07 cf351 f07 superheterodyne receiver
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CF351 F07 - 1
Unclassified
4 Hour Conference, W/ 7Hr PE1
Safety & Environmental Impact is “LOW”
TIII:
CF351 F07 - 2
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
Action:Given a schematic diagram, answer questions pertaining to Ckt
operation, Transmitter & Receiver group concepts and signal tracing procedures.
Condition: W/O References.
Standard: Answer 7 of 10 written questions correctly as well as troubleshoot & locate a malfunction W/in 20 minutes.
20 seconds
CF351 F07 - 3
All electronic communications both in defense as well as the private sector are centered around the very basic transmitter & receiver groups.
This lesson will concentrate on the Receiver group w/ an overview in a block diagram of the transmitter group.
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
Overview
CF351 F07 - 4
FMFM; Frequency Modulated
The FCC, Federal Communications Commission grants all License, & call letter designations. 3 call letter stations were grandfathered in due to there existence before the establishment of the FCC in 1932.
Transmitter Group
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
Overview;Overview;
WLWCincinnati
OH.
KLTPittsburg
Pa.AM AM ; Amplitude Modulated
CF351 F07 - 5
OSCILLATOR1000 KHZ CW
TRANSMITTER – Generates a continuous wave (CW) carrier frequency with an additional signal intelligence impressed upon it, thus becoming an Amplitude Modulated (AM) signal. Once powered up the AM signal is put on the air as transmission RF waves via an antenna.
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
TRANSMITTER GROUPTRANSMITTER GROUP; OSCILLATOROSCILLATOR
Modulator
CF351 F07 - 6
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
TRANSMITTER GROUPTRANSMITTER GROUP; MODULATORMODULATOR
A. Input acquired from OSCILLATOR (1000 KHZ) B. A 2nd signal from transducer is mixed with 1000 CW to
produce and Amplitude Modulated (AM) signal or Carrier Transmission.
Modulatoror
Mixer
OSCILLATOR1000 KHZ CW
TRANSDUCER{Microphone}
PWR Amp
CF351 F07 - 7
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
TRANSMITTER GROUPTRANSMITTER GROUP; POWER AMPLIFIERPOWER AMPLIFIER
HometownUSA
A. Power Amplifier Boosts the AM signal up and applies it to the Antenna.
B. The AM – RF energy is transferred to the atmosphere in the form of Radio Frequency (RF) radiation.
POWER AMPLIFIER
Modulatoror
Mixer
OSCILLATOR1000 KHZ CW
TRANSDUCER
Dear Ma
Dear Ma
Receiver
CF351 F07 - 8
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
RECEIVER GROUPRECEIVER GROUP; ANTENNAANTENNA
RF RADIATION
Antenna (aerial)
Is the device that intercepts the AM electromagnetic radiation waves. As
the waves pass and are cut by the aerial, small amounts of current
will be induced upon it.
HometownUSA
Tuner
USPS
CF351 F07 - 9
HometownUSA
ANTENNA
TUNER1000 KHZ
A: Selects one signal from the many on the aerial by tuning a Parallel LC Tank circuit to resonate @ 1000 KHZ.
B: The tuner is capable of tuning-in all the AM frequencies with in the AM spectrum of 540 KHZ – 1610 KHZ.
C: The selected frequency of 1000 KHZ is applied to the converter or mixer.
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
RECEIVER GROUPRECEIVER GROUP; TUNERTUNER
Tuner PC 38
CF351 F07 - 10
Tuner
O
Antenna
T3T2Q1
3
2
4
5
1
7
6
T1
R2
6.2 K
R1
47 K
R3
22 K
C3
.01 f
R4 1 K
C1 A
C1 B
TIII: SUPERHETERODYNE RECEIVER
RECEIVER GROUP; PC Antenna Antenna & TunerTuner.
PC 38
Local Osc
CF351 F07 - 11
PC 38, LO
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
RECEIVER GROUPRECEIVER GROUP; Local Oscillator [LO]Local Oscillator [LO]
CONVERTER or
MIXERLOCAL OSCILLATORLOCAL OSCILLATOR1455 KHZ
TUNER1000 KHZ
HometownUSA
1. The LO Signal output is always the Tuner Frequency, Plus 455 KHz Regardless of what AM signal is
tuned.2. It is tuned simultaneously with the RF Tuner.3. The output would be 1000 + 455 = 1455 KHZ CW.4. The output of 1455 KHZ is sent to the Converter or Mixer.
CF351 F07 - 12
Converter / Mixer
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
RECEIVER GROUPRECEIVER GROUP; Local Oscillator [LO] Local Oscillator [LO]
PC 38
Tuner
LO
OO
Antenna
T3T2T2Q1
33
22
44
55
11
77
66
T1
R2
6.2 K
R1
47 K
R3
22 K
C3
.01 f
R4 1 K
C1 A
C1 B
CF351 F07 - 13
PC 38, Mixer
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
RECEIVER GROUPRECEIVER GROUP; Converter / MixerConverter / Mixer
MaMaUSAUSA
The 1000 KHZ from the Tuner is heterodyned with a 2nd signal from the Local Oscillator [1455 KHz] to produce 4 different output frequencies.
F1RF
F2LO
F2+f1SUM
f2-f1 f2-f1 DIFFERENCEDIFFERENCE
1000 KHZ
1455 KHZ
2455 KHZ
455 KHZ
orCONVERTER
MIXER
RF TUNER1000 KHZ
LO1455 KHZ
INTERMEDIATEINTERMEDIATEFREQUENCYFREQUENCY
(IF)(IF)
HometownUSA
CF351 F07 - 14
IF Amp
TIII: SUPERHETERODYNE RECEIVER
RECEIVER GROUP; Converter / MixerConverter / Mixer
PC 38
Tuner
LO
Converter
O
Antenna
T3T2Q1
3
2
4
5
1
7
6
T1
R2
6.2 K
R1
47 K
R3
22 K
C3
.01 f
R4 1 K
C1 A
C1 B
455 KHz
CF351 F07 - 15
PC 39, IF Amps
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
RECEIVER GROUPRECEIVER GROUP; IF AmplifierIF Amplifier
IF amplifier has the most receiver gain and is made up of 2 cascaded high gain amplifiers tuned to 455 KHZ.
Sensitivity and bandwidth [T4 & 5] are determined by this stage.
The [IF] output is sent to the detector (demodulator).
IF Amplifier455 KHZ
orCONVERTER
MIXER
RF TUNER1000 KHZ
LO1455 KHZ
MaMaUSAUSA
PC 38
PC 39
CF351 F07 - 16
Detector
TIII: SUPERHETERODYNE RECEIVER
RECEIVER GROUP; IF AmplifiersIF Amplifiers
PC 39
T4 T5
Q2 Q3
R5
56 K
R7
10 K
R8
47 KC4
10 f
T3 s
Operate
Test
R 11 2.7 K
R 13 100 K
R 12 5 K
15
C 11 .0
5 f
D 1
1710 13
9 12
11 14
8
C6 10 f
11stst IF IF AmpAmp
2nd IF 2nd IF AmpAmp
DetectorO
C8
C7
R6 C9
C10R9 R10
38 card
CF351 F07 - 17
PC 39 Detector
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
RECEIVER GROUPRECEIVER GROUP; DETECTOR DETECTOR OR DEMODULATOR DEMODULATOR
Rectifies the modulated signal, then filters out the 455 KHz Leaving only the audio frequency or intelligence of 50 Hz – 20 KHzWhich is sent to the AF amplifiers.
Detector
IF amplifier455 KHZ AM
orCONVERTER
MIXER
RF TUNER1000 KHZ
LO1455 KHZ
MaMaUSAUSA
Your Favorite
Son
455 AM Rectified Filtered
PC 38 PC 39
CF351 F07 - 18
TIII: SUPERHETERODYNE RECEIVER
RECEIVER GROUP; DETECTORDETECTOR or DEMODULATORDEMODULATOR
PC 39
38 card
Filter
O
T4 T5
Q2 Q3
T3 s
Operate
Test
R 13 100 K
R 12 5 K
15
C 11 .0
5 f
D 1
Detector
1710 13
9 12
11 14
8
C6 10 f
1st IF Amp
2nd IF Amp
DetectorDetector
C4
10 f
R5
56 K
R7
10 K
R8
47 K R11 2.7 K
R6 C1 R9 C9 R10
C10
C8
AGC
CF351 F07 - 19
PC 39, AGC
TIII: SUPERHETERODYNE RECEIVER
RECEIVER GROUP; AVCAVC or AGCAGC
Automatic Volume Control or gain control is taken at the detector (demodulated and fed back to the first IF amplifier base. Required to overcome atmospheric and terrain conditions that adversely affect signal strength between the transmitter & receiver.
AVC or AGC
Detector
IF Amplifier455 KHZ AM
orCONVERTER
MIXER
RF TUNER1000 KHZ
LO1455 KHZ
PC 38 PC 39
CF351 F07 - 20
All Ckt PC 39
TIII: SUPERHETERODYNE RECEIVER
RECEIVER GROUP; AVC or AGCAVC or AGC
PC 39
R6 C1 R9 C9 R10
C10
C8
O
T4 T5
Q2 Q3
T3 s
Operate
Test
R 13 100 K
R 12 5 K
15
C 11 .0
5 f
D 1
AVC
AVC
1710 13
9 12
11 14
8
C6 10 f
1st IF Amp
2nd IF Amp
Detector
R5
56 K
R7
10 K
R8
47 KC4
10 fR 11 2.7 K
PC 38
CF351 F07 - 21
TIII: SUPERHETERODYNE RECEIVER
RECEIVER GROUP; 11stst & 2 2ndnd IF Amp, Detector, AVC IF Amp, Detector, AVC or AGC.AGC.
PC 39
38 card
Filter
O
T4 T5
Q2 Q3
T3 s
Operate
Test
R 13 100 K
R 12 5 K
15
C 11 .0
5 f
D 1
Detector
AVC
AVC
1710 13
9 12
11 14
8
C6 10 f
11stst IF IF AmpAmp
2nd IF 2nd IF AmpAmp
DetectorDetector
R5
56 K
R7
10 K
R8
47 KC4
10 fR 11 2.7 K
R6 C1 R9 C9 R10
C10
C8
PC 39
Audio Amps
CF351 F07 - 22
PC 40
TIII: SUPERHETERODYNE RECEIVER
RECEIVER GROUP; AUDIO AMPLIFIERAUDIO AMPLIFIER
AUDIO AmplifiersAUDIO Amplifiers
AVC OR AGC
Detector
IF Amplifier455 KHZ AM
orCONVERTER
MIXER
RF TUNER1000 KHZ
LO1455 KHZ
3 stages: Audio preamp Audio driver Audio push- pull
AUDIO AMPLIFIERAUDIO AMPLIFIER
PC 38 PC 39 PC 40
CF351 F07 - 23
Audio Pre Pre AmpAmp
Audio DriverDriver
Audio Push Push PullPull
Q4
Q5
Q6
Q7
18
2119
20
24
27
31
29
28 O
22
23
25
26
T6
T7
R18
C13
C14
R15
R14
R17
R16
C12
R20
R19
R21C15
D2 R2
5
R24
R23
C16
E
30
TIII: SUPERHETERODYNE RECEIVER
RECEIVER GROUP; AUDIO AMPLIFIERAUDIO AMPLIFIER
PC 40
Trouble Shoot
CF351 F07 - 24
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
RECEIVER GROUPRECEIVER GROUP; Trouble shooting procedure.Trouble shooting procedure.
2
4
3
18
20
19
21
23
22
27
31
26
24
25
29
9
11
10
12
14
13
15
PC38 PC39 PC40
Tone, PC 40 OK
Tone, PC 38, 39, 40 OK
Tone, PC 39, 38 OK
11stst
2nd2nd
3rd3rd
No TonePC 40
Malfunctioning
No TonePC 39
Malfunctioning
No TonePC 38
Malfunctioning
Lesson Test
CF351 F07 - 25
Answers 1-9
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
Review QuestionsReview Questions;
1. Where does heterodyning take place in the receiver taught? ________________
2. The IF amplifier is tuned to the __________ frequency of _______ KHz.
3. What are the block diagram stages of a Super heterodyne receiver?
___________ ___________ ____________
___________ ___________ ____________
___________ ___________
4. What components make up the Local Oscillator & Feedback? ___, ____, ____.
5. What is the propose of the AVC [AGC] Ckt in the receiver? ______________
6. What are the two actions needed to Demodulate an AM carrier?
_______________, _____________.
7. What type of coupling is used in the RF & IF section of the Super-Het-Receiver discussed in this lesson? _____________________
8. T6 Secondary in the audio amplifier is center tapped to provide 2 signals that are the ________ in amplitude and the ____________ in polarity.
9. What is the purpose of Q5 Driver Amp in PC 40? _____________________
CF351 F07 - 26
Answers 10- 21
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
Review QuestionsReview Questions;
10. What is the frequency range of a standard AM broadcast receiver? _____________
11. Frequency conversion can handled by two stages, or only one. What are they called? ____________ , ________________ .
12. After a receiver is properly aligned, it should have maximum _______ & ________
13. What is the frequency of the Local Osc, [LO] ? __________
14. What is the main use of the Audio output Transformer [T7] ? _________ _______
15. What section of a super heterodyne receiver provides the most gain? _____
16. Where & what is the first test in troubleshooting an inoperative receiver ? _____ , ____________ _______________
17. When troubleshooting the superhet receiver, which section [card] do you check first? _____________ ______
18. What is the purpose of Cr1 [D1] ? _________________ ______________
19. When aligning the super heterodyne receiver , Which section is aligned first ? ______________ ___ _______
20. What method of troubleshooting is used on the super heterodyne receiver ? _________ __________; _______ ________ ___________ .
21. There are four frequencies produced by heterodyning. What frequency is used by the super heterodyne receiver ? ___________________
CF351 F07 - 27
PE Set UP
PE Write UP
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
Lesson TestLesson Test;
Lesson Test:
Standard:
10 Questions W/in 20 Minutes.
70% Minimum Accuracy.
Reference: NONE
RF TUNER CONVERTER ORMIXER
IF AMPLIFIER DETECTOR
AF AMPLIFIER
SPEAKERSPEAKERLOCAL
OSCILLATOR
CF351 F07 - 28
PE Write UP
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
PE Write UpPE Write Up; Example 1.Example 1.
Card TP Indication Test Equip3939 TP 15TP 15 F-GenF-Gen
3939 TP 9TP 9 F-GenF-Gen
3838 TP 2TP 2 F-GenF-Gen
3838 TP 3TP 3 11.89 VDC11.89 VDC DMMDMM
3838 TP 2TP 2 280mVDC280mVDC DMMDMM3838 TP 4TP 4 280mVDC280mVDCDMMDMM3838 TP 2/4TP 2/4 0/0 0/0 DMMDMM
Card: 3838Circuit: LOLOComponent: Q1Q1Malfunction: ShortShort
CF351 F07 - 29
PE Set UP
TIII: SUPERHETERODYNE RECEIVERSUPERHETERODYNE RECEIVER
PE Write UpPE Write Up; Example 2.Example 2.
Card TP Indication Test Equip3939 TP 15TP 15 F-GenF-Gen
3939 TP 9TP 9 F-GenF-Gen
3939 TP 12TP 12 F-GenF-Gen
3939 TP 10TP 10 12 VDC12 VDC DMMDMM
3939 TP 9TP 9 780mVDC780mVDC DMMDMM3939 TP 11TP 11 220mVDC220mVDCDMMDMM3939 TP 10/9TP 10/9 Hi/Hi Hi/Hi DMMDMM
Card: 3939Circuit: 11stst IF AMP IF AMPComponent: Q2Q2Malfunction: OpenOpen
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