 3 NS d Connect a 115 pF mica capacitor from lug 1 of coil CY NS to ground lug CL 2 NS 4 Refer to the inset drawing on Detail 2 ID and twist together the leads of t w o 22 pF mica capacitors a s shown NOTE Each twisted pair of leads will be counteda s leads in asolder step I t j Connect one pair of leads to lug 2 of coil CY NS and the other pair of leadsto ground lug CL 3 NS Note the positi...

Page 20: ...0 pF and a 680 pF mica capacitor together Connect one pair of leads to lug 2 of coil CS NS and the other pair of leads to ground lug CL 1 6 5 y Connect a 470 pF mica capacitor from lug 1 of coil CT NS to ground lug CL 3 S 4 Position the capacitor as shown PICTORIAL 2 1 Repeat d Turn the shaft of the bposition rotary switch 63 561 fully clockwise as viewed from the shaft end J Refer to Detail 2 IFa...

Page 21: ...switch lug at the same position it will count asthreewires 6 3 in the solder instructions 2 114 Connect the prepared hookup wires from the coils to wafer 1 of switch CZ as follows Connect to Wire Connect From Wafer 1of Length Lug 1of Switch CZ IV 2 1 4 Coil cu s 2 Lug 4 6 31 4 3 112 Coil CT S 2 Lug 5 S 31 43 112 Coil CS 6 31 Lug 6 6 31 NOTE Switch CZ has lugsonly on the front of the wafer at posit...

Page 22: ...ows Prepare the following lengths of black hookup wire Connect to Wires are listed in the order in which they will be used Wire Connect From Wafer 1of Length Lug 2 of Switch CZ 2 112 04 2 112 Coil CY 6 3 Lug 8 S 3 2 142 Coil CX 6 21 Lug 9 6 3 I dd 2 1ns8 Coil cu6 2 u g 10 6 31 i 4 2 lnl1 Coil CT 6 2 L U 11 s 3 2 112 t A 2 1 Coil 2 36 3 Lug 12 6 3 ...

Page 23: ... THE INNER I N S U L A T I O N AND STRETCH OUT to solder lug DF NS THE S H I E L D A P P L Y A S M A L L AMOUNT OF SOLDER TO THE END OF THE SHIELD AND THE INNER L E A D U S E I cut each lead of a 500 volt smailer OOI IF disc ONLY ENOUGH HEAT FOR THE SOLDER TO FLOW capacitor to a length of 314 Connect one lead of this capacitor to lug 7 of wafer 1 of switch CZ 6 2 The SOLDER other lead will be conn...

Page 24: ...H A F T END Detail 2 66 Refer to Detail 2 68 for the following steps I fStan two 6 32 x 3 16 screws into the tapped holesof the shaft coupler 456 16 Then slide half the length of the shaft coupler onto the shaft of switch CZ and tighten one screw The screws should be at the one o clock position viewedfrom the shaft end CAUTION Be careful when you tighten the setscrew in the ftdlo ing step Use an a...

Page 25: ...tail 3 1A INSET P U S H O N C O N T R O L N U T C O N T R O L FLAT W A S H E R Detail 3 1B J dRefer to Detail 3 16 and install the 3 position rotary switch 63 47 at EU Use a control lockwasher a control flat washer and a control nut Position the switch lugs as shown in the Pictorial 4Refer to Detail 3 1C and install the 100 k 2 sensitivity control lo 12 at ET Use a control solder lug a control fla...

Page 26: ...r to Detail 3 ID and install the plate meter 407 145 at EA Use the hardware supplied with the meter Install a 3 lug terminal strip at EB Note the lockwashers used CAUTION Do not overtighten the meter hardware as the meter case can be damaged i dl Refer to Detail 3 1E and install the multi meter 407 146 at EC Use the hardware supplied with the 4 Remove and discard the wire jumpers between the meter...

Page 27: ... Cut the leads of two 02 pF disc capacitorsto a length of 112 These capacitors will be used in the next two steps Connect the black pilot lamp lead coming from meter ECto lug 1of terminal strip EB NS 4Connect the white pilot lamp lead coming from meter EC to lug 3 of terminal strip EB NS Ih u t the black pilot lamp lead coming from meter EA to 3 and the white lead to 4 j Connect the black pilot la...

Page 28: ...B 6 4 dConnect an 18 length of brown wire to lug 1 of terminal strip EB 6 4 4 Connect a 30 length of green wire to lug 3 of control ET S I dRemove an additional ID of insulation from one end r r Gather the green wire and the two brown wires and of the 3 112 black wire Pass this end through lug 1 twist them together approximately one turn per inch of control ET 6 21and wrap it around the control so...

Page 29: ...ilarly mount a DPDT rocker switch 61 15 at on the rear apron AN on the chassisfront apron 4 Refer to Detail 4 1B and mount a phono socket a t u NOTE Discard any loose metal clips you ind in the tube on the rear apron Use 6 32x 114 hardware Position sockyt boxes the ground lugtoward the coaxial jack Refer to Detail 4 ID and mount a 5 lug ceramic tube 6 3 2 x 114 dsocket at N with a 2 lugterminal st...

Page 30: ... D E R L U G 8 6 3 2 x 114 S C R E W Detail 4 1F Refer to Detail 4 IF and mount a 3 lug terminal strip at P Use 6 32 x 114 hardware Refer to Detail 4 1G and mount a long solder lug at R Use 6 32 x 114 hardware 6 L O C K W A S H E R L O N G S O L D E R LUG 0 6 3 2 x 1 4 r S C R E W Detail 4 1E Detail 4 1G ...

Page 31: ...sition the relay with its lugs to the left Unsolder and discard the black insulatedwire between lug 9 and the movable arm Replace the wire discarded in the previousstep with a 4 length of small metal braid that is folded in the middle and pushed through a 1 318 length of black sleeving Solder one end of the braid to lug 9 and the other end to the movablearm Refer to Detail 4 1K and mount the relay...

Page 32: ...acitor from lug6 of terminal strip BE NS to solder lug BF S 3 Refer to Part Bof the Pictorialfor the next eight steps J Prepare a 10 lengthof orangehookupwire and a 17 length of yellow hookupwire dConnect one end of the orange wire to lug 6 of terminal strip BE NS 4 Connect one end of the yellow wire to lug 2 of terminal strip BE S 2 1 Pass the free ends of the yellow and the orange wires down thr...

Page 33: ...K F PICTORIAL 4 1 w rC 0 0 n 0 e 3 LUG 0 0 0 0 0 0 0 0 0 ...

Page 34: ...PICTORIAL 4 5 ...

Page 35: ... R A S S S P R I N G J 6 LOCKWASHER 6 32 N U T SOLDER LUG 4 Refer to Detail 4 38 and mount the brass spring 258 115 at CD and CE on the RF shield Use6 32 x 318 flat head hardware with a 6 solder lug at CE When the hardware is tightened the end of the brass stripwill contactthe upper lip of the RF shield Refer to Detail 43C and cut one lead of a 500 pF mica capacitor may be marked 0005 to a length ...

Page 36: ... MMFD Use a 6 32 x 1 4 flat head screw with a 8 lockwasher between the capacitor and the RF shield STEEL A Install a 6 solder lug on the other terminal of the capacitor with a 6 32 x 3 16 screw Position the solder lug as shown 1 0 3 2 NUT a J Refer to Detail 43E and install the zener diode at C W on the outside of the RF shield with the mounting stud and nut on the same side of the shield as the b...

Page 37: ...Page 30 6 SOLDER LUG 6 x 318 SHEET M E T A L SCREW SHEET M E T A L PICTORIAL 4 4 S H I E L D r l ...

Page 38: ...il 4 5B for the next two steps tfl From the bottom of the chassis install 6 sheet metal 4 Install two 1 118 tapped spacers on the 80120 plate screws at CH and CJ into the coil mountingshield coil 40 597 Use 6 32 x 114 binder head screws contactany part on switch CZ 4Make sure none of the pm on terminal mip BE Mount the plate coil as mbly at CB and CC on me inside of the RF shield Be sure to positi...

Page 39: ...e it is soldered in place The end of each wire going through the switch lugs must first be flattened as shown in the inset drawing of Detail 4 5E DO NOT use the switch lugs to hold one end of the wire when forming it as the switch lugs and the ceramic switch wafer can be damaged Detail 4 5E When soldering wires to the switch make sure the wire is Refer to Detail4 5 and connect barewires from wafer...

Page 40: ... B R A C K E T and a 6 32 nut on the third made bolt Bendthe two indicated solder lugs straight down before installing the capacitor Refer to Detail 4 5G and mount variable capacitor 26 131 at holes BA Use6 32x 318 hardwareand 314 flat washers Refer to Detail 4 5H and install the platecoil bracket 204 1042 on the rear of variable capacitor BA Use the two extra nuts and lockwashers supplied with th...

Page 41: ...l butt snugly against it AConnect the tab on the coil to hole DA in the plate coil bracket Use 6 32 x 114 hardware 1 Solder the coil tubing and the wire lead from the switch wafer to lug 1 of the 80120 plate coil Make sure the end of the tubing is against the solder lug and that this connection is well soldered f1 Connect the free end of the silver plated strip to lug 2 of wafer 2 of switch CZ Fle...

Page 42: ...htenthe screw as the threads in the ceramic choke form can be damaged Position the choke so solder lug DC pointstoward spacer DD Refer to the Pictorial for the next two steps Install a 6 solder lug on one end of a 001 uF capacitor 21 165 Usea 6 32x 3116 screw d Connect a 1 112 bare wire from the solder lug on capacitor CM S I to RF choke solder lug DC NS J I Mount this capacitor at DB on the plate...

Page 43: ...PICTORIAL 4 6 ...

Page 44: ...Make sure the fish paper clears the zener diode and the sheet metal screw at CG Rubthe paper firmly into place d Refer to Detail 4 68 and mount the filament and bias transformer 54 238 on the top of the chassis As you position the transformer insert the two large green leads and the green yellow lead down through 1 grommet AH Insert the other leadsthrough grommet 1 AK Use 8 32 x 318 hardwareat AJ ...

Page 45: ...ount the front panel Replace the control flat washer and the control nut on assembly on the front of the chassis Insertthe twisted switch CZ hookup wires two brown and one green down through grommet AL Use 6 32 x 318 phillips head hardwareat EH and EJ ...

Page 46: ...ce 1 Adjust the position of the filament and bias Refer to Detail 4 6D and install the left side panel 203 6461 Use 6 32 x 318 phillipshardwareat EF between the transformer end bell and any connections Use 6 x 318 sheet metal screws at EJ EK EL EN to the lugsof switch EU EP and ER ...

Page 47: ... the red and the against the rear panel check the two offcenter holes redlyellow leads down through grommet Y Use an FK and FJ which if viewed a s shown in the Detail 8 32 x 318 screw a 112 flat washer a 8 solder lug must beclosest to the bottom left handcomer and an 8 32 nut at AD At BX BY and BZ use 8 32x 318 hardware with a 112 flat washer at each ldcaion Before you tighten the hardware make su...

Page 48: ... t I I 4 Rkfer to Detail 4 6H and installthe fan blade assembly 266 296 on the fan motor shaft Position the fan m m r and the blade assembly as shown and apply I I firm downward pressurewith both thumbs on the fan I I blade hub A slight rocking motion will help Push the 1 I fan blades onto the motor shaft until there is 1 16 to I I 1 32 clearance between the fan blade hub and the motor frame I I I...

Page 49: ... 32 x 318 flat head screws Note that the diodes and the phenolic spacers are along the lower edge of L l the circuit board Refer to Detail 4 78 and mount the capacitor bank bracket with one spade bolt enteringeach of holes BR BS BT and BU Use 6 lockwashers and 6 32 nuts only on spade bolts BR BS and BU Leave the nuts flush with the ends of the spade bolts Mount a 5 lugterminal strip 431 42 on spad...

Page 50: ...ion into the vacated space in the bracket Part D Align the capacitor lugs and the polarity markings as shown Then push the capacitors snugly against the fish paper and tighten the spade bolt nuts on the bottom of the chassis just to the point where you can no longer rotate the capacitors with your fingers Do not overtighten Note the position of the terminal strip mountingfoot in Detail 4 7B Detail...

Page 51: ...nt end of one of the 1 518 bare wires t o the negative lug of capacitor 3 NS and the straight end t o the positive lug o f capacitor 4 NS J Place a 314 length of slewing on one lead of a 30 kS2 resistor and connect this lead t o the negative lug of capacitor 3 S 2 Connect the other lead t o the negative lug of capacitor 4 S 2 Place a 314 length of sleeving on one lead of a 30 kS2 resistor and conn...

Page 52: ... f PICTORIAL 4 7 ...

Page 53: ... lead of a 001 eF 6 kV capacitor through J Black C solder lug CF 6 21 to hole K in the circuit board J Red S 1 Connect the other lead of this capacitor to A Lug2 of plate meter S 2 Lug 1of plate meter 6 2 solder lug CK NS 4 Insert the black stranded wire coming from hole E in the circuit boarddown through grommet AL 4 Peel off the backing paper from the DANGER label and press it into place on the ...

Page 54: ... M J Page 45 H I G H VOLTAGE DANGER I C A P A C I T O R B R A C K E T PICTORIAL 4 8 ...

Page 55: ...n 5 314 J1 At grommet AK cut the transformer leadsas follows One red 4 112 Other red 4 Black Red 3 314 Black Yellow 3 314 Black 3 112 Black Green Do not cut i i1 NOTE When you remove insulationfrom transformer leads I in the following steps grasp the wires where they emerge from the chassis so no strain will be placed on the connectionsat the transformer end of the leads PICTORIAL 4 9 Remove 114 o...

Page 56: ...CER 6 Connect a 02 pF disc capacitor from lug 1 NSIto lug 2 NS of terminal strip P Connect a 02 uF disc capacitor from lug 3 NS to lug 2 S 2 of terminal strip P Connect the green wire from grommet AL to lug 1 of terminal strip B NS Detail 48B Connect the transformer leadsfrom grommet AK as follows NOTE Before starting the wiring in the following steps look ahead to the under chassis photograph on ...

Page 57: ...eceding step onto lug 3 of switch Z Connect the other end of this wire to double lug AW NS Connect the black lead from grommet AK to double lug AW NS f I Connect the black lead from grommet Y to double lug AW NS p r e m e n g h I f stranded wire Place 1 len htaf larkdea s evhg on orle end of this wire In all a s all connector tab 32 6 on end of the wireb h tt Ic eevid on c T n ush the L h l f w a ...

Page 58: ...rip BT other 13 112 wire onto lug2 4Connect the black stranded wire coming from J Prepare a 12 112 length of black strandedwire grommet AL to lug 5 of relay F S 1 4 Connect a 3 red hookup wire from lug 2 NS to lug J 11 S 1 of the relay Connect the free end of the black yellowwire coming from grommet AK and one end of the 12 112 wire in VJ Connect a 9 112 length of red hookup wire from lug the prec...

Page 59: ... PICTORIAL 4 10 ...

Page 60: ...PICTORIAL 4 11 ...

Page 61: ...W PICTORIAL 4 13 ...

Page 62: ......

Page 63: ...lug M2 S 2 4 Connect a 02 uF disc capacitor from lug 1 NS to lug 2 NS of terminal strip B 4 Connect one lead of a 1000 G brown black red resistor to lug 2 6 2 and the other lead to lug 3 NS of terminal strip B J Connect the cathode banded end of a germanium diode brownwhitebrown to lug 1 6 3 and the other lead to lug 3 NS of terminal strip 6 4 Connect one lead of a 68 kS2 blue gray orange 1watt re...

Page 64: ... is first removed from end A and that the center conductor and inner insulation are then cut U Detail4 12E END A d Refer to Detail 4 1 2E and form and fit a 5 314 length of silver plated strip as shown The hooks in the ends of the strip should be of a size to fit around the bare wires at S ahd J in the Pictorial I As shown in Detail 4 12F fit the silver plated strip onto the bare wires Fit the loo...

Page 65: ...ug8 6 21 and the 1 lead to lug 2 6 31 of relay F as shownin inset drawing 2 of the Pictorial Refer to Pictorial 4 13 Wd out from Page 501 for the following steps Refer to Detail4 13A for the followingthree steps d l Remove a knurled nut from each of the two circuit breakers 65281 A H E X G O N A L NUT F BREAKER Detail4 13A 4Position the face of each hexagonal nut 114 from the end of the mountingbu...

Page 66: ...ain relief on the terminal strip AE S 1 to lug 2 of circuit breaker AA line cord just beyond the split portion of the cord as NS shown Use a pair of gas pliers to compress the strain relief and then insert it into hole AC from the outside I Connect a O1 pF 1 4 kV disc capacitor from solder of the chassis lug AD NS to lug 2 of circuit breaker AB NS 4Connect a O1 pF 1 4 kV disc capacitor from solder...

Page 67: ...er the green lead to the wire loop and the wire loop to the solder lug but be to keep the other wire loopfree of solder Also solder the lead from the 02 uF disc capacitor and the brown wire to lug 1at this time the preceding step at lug 3 of terminal strip P for the 5 314 green lead Detail4 13F M Refer to Detail 4 13F and form two 1 112 lengthsof bare wire Then fit one wire from lug 1 of tube sock...

Page 68: ...etail 4 148 and pass a cable tie 354 5 around all of the wires a t each of the six points shown in the Pictorial to form a neat cable Equalize any slack in each wire between the ends of the wire Then pull each cable tie snug and clip off the excess length of the tie 120 240VOLT WIRING This amplifier can be operated from 120or 240 volts 50160 hertz alternatingcurrent Make the proper connections on ...

Page 69: ...y PICTORIAL 4 14 ...

Page 70: ...I2 x S C R PICTORIAL 4 20 ...

Page 71: ...teps 1 Install a 6 solder lug on the top end of each plate connector 260 12 Use a 6 32 x 3 16 screw but leave it loose Start a 6 32 x 3 16 screw into the side of each plate connector 41 Place each plate connector on the plate cap of a final tube 3 5002 and tighten the screw on the side of 6 3 2 3 1 6 S C R E W C O N N E C T O R each connector i 1 1 Place a final tube in each tube socket Detail 4 1...

Page 72: ...ke at DK S 3 Push the other end over the solder lugon the capacitor at DN S I Detail 4 15B NOTE When you install parasitic chokes in the following steps center the chokes betweenthe solder lugs Y P E N C l S M A L L L O R k J Cut each lead of the two parasiticchokes 45 53 to S C R E W D R I V E R a lengthof 718 tJ Refer to Detail 415B and install a parasitic choke from solder lug DJ S 1 to solder ...

Page 73: ...our exciter Refer to Pictorial 4 16 or Pictorial 4 17 as appropriate I P R E P A R E ONE END A S SHOWN I T A K I N G C A R E NOT TO N I C K THE OUTER S H I E L D OF W I R E S R E M O V E THE OUTER I N S U L A T I O N I P U S H THE S H I E L D B A C K A S F A R A S I T W I L L GO A N D R E M O V E THE S P E C I F I E D LENGTH OF I N S U L A T I O N F R O M THE I N N E R LEAD I P L A C E THE P H O N...

Page 74: ...crews into each of the three large knobs Start a single setscrew into each of the two small knobs 1 Turn the shafts of the Tune and Load capacitors so the platesof each are fully meshed 1 Turn the three other shafts fully counterclockwise 1 Install the knobs on the shafts so the index marksare positioned as shown in the Pictorial and tighten the setscrews S M A L L LARGE Detail 4 18A Proceedto Tes...

Page 75: ......

Page 76: ...oot between the brass spring and the metal spacer If you fail to do this the high voltage circuit will be short circuited you will be unable to obtain a plate connector resistance reading and damage will result if power is applied J The resistance between the plate connectors and the chassis should measure approximately 200 k51 after the meter stabilizes The resistance between lug 3 of each tube s...

Page 77: ...pringwhich protrudesbeyondthe metal spacer NOTE If at any time during the testing and operation the Linear Amplifier does not perform as described unplugthe d Refer to Detail 4 198 and install a 6 32 X 1 114 Linear Amplifier linecord and refer to the In Case of tapped phenolic spacer 255 39 on the underside of i f f i l section of the n lanual the perforated cover at the marked hole Usea 6 32 x 31...

Page 78: ...ximately 3000volts TESTS J 1 Pushthe POWER switch to ON NOTE There should be no indicationon either panel meter except when the METER SWITCH is at the HV position Check to see that the tube filaments and meter pilot lamps light and that the fan operates The right hand Push the POWER switch to OFF and unplug the line meter should read approximately 2500 volts cord ...

Page 79: ...have the amplifier cabinet sit level install a rubber foot at each corner of the cabinet Use 6 32 x 11116 screws If you wish the front of the cabinet to be elevated install a rubber foot on each rear corner with 6 32 x 11 16 screws Then install a tapered spacer and a rubber foot at each front corner of the cabinet with 6 32x 1 112 screws NOTE The blue and white identification label shows the Model...

Page 80: ...aving 10gauge conductorsand 20 ampere fuses DO NOT use this Amplifier at its full ratings on a regular house wiring circuit as the ratings of the wire will almost certainly be exceeded Avoid excessively long runs of wire from your service entrance A heavy flow of current in such a line resultsin a voltage drop which can affect the performance of your equipment If you use a power cord plug that is ...

Page 81: ...n is not available this function must be provided by other means If a separate coaxial send receive relay is used in your station it may have external contacts available A separate switch can also be used HEATHTRANSCEIVERSWITH 11 PINPOWER PLUGS If you will use your Amplifier w h a Heath transceiver which has an 11 pin power plug on the rear panel refer to Pictorial 5 and perform the following step...

Page 82: ...Page 67 I R F H P S E R I E S A LC S B 1 0 1 T R A N S C E I V E R O U T P O W E R S U P P L Y RELAY ALC Figure 2 1 C A P P O W E R C A B L E PICTORIAL 5 ...

Page 83: ...H W 1 0 0 T R A N S C E I V E R ANTENNA FIGURE 2 2 8 0 4 0 OR 20 METER S I N G L E B A N D T R A N S C E I V E R H P S E R I E S POWER S U P P L Y 5 8 2 2 0 A M P L I F I E R FIGURE 2 4 ...

Page 84: ...FIGURE 2 3 C O A X I A L A N T E N N A RE LAY r f 1 TO R E C E I V E R C O A X I A L R E L A Y E X T E R N A L C O N T A C T S FIGURE 2 5 ...

Page 85: ...Shows plate current to Shows hlgh voltage In kV g r d current In mA 2 K W L I N E A R A M P L I F I E R ON CW TUNE I 1 FIGURE 3 1 I iI I 11 II I I ANT RELAY ALC RF INPUT RF OUTPUT I I Figure 3 2 ...

Page 86: ...Page 68 ...

Page 87: ...1ampere Notethat by adding the proper number of zeros and dropping the decimal point each scale number may be read as milliamperes Thus 5 amperes would become 500 milliamperes Multi Meter Read the Multi Meter scale which correspondsto the setting of the METER SWITCH PLATE VOLTAGE K V Figure3 3 SCALE READING 0 350milliamperes lower scale 0 350 lower scale Adjust needlede flection to full scale with...

Page 88: ...pproximately 100 watts of RF output An exciter of lower power output may be used a s a driver but the Amplifier s output will be less If you use an exciter that deliversmore than 100 watts carefully adjust the driving power to avoid overdrive and the creation of spurious signals which create needless interference to others The use of the Heathkit Model 610 Monitor Scope is highly recommended for c...

Page 89: ...owing procedure for tuning the Amplifier should a s the Heathkit Cantenna or an appropriate antenna take only a few seconds after you go through it afew times connectedto the Amplifier output Note the LOAD control position so it can be preset the next time a particularband is used Set the Amplifier controlsas follows SWITCH OR CONTROL TUNE I LOAD BAND SENSITIVITY METER POWER CWITUNE POSITION Desir...

Page 90: ...onal trapezoid display pattern is more easily interpreted for voice patterns CAUTION While actually transmitting DO NOT switch betweenCW TUNEand SSB modes SSB PROCEDURE Jl Tune up the exciter and Amplifier as for C W operation NOTE Inthe absenceof the recommended oscilloscope monitor either the PLATE METER or the REL PWR indication can be used to monitor SSB transmission The PLATE METER indication...

Page 91: ...harp indicating a clean signal and they will attain a height greater than the single tone pattern of Figure 3 5 indicating maximum power input Figure3 6 Oscilloscope pattern and plate meter reeding 5 a resulting from overdrive The meter reads higher but the scope indicates peak PLATE AMPERES flattening Operation in this manner causes distortion and severe interference to adjacent frequencies Figur...

Page 92: ...over of the Amplifier and remove the dust While the top cwer is removed add onedrop of light at least once a year This can be done by using the blower machineoil to each fan bearing connection on a vacuum cleaner or by a soft bristle brush ...

Page 93: ... wired into the circuit as shown in the 2 The majority of the kits that are returned for repair Pictorial Diagrams and as called out in the wiring do not function properly due to poor connectionsand instructions soldering Many troubles can be eliminated by carefully reheating all connections to make sure that 5 Check for bits of solder wire ends or other foreign they are soldered as described in t...

Page 94: ...AUSE A Circuit breakersopen B Jumpers missingon terminal strip AE C Terminal strip AE wired wrong A Resistor R1 R3 B D17 R25 R24 C54 R26 C R6 R7 R8 R9 D Meter switch A Meter jumper wire not removed B R2 C3 C8 C Meter switch A ZD1 A Relay B ZDI C v 1 v2 A D l D14 B C10 C17 C R12 R19 D TI E R1 or R3 F C29 G Top cover off interlock A D16 B a C Ant Relay jack D T2 E RL 1 A Bandswitchwafer 2 180degrees...

Page 95: ...nal invoiceor sales slip it will be returned to you If it is not convenient to deliver your kit to a Heathkit Electronic Center please ship it to the factory at Benton Harbor Michigan and observe the following shipping instructions A brief descriptionof the difficulty The invoice or sales slip or acopy of either Your authorization to ship the repaired unit back to you C O D for the service and shi...

Page 96: ... is packed in the Model 220 Service Pack Due to the weight The deposit for the Service Pack will be credited against any of the transformers shipment without special packagingwill service charges or will be refunded asapplicable almost certainly result in damage Order a 171 3167 Model SB 220 Service Pack from the OVERSEAS SHIPMENT NOTE Shipment from overseas Heath Company Benton Harbor Michigan 49...

Page 97: ...00watts RTTY 1000watts SSB continuousvoice modulation CW Continuous maximum key down 10 minutes RTTY 50 maximumtransmit time 10 minutes C 30dB or better 52 51unbalanced 5052unbalanced SWR 2 l or less Tune Load Bandswitch Sensitivity Meter switch Power CW Tune SSB Platemeter Multi meter Grid mA RelativePower and High Voltage Linecord Circuit breakers two 10 A Antenna Relay phono ALC phono RF lnput ...

Page 98: ...0160 Hz at 10 amperesmaximum Cabinet Size 14 718 wide 8 114 high 14 112 deep NetWeight 50 Ibs The Heath Company reserves the right to discontinue instruments and to change specifications at any time without incurringany obligationto incorporate new features in instrumentspreviouslysold ...

Page 99: ... The red yellow transformer lead is connected to the C2 junction of capacitors C13 and C14 During the half cycle when this lead is positive capacitors C14 through C17 are charged During the other half cycle the red lead is positive and capacitors C10 through C13 are charged These two capacitor strings are in series across the load and the HIGH VOLTAGE SUPPLY voltagesof each group add together The ...

Page 100: ...ransmit mode the center tapof the filamentwinding is connectedto ground through lugs 8 and 5 of the relay the 5 1 volt zener diode ZDI and R3 The plate current through the zener develops 5 1 VDC operating biasfor the tubes and limits the idling platecurrent RELAY The relay has three sets of singlepole double throw contacts When the relay coil circuit isopen the contactsare inthe receivemode Approx...

Page 101: ...C55 loading capacitors C56and C57 and coils L6 and L7 Band switch wafer 2 progressively shorts out the unused portions of coils L6 and L7 The coil turns in useare tuned to resonance by Tune capacitor C55 Load capacitor C57 is tuned to completethe impedance match between the tubes and the load connected to the RF OUTPUT On the 80 meter band fixed capacitor C56 is switched in parallelwith C57 to pro...

Page 102: ...ensitivity control R26 to the Multi Meter The Sensitivity control adjuststhe Multi Meter for the desired reading To read grid current the Multi Meter is switched in parallel HighVoltage Figure4 4 with shunt resistor R3 The grid circuit return is to the center tap of the filament winding of transformer T2 Note Highvoltage is measured by switchingthe Multi Meter to the that grid current only passes ...

Page 103: ...CIRCUIT BOARD X RAY VIEW VIEWED FROM FOIL SIDE ...

Page 104: ...C H A S S I S PHOTOGRAPHS M O D E POWER SWITCH SWITCH ...

Page 105: ...Page 87 ...

Page 106: ... T H A N 1 ARE I N pF VALUES OF 1 AND ABOVE ARE I N pF UNLESS M A R K E D OTHERWISE 3 THE B A N D S W I T C H I S I N THE 8 0 METER P O S I T I O N ARROWS I N D I C A T E THE D I R E C T I O N OF R O T A T I O N FOR THE VIEW SHOWN 4 T H I S S Y M B O L I N D I C A T E S A CONNECTION TO C I R C U I T BOARD GROUND F O I L A THIS SYMBOL INDICATES A CONNECTION TO THE CIRCUIT BOARD 120 V I C CONNECTION...

Page 107: ...Page 88 MULTI METER PLATE METER METER SENSlTlVllTY C24 C25 SWITCH CONTROL EU ET ...

Page 108: ...c J i j Page 89 40 1012 40 965 40 964 LUG 1 ...

Page 109: ...r Form is not available refer to are available from your local Heathkit source and will reflect Replacement Parts in the Kit Builders Guide PART PRICE Each No RESISTORS 112Watt 1 9 1 44 1 18 1 22 1 23 1 24 1 25 1 26 Other Resistors 1 8 1 10 1 38 1 10 3 1 2 25 68kS2 1 watt 4 7 MS2 1 watt 82S2wire wound 2watt same size as 1 watt 5 1 S2wire wound 5watt 1 3600S2wire wound 5watt 1 30 k S 2film 7watt PA...

Page 110: ...245 34 00 3 5002tube PART PRICE DESCRIPTION No Each INSULATORS GROMMETS TERMINAL STRIPS CONNECTORS Ceramic feedthrough insulator 5116 grommet 112 grommet 314 grommet Linecord strain relief 6 x 4 112 fish paper insulator Capacitor mounting insulator 6 32x 1 114 tapped phenolic spacer 6 32x 314 tapped phenolic spacer 2 lugterminal strip 3 lugterminal strip 5 lugterminal strip 6 lugterminal strip 4 s...

Page 111: ...crew 8 32x 318 screw 8 32nut 8 lockwasher 8 32x 1 318 spacer 8 solder lug 10 24x 1 round head screw 10 24nut 10 24 wing nut I0 lockwasher 4 40x 5 16 screw 4 40nut Control nut Speednut Control flat washer 112 flat washer 314 flat washer Control lockwasher 5 lockwasher 10 double lug PART PRICE DESCRIPTION No Each Other Hardware cont d 258 1 15 25 Brass spring 5 1 8 x 3 112 259 10 05 Control solder l...

Page 112: ......

Page 113: ......

Page 114: ...onnections for the surge protection circuit matic with a standard relay coil and a current limiting resistor Therefore the high cost plus purchase time and final alteration of a time delay relay can be avoided The mods I ve installed are not unfamiliar as they ve appeared in several 1970 series of the Radio Amateur s Handbook However I ve described the procedures in a detailed order using short so...

Page 115: ...from the componentside Next a Solder each padwith its three wires b Clipcomponent pigtailsas you go c Clean boardto removeflux d Ohmmetercheck note highswill be 470 k 9 Connect board to SB 220 using the following sequence a Solder redwire to hole D b Solder bluewires at holes Hand J c Mount board using three screws omit lower LH d Solder barewire at hole K e Solder blackwire at hole E f Solder bla...

Page 116: ... few seconds of dead silence This delay time is controlled by the value of the limit ing resistors During this period the plate voltage meter can be observed to slowly increase from zero to about 1500 Vdc Additionally the meter illumina tion lamps will slowly energize to about half bril liance Since the 3 5002filaments are in parallel with these lamps they will be responding in the same way If in ...

Page 117: ... the rig into a dummy load on the same table with my plastic encased television set You may have to scrape some paint off the mating metallic surfaces of the FT 7B enclosure if you live in a weak TV signal area A QST advertisement for the FT 7B reads Enough power to drive those linears The manual makes no mention of using the transceiver with an external amplifier but if you dig into the schematic...

Page 118: ...ugh switched broadband pi same The new version contained a sealed filter section matching networks The amplifier in in the excitation line to prevent 27 or 28 MHz put impedance is approximately 50 ohms Hash operation The band switch lacked the noise is prevented during the standby period by necessary contacts for 5 band use There was automatic application of beyond cutoff bias to no 10 15 meter pl...

Page 119: ... Editor I 41 41 4b C21 Y FROM FILAMENT HV BAND SWITCH B A TERMINAL 7 Fig 1 Part o f the SB 220VHF parasiticoscillation cure A consists o f installing Qdamping resistors RIA R2A in the amplifier cathode circuit and replacing the 3 5002 grid chokes with fuse resistors R3A R4A Note that the installation o f RIA and R2A also entails the addition o f a second filament blocking capacitor C32A Whether or...

Page 120: ...ldn t test it because I didn t have a mate for its power connector Here s one Fig 1 K8SS SB 220 modification lowers the voltage at the ANT RLY jack J1 from 125 at A to approximately 12 at B Short circuitcurrent through J1 is reduced from 25 m A in the unmodified circuit to 2 m A in the circuit shown at B J1 K 1 and the 0 02 pF capacitor are SB 220 parts Resistors are 1 4 W carbon film units unless...

Page 121: ...lableaccessory or ignitioncircuitnot powered duringcranking C Cometions for multiple transceivers and receivers If multiple transceivers or receivm are installed in the vehicle install heavy power conductorsto thetrunkor dashand taminate them in covered insdatedbus bats Connect all radio power leads to the bus bars This makes a neater installation and reduces the number of wires running under the ...

Page 122: ...ssed the desire for a color top inner shield of the case and the plate that would match equipment other than P 0 BOX 2234 Stamford CT 06906 connections on the tubes A STANDBY Heathkit As none of these problems seemed dif ficult to correct I began by purchasing Fig 1 Schemat c d agrarn of the mod f cations for standby sw tch two speed fan and fllament and a kit It worked quite protect on and I bega...

Page 123: ...nting location of the surge protection resistor If the specified resistor is used it can be mounted on existing screws off paddle switch was mounted on the front panel in a position on line with the two rocker switches and centered between the band switch and the loading control Care in drilling the mounting hole should be exercised so as not to chip the paint on the front panel The switch should ...

Page 124: ... the primary Two leads are now connected between the contacts of the time delay relay and one end of the resistor and terminal AW One side of the relay coil is connected to terminal block AE terminal no 2 The other coil terminal is connected to ter minal AW If you plan to operate your SB 220 on 235 volts only this completes the surge protection project If you are going to operate on 117volts you m...

Page 125: ...s as a comparable non doubling supply which yields a more efficient trans former design Here s why One layer of insulating paper is required between each layer of wires so fewer turns means fewer layers of paper The result is a transform er that has a high ratio of copper to paper and thus a relatively high power to weight ratio Excellent voltage regulation during current transients exactly what s...

Page 126: ...s the only HV negative path to chassis The peak discharge current can be substantial and damage to the meter shunt and movement can occur For example if the filter capacitors are at the 100 Vlevel when the interlock shorts the peak current through R3 is 100 V 0 82 fl I00A If a substantial voltage exists in the filter capacitors when the in terlock shorts R3 can be literally blown away by the disch...

Page 127: ...es the useful emission life of the two 3 5002sto only a few percent of what could have been realized if the tubes had been operated near the low end of the recom mended filament voltage range Although the filament circuit in the SB 220 needs no step start circuit to pro tect the tubes from high filament inrush current there is another good reason to add such a circuit to the SB 220 If the ampli fi...

Page 128: ...r immediately when this noise is heard Here s why In a full wave voltage doubler rectifier circuit there are two series connected filter capacitors ll One capacitor charges during the positive half of the cycle the other charges during the negative half of the cycle The two capaci tors discharge in series If one of the filter capacitors is not being fully charged by its rectifiers when current is ...

Page 129: ...most serious design weakness in the to decreasethe values of the grid to ground 5 T 2 a SB 220is its tendency to support an inter capacitors from 200 pF to 115 pF Three grade motor oil can also be used mittent VHF parasitic oscillation at roughly of these capacitors are used on each the SB 220is powered from120or 240V the no load I iyis vety close to 3 kV 110 MHz This problem is far from being 3 5...

Page 130: ...destringfor forwardbias not reverse bias likea Zener diode Thereplacementcircuitisshown hFig 5 The voltage can be controlled in 0 8 V steps by addingor subtractingdiodes T h i s allows you to easily set the zero signal idling anodecurrent for thetwo 3 500Zs The SSB modeidlingcurrent should be 160 to 200 mA for best linearity Adding Fun Break In QSK Full break in operation less than 3 ms turnaround...

Page 131: ...a n t e ous anodevoltage is swinging to its lowest point about 250 V and the total cathode current is 3 4 A I8Thus the driv ing resistanceat this point R is 117V 3 4 A 34 5 Qand incredibly P 117 V x 3 4 A 397 W Thus the resistance swings from nearly infiitywith positivedriving voltage allthe way down to 34 5 Q 19The drive power re quirement varies from 0 W to 397 W over the positive and negative t...

Page 132: ...ck during tuning It s also advisable to wrap some 1 inch 25 mm plastic electrical tape around the nuts on the HV feed throughinsulatorbeforeplug ging in the amplifier If you would prefer not towork around lethal voltages you can adjust the tuned inputswithoutapplyinghigh voltageto the anodes of the 3 500Zs Here s how 1 Make the appropriate changes in the tuned input circuits with the amplifier unp...

Page 133: ...onics Manuals Consumer Electronics Service Ops Manuals Available Pager Manuals Pager Service Programming Manuals Available Tektronix 7000 Series 60 Volume Plug In Manuals Set Amateur Radio Manuals Ham Radio Manuals by FTP Amateur Radio Manuals Ham Radio Manuals on CD Amateur Radio Manuals Large Collections on CD and DVD Thousands of Scanned Manuals Big Buck Distributing canned Manual on eBay Some ...

Page 134: ...ktronix Service Operating Manuals 1440 177 178 1L5 1S2 221 3B3 475 475A 528A 576 5A18N 5A19N 5A20N 5A22N 5A38 5A48 5B12N 5B40 5B42 5CT1N 5L4N 5S14N 647 7104 7503 7603 7613 7623 7623A 7633 7704A 7834 7854 7903 7904 7904A 7A11 7A12 7A13 7A15A 7A16 7A16P 7A18 7A18A 7A19 7A22 7A24 7A26 7A29 7B10 7B15 7B50A 7B51 7B52 7B53A 7B70 7B71 7B80 7B85 7B87 7B90P 7B92A 7CT1N 7D01 7D02 7D10 7D11 7D12 7D13 7D15 7D...

Page 135: ...DM5120 5520 FG501 FG501A FG502 FG503 FG504 MR501 P2220 P5100 P5200 P5205 P6007 P6009 P6011 P6015 P6021 P6022 P6042 P6046 P6053A P6054A P6058 P6061 P6063B P6101A P6105 P6106 P6106A P6107 P6108 P6112 P6120 P6130 P6131 P6133 P6138A P6139A P6156 P6202 P6202A P6243 P6246 P6248 P6407 P6430 P6460 P6462 P6563A P6602 PG501 PG502 PG505 PG506 PG508 PS5010 PS501 PS502 PS503A PS505 R146 RG501 RM529 S1 S3A S4 S...

Page 136: ...ep 72 Nov 72 Jan 73 Mar 73 May 73 Sep 73 Nov 73 Jan 74 Mar 74 77 V9 N1 Tektronix Manual Sets Libraries 16 Volume 7000 Series Scope Frames Service Manual Set 60 Volumes 7000 Series Plugin Manual Set 65 Volume 7000 Series Plugins Manual Set 79 Volume 7000 Series Operating Manual Set 26 Volume 5000 Series Service Operating Manual Set Miscellaneous 7854 App Notes Related Documentation 2 CD Set 7854 Pr...

Page 137: ...Discrete Ham Radio FTP Manual Listings Ham Radio Manual Set Library Listings Broadcast Studio Manual Listings We strive to produce the highest quality manuals we can However anyone can make a mistake We welcome constructive criticism and ask you to please bring any errors to our attention whether the material is paid for or is free Thank you Dave Miller AA4DF Mrs Hilda Diaz Miller Ms Jill Bryant M...

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