The 5351 A Microwave Frequency Counter covers the frequency range of 10 Hz to 26,5 GHz without an external mixer. Features Exceptional sensitivity of -40 dBm Tracking speed of 1GHz/second 60 ms acquisition time 100 measurements/second in automatic mode(HP-IB) Built-in microprocessor provide math capabilities Display: segmented 24 character, alphanumeric LCD(backlighted) Data output over HP-IB bus Many built-in features such as self-check, diagnostics, overload indicator, and keyboard lockout