Fl-2100B Amplifier
Bias Modification
For Svetlana and Taylor 572B tubes
Technical Bulletin
File No.: | TB-9627 | Date: | July 16, 1996 |
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Model: | FL-2100/B | Serial No. Range | Complaint unit |
Problem: | Oscillation causes burned components when using Svetlana & Taylor 572B tubes. |
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Expected Results of Modification: | Improve Circuit. |
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Component Value Changes: Main Unit | |||
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Part Location No. | From | To | New Part No. |
Added/Deleted Component: Main Unit | |||
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Part Location No. | Device Type | Added/Deleted | New Part No. |
Chassis | |||
10D10 | A | G2090002 | |
1000uF 25WV | A | K40149005 | |
22 ohm 1W | A | J20306220 |
Procedure | |||
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See Diagrams |
Bias Level Adjustment After the modification is completed, you must adjust the bias level. With the function switch in the operate position, activate the amp relay with no RF drive applied. Adjust R4 for an idling current of 0.03 amps on the IP meter.
DO NOT adjust to 0.090 as in manual.