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Homemade Frequency Meter

Homemade frequency meters are available in kits like the Crowcroft 95. It is a 50 MHz 8 Digit Frequency Meter. The kit has numerous small signal diodes and metal film resistors that need careful attention to identify. It has multiple PC boards with helpful component overlays to assist construction. Simpler kits employ only a handful of components such as the Universal Frequency Meter. Try a simple counter useful for frequency measurements for transmitters, receivers and signal generators in the VHF/UHF band.

Homemade 1 GHz Counter (Frequency Meter)
- This simple counter measures frequency in wireless equipment such as transmitters, receivers and generators. It has a display range of 0,0 to 999,9 MHz with resolution down to 0,1 MHz. It features correct rounding, reduced blinking of the last digit and over-range indication. All measurements are fast with short measuring periods. High input sensitivity is exhibited in the VHF/UHF band. A switchable intermediate frequency offset is available for use with a receiver.
  
  Technical diagrams include a detailed schematic, a PC board with parts overlay and a color photo of the finished parts placement. There are 14 resistors, 22 capacitors, 3 Internal Circuits (ICs), 5 transistors, a red or green 4-digit multiplex-driven LED by HP, 1-4,000 MHz crystal, a BNC connector and a PC board. A note is given on IC2, which is a prescaler for UHF/VHF tuners. The circuit is an input amplifier with a divider and an output stage. The divider stage may oscillate under no-signal conditions, but this oscillation is stopped when input signals are received.
  
  Kit building is straight forward and should be a good challenge for the experienced DIY kit builder. Sort out metal-film resistors and identify prior to starting. If you have difficulty with the color coding, use an ohm meter to measure resistors and mark accordingly.

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