| Number | Name | Date | Kind |
|---|---|---|---|
| 3809810 | Walker et al. | May 1974 | |
| 4028498 | Mehaffey et al. | Jun 1977 | |
| 4286118 | Mehaffey et al. | Aug 1981 | |
| 4726054 | Molnar | Feb 1988 | |
| 4972457 | O'Sullivan | Nov 1990 | |
| 4991197 | Morris | Feb 1991 | |
| 5113431 | Horn | May 1992 | |
| 5130662 | Jorgensen et al. | Jul 1992 |
| Entry |
|---|
| Jones, "The Pye TVT Approach to Audio Control Systems", International Broadcast Engineer, vol. 6, No. 122, pp. 4-6, 8-11, Mar. 1975. |
| Ullah, "Master Switching Control Panel for Broadcast Studios", ABU Technical Review (Japan), No. 69, (Jul. 1980). |