Grundig TK 24 Tape Recorder Service Manual
Service manual for the Grundig TK 24 four-track tape recorder, a comprehensive workshop reference covering both mechanical and electrical repair. The mechanical section provides detailed guidance on lubrication schedules, functional operation of the drive and tape transport mechanisms, coupling arrangements, belt routing, and the auxiliary tools required for disassembly and adjustment. The electrical section includes complete tube-based circuit diagrams for recording and playback channels, frequency response curves, measurement and equalization circuits, relay schematics, contact assemblies, and winding specifications. All technical measurements and performance parameters are documented to support troubleshooting and restoration work on this classic reel-to-reel machine.
Table of Contents:
- Recording Input Sockets TK 120/140
- Input impedance over 100 kΩ single-ended
- Microphone/Radio input impedance at socket Ms. 1 or directly at Ms. 2
- Input impedance 100 kΩ at Ms. 3
- Control voltage at Ms. 4 after connection
- Frequency response 20 Hz to 20 kHz
- Input setting: Micro/Radio 1.2
- Measurement: Head microphone at 100 kΩ parallel to head system
- Speaker setting: Speaker Start
- Regler and Schalter: Pegelregler auf, Klangregler hell
- Amplification
- Verification of input sensitivity with 1000 Hz
- Input voltage drop of 100 mV required at input for voltage follower
- Damping of input stage to speaker input
- Voltage measurement and output control of EM 84 controller
- Final setting with R 21
- Frequency measurement
- Frequency measurement at radio microphone input
- Frequency at 66 Hz
- Frequency at 12000 Hz
- Frequency response spike
- Intermediate values see recording curves
- Rated input voltage maximum
- Input short-circuit
- Input open-circuit
- During incorrect HF-Premagnetization and discharge, maximum voltage at speaker output allowed
- Final stages
- Measurement at playback parallel to 5 Ω load
- Damping of measuring circuit
- Distortion and distortion factor
- Output voltage of 333 kHz
- Frequency response
- Frequency response and distortion factor
- Foreign voltage
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Document Details
- Format
- Pages
- 24
- Size
- 9.0 MB
- Category
- Audio & HiFi