HP-4352B: quick peek inside

The HP-4352B is a strange instrument with a strange name: VCO/PLL signal analyzer. For a strange instrument it can be found quite frequently on auction sites and can be had for a song, especially compared to other more usable instruments of the same form factor and origin like the HP-4396B and HP-4395A, among others. All were designed in Japan and share the same chassis and many other components like display or motherboard. And this is the reason why this instrument is on my bench today: my HP4396B has a bad display and it is actually cheaper to buy a full 4352B than to get a second hand LCD from China. So the plan is to swap the LCDs between the two instruments and sell the 4352B as parts.

The 4352B before its demise. Nice LCD though :-)

Starting from the bottom panel we can uncover the main board and some RF components. The most recent date code on the chips (and thus the closest to its manufacture) is 1999, week 48. This device was thus very likely assembled at beginning of the year 2000.

The main board of the 4352B is the same part number as what is found in the 4396B.

The rest of the underside and its RF bits

Detail of the RF plumbing.

The top part is where all the 'cards' reside: power supply, display board and RF modules:

All the cards and modules on the top side of the instrument

The RF cards and modules on the top side

The last pic for this teardown is a low-quality replacement job for the front rotary encoder/dial. The original HP part is gone and has been replaced by a more generic part. Good to know, because the HP part is definitely unobtainiun after 25 years...

The cables are pretty ugly but hey it works I guess...

That's all folks! For more about the display and the GPU board check out the HP4396B page.