The Optoelectronics® M1 HandiCounter® is a full range, 10Hz to 2.8GHz, pocket sized instrument that represents a substantial leap forward in features and capabilities. The M1 uses an embedded micro-controller along with the powerful OE10 counter IC to provide advanced features such as Digital Filtering, Digital Auto Capture® (auto hold), Data Storage, and Serial Data Output.

The M1 excels as a very high performance handheld, pocket sized instrument that can be used for general purpose frequency measurement. The M1 has much greater sensitivity than ordinary frequency counters, especially at RF frequencies. This makes the M1 ideal for measuring radio signals off the air at the maximum possible distances using an optional antenna. For in-circuit measurement of frequencies from oscillators or test points, the 1 Meg input impedance amplifier can be used with a scope probe for direct connection.

The microprocessor digitally filters the RF signal frequencies to reduce spurious counting. All of this is done without relying on the signal strength to exceed some arbitrary level, ensuring reliable performance in today's dense signal environments. A proprietary algorithm monitors the incoming RF for stable coherent signals, and only when these conditions are satisfied will the count be presented to the user. Internal memory allows the M1 to store the last three filtered frequencies for later examination. This feature allows for unattended operation.

Digital Communications Port The M1 is equipped with a TTL asynchronous serial interface which allow the units to be connected to a personal computer for the purpose of reading frequency information. The three-wire interface is accessible via a 1/8th inch stereo phone jack. The OptoLinx is required to convert the TTL signals to RS-232C levels compatible with most personal computers.

• Digital filter mode greatly reduces the display of random noise and oscillation
• Digital auto capture locks counter display on first reading to pass the filter
• ARM/STORE button stores and recalls frequencies from a three register stack
• Low Power Consumption, 4-5 hour battery operation.
• Digital communications port
• Full range counter covers 10Hz to 2.8 GHz
• Ultra sensitive bargraph with 16 segment display of RF signal strength
• Built in RS-232C
• Multi-Function Counter with Frequency, Period, Ratio, and Time Interval Measurement Capability

Antennas - Maximize performance for a particular band.
Filters      - Eliminate unwanted signals outside the desired band.

Input Amplifier           
Impedance                 1 Meg Ohm input: 30 pF  
                          50    Ohm input: vswr <2:1
Range                     1 Meg Ohm input: 10Hz - 50MHz 
                          50    Ohm input: 10MHz - 2.8GHz
Sensitivity (Typical)     1 Meg Ohm input: <20mV 1KHz-10MHz
                                           <50mV 10MHz-50MHz
                          50    Ohm input: <10mV @ 10MHz
                                           <1mV @ 150MHz
                                           <5mV @ 800MHz
                                           <20mV @ 1GHz
                                           <100mV @ 2.4GHz
Maximum Input             1 Meg Ohm input: 50V AC + DC
                          50    Ohm input: +15dBm, 50 milliwatts
Time Between
Measurements              13 milliseconds, all range & gate times
RF signal
Strength Bargraph         16 segments, approximately 3 dB
                          segments. Relative indication
                          only. No calibration. Active when 50 ohm
                          amplifier is selected
Size                      4.9" High x 2.8" Wide x 1.4" Deep
Power                     9 VDC, 150 mA using model AC90 wall plug adapter.
                          5+ hours operation from internal 4 cell NiCad pack. 
                          16 hour recharge from AC adapter charger.
                          13.8V automotive source must be reduced to <10V
                          to prevent overcharge and overheating of M1.