Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5500901 | Frequency response adjusting device | Michael P. Geraci, Donald R. Hagen | 1996-03-19 |
| 5157371 | Potentiometer retention mechanism and method of mounting | Gerald H. McDonald, Donald R. Hagen | 1992-10-20 |