A 1990s VNA Gets An LCD

A Vector Network Analyser, or VNA, is the ultimate multi-tool of RF test equipment. They can now be had in not very capable form for almost pocket money prices, but the professional-grade ones cost eye-watering sums. Enough to make an older VNA for a few hundred on eBay a steal, and [W3AXL] has just such a device in an HP 8714C. It’s the height of 1990s tech with a floppy drive and a green-screen CRT, but he’s homing right in on the VGA monitor port on the back. Time for a colour LCD upgrade!

There are two videos below the break, posted a year apart, because as we’re sure many of you will know, events have a habit of getting in the way of projects. In the first, we see the removal of the CRT module and safe extraction of its electronics, followed by the crafting of a display bezel for the LCD. Meanwhile, the second video deals with the VNA itself, extracting the VGA signal and routing it forward to the new module.

We’re struck not for the first time by the high quality of the construction in this piece of test equipment; it’s not only substantial but well designed for maintenance and disassembly. [W3AXL] sensibly leaves the RF part alone, but both CRT and mainboard modules slide out with minimal screw removals and few problems in reassembly.

He goes the extra mile with a second iteration of the display mount and a curved print to fit the CRT shape in the front panel. The result is a colour display on the instrument, and we’re guessing, a much lighter device, too.

If VNAs are new to you, then you might wish to learn a little about them,