Model R98B Cartridge

The R98B is a replacement microphone cartridge for the 577B microphone. To replace the present cartridge with the R98:

1. Disassemble the case as described above.
2. Using a low-wattage (50 W or less) soldering iron, unsolder the leads connected to the present cartridge.
3. Bend the two cartridge-retaining tabs inward (toward cartridge).
4. Slide the cartridge out of the chassis module, remove the retaining ring from around the screen, and remove the O-ring from the rear of the cartridge.
5. Place the retaining ring and the O-ring on the replacement cartridge and slide the replacement cartridge into the chassis module.
6. Bend the cartridge-retaining tabs outward (away from cartridge).
7. Solder the leads to the cartridge terminals. See Figure 2 for proper lead connections.
8. Insert chassis module in case front and switch button in case back.
9. Fasten case halves with previously removed screws.