This page supplements our article that ran in the December 2012 issue of Electric
Radio, "The Poor Man's HP 410C VTVM." The article describes modifications to the
Heathkit IM-18 vacuum tube volt meter that allows it to use the Hewlett Packard
11036A wide range AC/RF probe.
Click on any picture to enlarge it
Click on any image on the left to view and download a full color full sized image of the
illustrations used in the article.
If you do decide to duplicate our poor man's HP 410C, here's how we mounted the meter
scale and new front panel labeling. We used Epson Presentation Matte finish paper on an
inkjet printer to print the meter scale and then glued it over the original Heath meter
scale. Similarly, we printed the new front panel on the same paper, protected it with
Krylon clear matte spray and then glued it over the original Heathkit front panel. In
both cases we used 3M Super 77 adhesive.
Feel free to use anything presented here for your own, non commercial purpose. The
Heathkit schematics presented here are with the permission of the copyright owner.
Our modified VTVM
Partial schematic
showing the original
"AC Function" Circuit
Partial schematic
showing the revised
"AC Function" Circuit
Full schematic of the
Heathkit IM-18 showing
the revisions made
Revised meter scale as
described in the article
Revised front panel lettering