Things You'll Need
Instructions
Plug the 1804D frequency counter and audio oscillator into standard electrical outlets. Connect the audio oscillator to the frequency counter with the 3-foot BNC cable. Use the HF BNC input on the frequency counter. Make sure the HF/VHF and gate time switches are in the out position. Turn the oscillator on and press the frequency counter's front panel power switch.
Turn the oscillator's frequency control up and down and note the frequencies shown on the 1804D's LED display. The display should update 10 times a second. Leave the frequency control alone for a minute and note that the first digit of the counter occasionally changes by one or two counts. If the oscillator is stable, the higher digits should remain constant. Press the gate time switch. Note that the counter display now updates only once a second. If you change the oscillator's frequency, the counter will take longer to settle on a stable reading. Set the gate time switch to .1 second if you need to follow a rapidly changing frequency. Use the 1.0-second setting to measure very low audio frequencies. Turn the audio oscillator off and disconnect the BNC cable. Unplug the oscillator from the electrical outlet.
Connect the radio signal generator to the BNC cable. Connect the other end of the BNC cable to the 1804D's VHF BNC input. Press the HF/VHF gate switch in. Plug the radio signal generator into a power outlet and turn it on. If the radio signal generator has modulation features, make sure these are turned off so the generator produces a pure, steady signal. Turn the radio signal generator's frequency control knob up and down and note the frequencies shown on the LED display. Note that at VHF radio frequencies, the MHZ LED on the counter will light up. At lower frequencies, the MHZ LED will go out and the KHZ LED will turn on.