- Wide Measuring Range Up to 3.5 GHz
- Bright Nine Digit LED Display
- Period Mode for Accurate Low Frequency Measurement
- Totalize Mode Permits Counting of Individual Events
- Accurate TCXO Time Base
BK Precision AT 21 Model Antenna is primarily designed for use with handheld frequency counters and spectrum analyzers. It is a recommended accessory for BK Precision Model 1803D 200MHz Frequency Counter; Model 1804 Low Cost 550Mhz Frequency Counter; Model 1823 Universal 175 MHz Frequency Counter and the BK Precision Model 1856C Multifunction 2.4 GHz Frequency Counter with Period and Totalize functions. It is also recommended accessory for BK Precision Models 2625, 2630 and 2635 1.05GHz Spectrum Analyzers. Also known as BK Precision AT21 AT-21 110110.