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