Heathkit-T-2-manual 电路图 维修手册.pdf

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1、595-7 ASSEMBLING AND USING YOUR -II e.ahk ii- f Signal Tracer I Model T-2 THE HEATH COMPANY BENTON HARBOR, MICH. PRICE $1.00 RadioFans.CN 收音机爱 好者资料库 U SE F U L . , . , INFORMATION FOR KIT B U I L D E RS , . , Resistors are identified by a color code used in several bands around the resistors. There

2、are two general types of resistors. One, the uninsulated type, has the connecting wires bound around the ends. The other, the insulated type, has te wire connected internally and coming out the ends. The resist- ance code uses three bands or colors, while a fourth, usually silver or gold, indicates

3、the tolerance. The colors are arranged so that the first two indicate the first two figures of the resistance, while the third indicates the number of digits (zeros or multiplier) which follow the first two figures =mo=w. =mmmm f=Aw On uninsulated resistors, the body is the first figure, the end col

4、or the second figure, and the dot the number of digits. On insulated resistors, the band nearest the end is the first figure, the next band is the second figure and the third band the number of digits. =im 1W. WATTAGE. Resistors are rated as to wattage (power dissipation) according to size. The char

5、t shows approximate sizes which vary with manufacturers. To determine wat- tage size necessary multiply current through resistor in amperes by voltage drop across resistors in volts. Example -A plate loading resistor for a tube drawing 10 milli- amperes (.01 Amperes) has a voltage on one side of 300

6、 volts and on the other side 200 volts, giving a drop of 100 volts. Therefore 100 volts X .OlA. = 1 Watt. =1111 IW. A higher wattage resistor can always be substituted for smaller size. WATTAGE SIZES Uninsulated Body Color End Color Dot Color UNINSULfiTEO Examples /NSULATD TYPE Insulated First Ring

7、Second Ring Third Ring TYPE- Forth Band (olor llrMt Figure econd Figure Numb . r of Digit -FOr Tolerance B lack 0 B r own 1 Red 2 Ora nge 3 Yellow 4 Green 5 Blue fi V iolft 7 Gr ey 8 White 9 RF.!l!TA NCF. nr OIUI 50 250 1500 o.ooo 220,000 1 Meg ohm 0 None 1 0 2 00 3 .ooo 4 0,000 5 00.000 6 000.000 7

8、 0.000.000 BROWN RED ORANGE 8 00.000.000 1 2 000 9 000.000,000 Some Popular Sizes of Resistors BODY OR lIll!T BAND .NND OR !1-:0NU 8,ND G ree-n Black Htl G n tn B rown (; rPen Or a nge B lack Hrd Hd B rown B lack The fourth ring o r othe r end may b e silver (10% tole r a nce) or goll (5% t olr a ne

9、) or it may he omitted entir ely which indicatPs 20!. t olranc. Condenser Code Condensers use the same code as resistors and are read in micromicrofarads. .;, BROWN RED ORANuE 1 2. 000 DOT OR TlllRD HAND B lack Brown HPd Orang ! Yellow Green If there is one row of dots, they are read in direction of

10、 arrow or if manufacturers name appears in the same direction as name. If two rows of dots appear, it can either be of two different codes: The RMA or the A WS (American War Standard). In the RMA, the top row of dots are the first three figures (carried to three figures), the bottom row are left to

11、right the voltage rating, tolerance, and decimal multiplier. In the A WS code, the top row of dots are the first three figures while the bottom row are, left to right, characteristic, tolerance, and decimal multiplier. RED GREEN BROWN z 5 0 20 MMF :; .000 ZS MF Examples RMA BROWN RED GREEN BROWN 1 2

12、 5 0 1250 MMF =.OOl25MF 1 DOT ALWAYS BLACK AVVS ulEEN BLACK BROWN 5 0 0 500 MM F = .0005 Some Commonly Used Sizes of Condensers MMF. MF. FIRST DOT SECOND DOT 10 .OOOGl Brown Black 53 .00005 Green Black 100 .0001 Brown Black 250 .00025 Red Green 500 .0005 Green Black 1000 .001 Brown Black 3000 .003 O

13、range Black 10,000 .01 Brown Black The tolerance rating corresponds to the color code, i.e., red -2%, green -5, etc. THIRD DOT Black Black Brown Brown Brown ed Red Orange The voltage rating corresponds to the code multiplied by IOO. Example: Orange dot -300 volt rating; Blue -600 volt rating. 12-21-

14、51 RadioFans.CN 收音机爱 好者资料库 HKIT MODEL T2 SIGNAL TRACER Size: 9 wide x 6 high x 5 deep USES 2= signal from antenna to speaker-Enables quick determination of defective stage. es intermittents used on F.M.and T. V.Receivers -record players and record changers : microphones -peaker allows checking of re

15、ceiver speaker by substitution ersal output transformer allows servicing of sets without output transformer and speaker- er mines correct impedance match for unknown speakers, tubes, etc. CIRCUIT a diode test prod-6SH7 Hi gain Amplifier o tput tube-6X5 rectifier-4 P. M. Speaker ersal output transfor

16、mer rates from Audio frequencies to approx. 200 Mc. :a:fe for AC-DC receivers-105-120 VAC transformer operated Page 1 RadioFans.CN 收音机爱 好者资料库 ASSEMBLING THE HEATHKIT MODEL T-2 SIGNAL TRACER The construction of the Heathkit Signal Tracer is not difficult but consideration should be given the fact tha

17、t a test instrument will be useful for many years and care taken in construction will be repaid many times. Test equipment is the best assistant available in service and research work and it deserves the most careful workmanship possible. Thoroughly study and familiarize yourself with the instructio

18、ns, pictorial diagrams and circuit. Do not rush the construction. Make a good mechanical joint of each connection, then solder it with best quality rosin core radio type solder. (DO NOT USE FLUXES OR ACID CORE SOLDER.) Hold each joint rigid while solder cools and then test by attempting to pull join

19、t loose. Most difficulty in construction results from poor soldering (and use of wrong solder) anc:l reversed connections (remember that in working on the bottom of the chassis and rear of panel that all locations are reversed). Check the parts carefully against the parts list. Identify each part (u

20、sing the charts on covers of instruction manual). Be sure to check the packing to avoid throwing away any of the small parts. Mark the values of condensers and resistors on the schematic diagram beside the part number. From time to time, small changes in parts will be made by the Heath Company. All

21、parts sup- plied will work just as well as the part for which it was substituted. 47, 000 ohms resistors (which is the new radio manufacturers rating for 50,000 ohms) may be substituted for 50,000 ohms or a one watt resistor may be substituted for one-half watt, etc. All substitutions will be of equ

22、al or better quality than the original and will be made in order that a minimum delay will occur in filling your order. The newer types of insulated resistors have a higher wattage rating. The t watt size is now rated at % watt and these are used in this kit. Bolts and nuts are counted mechanically

23、and if a few are missing please secure locally. Resistors, condensers and potentiometers have a normal tolerance rating of plus or minus 20% unless marked otherwise. Therefore, a 1 megohm unit may test between 800,000 and 1,200,000 and be satisfactory. Heathkit circuits are designed to accommodate t

24、hese variations. Soc- ket connections are numbered on the bottom of the sockets. Sockets are fastened into the chas- sis with the wavy metal rings which fit into the groove in the side of the socket. To install, hold one end of the ring in the groove and the balance of the ring is then forced over t

25、he socket and into the groove with a screw driver. Note the direction of the keyways in the sockets from the pictorial diagram. Begin the construction by mounting the sockets, power transformer, output transformer and bath- tub condenser, adding solder lugs where indicated. Note: Solder wires to out

26、put transformer lugs #1, #3, and #5 before mounting. Wire the power supply section first followed by the filaments and ground connections. The resistors and molded condensers are now added. Assemble the panel by mounting.the several jacks. The jacks are held in place by the special washer with sharp

27、 points which is forced over the body of the jack. Mount the speaker grill and speaker and the upper selector switch. The panel is held to the chassis by the gain control potentiometer and the lower rotary selector switch. Complete the wiring by making all connections from the panel to the chassis.

28、Install the line cord. Assemble the prod as shown on the circuit diagram. Remove enough of the shielding on the cable to prevent shorting of the crystal. Solder the short ground BRAID to the shield. The cable with crystal attached is inserted into the prod (having first removed the cap from the sold

29、erless tip of the test prod) and the lead from the crystal pulled through the hole in the prod tip. This lead is wrapped around the groove in prod tip and the cap replaced locking it in place. To avoid strain on the crystal lead, it is suggested that several match sticks be pressed into the prod bes

30、ide the shielded lead makingthe cable tight in the prod. Install the phone plug on the other end of the cable as shown. Upon completion of the wiring, recheck all connections. A suggested way is to follow each con- Page 2 nection in the instrument and mark if on the circuit diagram with a colored pe

31、ncil. In this manner, any connections overlooked or incorrect will be disclosed. If wiring is in order, insert tubes and connect to llOV 60 cycle AC. After warm up period, advance the gain control and touch prod tip. If loud hum is heard in the speaker (providing switches are set in correct position

32、), the tracer is in proper operating order. USE OF SIGN AL TRAC ER The gain control determines the sensitivity of the instrument and allows the signal being followed to be adjusted to a suitable volume. The slide switch 094 should be in the internal position. The selector switches should be in posi-

33、 tions 4 and 5 to properly match the 6K6 tube in this instrument. To trace a receiver, set the dial of receiver under test to known local station or preferably a signal from a test oscillator. Turn gain control full on, connect ground clip of tracer prod to B-. (On AC-DC radios, a small potential ma

34、y exist which may be eliminated by reversing either the plug on radio or tracer or both.) Note: B-and chassis may not be at the same potential in some AC-DC receivers. Hum and distortion may be minimized by placing a condenser of afew MMF in series with the test prod. A reduction in signal strength

35、due to detuning is to be expected when checking receivers having relatively large inductances and small capacities in the tuned circuits. Start at the antenna coil and touch the prod tip to fir st the secondary, continuing through the RF, and IF coils (always to the high or plate and grid sides of t

36、he coils) continuing through the audio section by connecting progressively to the grid and plate of each section at tube socket. When the signal stops, the difficulty lies in the stage just precding. To illustrate-if the signal appears at the plate or primary connection of a coil but not at the seco

37、ndary or grid of the coil, the fault is between the plate and grid. The gain of each stage is indicated by the amount the gain control of the tracer must be reduced to maintain equal volume. Power supply filters may be checked by touching the prod to each section and noting the reducUon in hum (no r

38、eduction indicates de- fective filter condenser). Distortion, noise or hum may be followed through a radio in the same manner and isolated. The Heathkit Signal Tracer may be used for many other trouble shooting purposes which appear desirable to the user. The crystal diode in the probe is in effect

39、a crystal detector which will respond to any frequency up to 200 megacycles. The selector switches make 30 different impedance ratios available which make the instrument a valuable test speaker. To use as a test speaker for receivers or amplifiers with output trans- formers, connect to jacks C (comm

40、on or grounded side) and VC (voice coil) with slide switch to external. To use as a test speaker for receivers or amplifiers without an output transformer, c6nnect to jacks P and B+ (for single ended output) or P B+ and P (for push pull output) with slide switch in internal position, and adjust the

41、selector switches for proper matching to the tubes using the chart on the panel. A mismatch of 30 percent will not adversely affect operation. When used as a test speaker, be sure the power is turned off turning the gain control all the way counter clockwise till the switch clicks. The transformer c

42、an be used as a matching transformer only, by connecting the amplifier or receiver as above and C and SEC terminals to an external speaker. The sHde switch should then be in the external position. To use the tracer as an audio amplifier or small public address system, connect either a phono- graph p

43、ickup or high impedance crystal microphone to the input terminals and use either the in- ternal speaker or a remote external speaker. For visual signal tracing, insert the AC test prod from a vacuum tube voltmeter into the P connection. Connect the GND connection of the tracer to the common or GND c

44、onnection of the VTVM. The VTVM should be set on the correct AC scale. Signal levels and gain per stage may be read directly in volts or db. In checking inter- mittents, the tracer and VTVM may be left at a known setting and will indicate any change in- stantly. The P connection may also be connecte

45、d to an oscilloscope for visual tracing. Page 3 IN CASE YOU HAVE DIFFICULTIES 1. Recheck entire wiring. Most cases of troubl result from incorrect or reversed wiring. 2. Check all voltages at the sockets. Measurements given below were taken with an 11 megohm input resistance Heathkit VTVM. A normal

46、variation of+ or - 15 % are to be expected. All are measured between chassis and socket pin. 6SH7 6K6 6X5 Pin 1 0 0 0 2 5-6%VAC. 0 0 3 0 250 to 280V. .200-240VAC. 4 0 (No Signal) 250 to 280V. Not Used 5 0 0 200-240VAC. 6 25-35V Not Used Used as Tie Point 7 0 5 to 6%VAC. 5 to 6%VAC. 8 90 -120V. No Si

47、gnal 13 to 18V. 260 to 300V. 3. Check phone plug and test prod for shorts to shielding. 4. If oscillation is evident, try reversing the brown and blue leads form the output transformer, as shown in the pictorial diagram. 5. If residual hum level is too high, try reversing the two black primary leads

48、 from the power transformer. SERVICE In event continued operational difficulties of the completed instrument are experienced, may we remind you that the Heath Company has provided a technical consultation service. Every effort will be made to assist you through correspondence. May we emphasize that

49、in all correspond- ence this instrument should be referred to as the Model T-2 Signal Tracer. The facilities of the Heath Company Service Department are also available. Your instrument may be returned for inspection, repair and calibration for a service charge of $3.00 plus the cost of any additional material that may be required. This service policy applies only to com-