Frequency Counters For Sale

HP 3735A

Digital Frequency Counter

This counter is in near perfect condition, and looks little used. It is in full working condition, and immaculate inside and out.

Solid state circuits, and nixi tubes which are perfect in operation.

Unfortunatly HP Oval power connector is not included with sale!



  • 12.5Mhz
  • 10mV rms
  • 6 digit nixi tube display (HP modular type)
  • Frequency
  • Period
  • Ratio
  • Time Interval


HP 3735A
HP3735 Brochure 1 HP 3735A Brochre 2
HP 3735A Brochure 3 HP 3735A Brochure 4


Racal Dana 9921

3 GHz Frequency Counter

Fitted with optional low frequency multiplier, which increases resolution to 5kHz by 100 times.

Case in good condition for age, but is missing the carry handle.

Fully working.


  • Nine LED digit display
  • Three inputs
10 Hz to 100Mhz
Max resolution 0.1Hz (0.001Hz to 5kHz)
Sensitivity 10mV to 70MHz, 50mV to 100MHz
Input Impedence 1Meg Ohm
Max input 10V RMS (400Vdc)
40MHz to 560MHz
Max resolution 0.1Hz
sensitivity 10mV
Input impedence 50 Ohm
Max input 35V rms (LED warning at 5V rms)
300MHz to 3GHz (3000MHz)
Max resolution 20Hz
Sensitivity 30mV rms
Input impedence 50 Ohm
Max input 2.25V rms, plus 100Vdc
  • Frequency Standard 04A (9442 OCXO)
  • Option 09 LF multiplier (100x increase in resolution 10Hz to 5KHz)



Racal 9921

Racal 9921


Systron Donner 6016 Microwave Frequency Counter

18GHz Frequency Counter (18,000,000,000Hz)

A Nice 1970's digital frequency counter for counting between 20 Hz and 18 GHz.

Nine nixi tube display, with fast, slow or hold display, with resolution to 100 Hz when measuring 18 GHz.

Fully working and accurate (can only test to 3GHz). I believe is fitted with a "Standard" oscillator, which has a 72 Hour warm up time, so tested using my 1MHz reference source)

(Marconi Signal source used to demonstrate, is not a precision source, using a cavity tunned gun diode)



  • 20 to 200Hz, with 1Hz to 1MHz resolution
  • Sensitivity 10mV rms
  • Impedence 1M Ohm with 20pF
  • 200MHz to 18GHz
  • Resolution 1Hz to 1MHz
  • Sensitivity -13dBm to -3dBm
  • Input impedance 50 Ohms
  • External reference 1MHz


Systron_Donner_6016 Systron_Donner_6016
Systron_Donner_6016 Systron_Donner_6016

HP 5300A / 5303B System UHF Frequency Counter
Quality HP UHF frequency counter from HP 5300 System

  • 525 MHz frequency range
  • Resolution down to 1Hz
  • 6 Digit
  • Two inputs, 0 to 80 MHz and to 525 MHz
  • Very sensitive
  • Strong metal cased instrument

This is a very nice Hewlett Packard system 5300 UHF frequency meter.
Can read up to 525 MHz with 1 Hz resolution (using overflow measurement)
It is in very good condition and performs very well. Relatively compact size, with nice clear LED dot display.

There is slight damage to the rear foot, but does not affect the stability of the instrument.

Shown sampling my hand held radio on 425.575Mhz through antenna coupling and low power.

Icom Radio is NOT included



HP 5300A 5303B
HP 5300AHP 5303B
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