Using the Inexpensive TB-105 Thrust Bearing with Low-Cost Rotators

摘要

The NTE/ECG U-105 rotator is very popular in the TV world. This rotator is also sold under the Phillips, RCA, Hy-Gain, and other brand names. Because it is inex-pensive, many of these rotators are used for lightweight ham antennas as well. According to the U-105 data sheet, you can use a 11/8-inch OD (outside diameter) to 2-inch OD mast, and the antenna/mast vertical load can be up to 100 pounds. However, this is a pretty small rotator and putting 100 pounds of weight on it seems like a real stretch. Also, there is no information on acceptable lateral forces. However, NTE/ECG also sells the TB-105 thrust bearing (the company calls it a "support bearing"), which is available for about $24 to $35 from CQ advertisers. Like any other thrust bearing, the TB-105 essentially can eliminate rotator vertical forces and sig-nificantly decrease rotator lateral forces.