Hey, DaleReid,
I was cleaning out the garage and sorting boxes and ran across my aging copy of "The Amateur Scientist, Projects from The Scientific American" by C. L. Stong. it's a compilation of his SI columns from the 50s and 60s (publishing date on my copy is 1960).
I've been going through it, and marveling at some of the stuff he and his correspondents were doing back then (several seismographs, including one that uses a water well, "exploring the atom at home", "how to tranquilize a rat". "a universal sundial" and lots more.
In there is one article, "AN ELECTRONIC WEATHER FORECASTER" which turns out to be a sferics and electric field measuring device. It sounds like something you might be looking for.
With the exception of the electrical-pen recorder, the equip-
ment for measuring field intensity and making sferic counts is
relatively inexpensive. The sferic detector is essentially a special
radio receiver equipped with a means for counting short pulses
of current [see Fig. 119] The antenna consists of a bare copper
wire at least 20 feet long suspended 10 feet or more above the
ground between glass insulators. It serves the dual purpose of
picking up sferics and sensing field intensity.
A sferic signal excites the tuned 456-kilocycle transformer, and
the resulting oscillations are amplified. The train of amplified
oscillations is then rectified and used to trigger a pulse-forming
circuit. The output is averaged in a vacuum-tube voltmeter cir-
cuit. The antenna should be equipped with a lightning arrester;
as a further protection the receiver is equipped with a choke coil
designed to block damaging bursts of energy at high frequencies.
Here's the schematic, copied from a PDF of the book on-line. Note in the bottom left the meter for displaying the local field intensity.
It would be an interesting project to convert this from hollow state to solid state electronics.
If you are interested in the entire article, or perusing some of the other projects, the entire book can be downloaded free in various formats at
https://archive.org/details/TheAmateurScientist You may have to download it in more than one format to get everything. The PDF with text might be the best. The raw text version was missing some text.