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Telephone Hybrid Alignment

In this world of changing audio, some things remain the same. That includes interfacing to most phone systems. In broadcast facilities, we sometimes neglect to keep our ancillary equipment at peak performance. Certainly one of those areas could include your telephone hybrids.

Be sure to occasionally evaluate for YOURSELF the health and operations of your telephone interface equipment. Those devices can drift out of adjustment over time, not to mention operators who like to “tweak.” Most of the common problems are perceived on the caller’s end, including low volume or an echo effect. Usually, a little preventative maintenance is easily accomplished on these units.

Aside from feeding hybrid’s proper levels and matching their outputs properly, two of the main adjustments are “Null” and “Main Send.” You can find the proper adjustment procedures in your manual, and if you don’t have your manual you can probably find it online. The adjustment on these devices is very similar between brands.

Most of your equipment is probably used on a daily basis, and problems are quickly noticed.

That may not be the case with your phone hybrids.


In the last week’s Audio Tip (Nov. 5), the wording caused some confusion. Obviously, AC-3 is the ATSC standard. In addition, the language descriptors are located in the PSIP. The author apologizes for any confusion. The overall message was to ensure understanding of the approaching standards deadline.