In order to have better view (and better understanding) of how stuff works, especially in audio, I need to have more testing equipments. Unfortunately, those are quite expensive for a person who is doing this as hobby – like me. So one by one and step by step is the best way to acquire them.

One of them is below, HP/Agilent 5328A Universal Frequency Counter which covers up to 100 MHz. Not quite sure about the age of this device, but this device was introduced roughly on 1976 by HP, later taken over by Agilent. It has 8 digits (1+7) and mine also comes with nice Digital DC Voltmeter option.


The Digital DC Voltmeter (Option 021) installed on the front. Which should be able to handle up to 1100 VDC maximum. Option 021 has 0.03% and 0.004% reading/range of accuracy (better than Option 020). The input is floating with 10 MegaOhm impedance. You can’t be wrong with this option!

Also instead of coming with Channel A/B module, this one is coming with High Performance Universal Module (Option 040). It has 10ns single shot time interval, improved averaging, accuracy, delay measurement, A-B marker, hysteresis compensation, and switchable input impedance (1 MegaOhm or 50 Ohm).


Last but not least, it comes with Option 010 which is a High Stability Time Base.

It’s an Oven oscillator with aging rate <5 x 10-10/day, which is amazing.


The photo of the back side. There are some BNC ports which I still need to find out how to use them 😉


Need to spend some time to disassembly, clean it up, and then power it and do some initial basic calibration.