Vintage BK Precision 1820 Universal Frequency Counter

BK B&K Precision Model 1823A 2.4GHz Universal Frequency Counter PARTS

Optoelectronics Frequency Counter Model 7010A - 600 MHz Untested

OPTOELECTRONICS OPTO-7000 FREQUENCY COUNTER - No Power cord

Optoelectronics Frequency Counter Model 7010A - 600 MHz - UNTESTED

Vintage BK Precision 1850 Universal 6 Digit Frequency Counter

TFC-1000L Multifunctional High Precision Frequency Counter Meter 8-Bit LED Displ

DataScan MODEL C1400 10HZ-1..4GHZ FREQUENCY COUNTER * Untested