Deutsche Welle: Radio Training Centre

Magnetic sound recording

Regular Maintenance of Tape Recorders

A. Routine Cleaning and Checks
To be performed daily or weekly by operators or junior technicians

1. Cleaning

required:

- cloth
- spirit
- water
- cotton pads

clean

- Surface
- Heads
- Tape guides
- Idlers
- Capstan
- Pinch roller

2. Visual Checks

look for

- loose parts
- missing screws
- bent, distorted parts
- defective parts
- function of tape lifters

B. Regular Tests
To be performed monthly or biannually by maintenance technician

3. Mechanical Tests

Checks: Adjustments:

required:

- spring balance
- service manual
- magnetic tape
- tools
- reel

4. Demagnetise

5. Play-back Test

required:

- test tape
- level meter
- load resistor

Play test tape on the machine and check output with level meter: - Play-back level - Frequency response all o.k.? not o.k.? go to 6. go to 8.

6. Recording Test

required:

- a.f. generator
- level meter
- virgin tape
- load resistor

all o.k.? not o.k.? go to 7. go to 9.

7. Sound Quality Tests

required:

- a.f. generator
- distortion meter
- level meter (with weighting filter)
- wow & flutter/drift meter
- load resistor
- virgin tape

not o.k. go to 8. o.k. not o.k. o.k.

C. Full Audio Alignments
To be performed by an experienced maintenance technician after repair or if required

8. Play-back Alignment

required:

- test tape
- level meter
- tools
- load resistor

all o.k.? go to 6.

9. Recording Alignment

required:

- virgin tape
- a.f. generator
- level meter
- tools
- load resistor

all o.k.? go to 7.

Magnetic sound recording