# \#vtvm

**URL:** https://scanalyst.fourmilab.ch/tag/vtvm/5030.md

[Latest](https://scanalyst.fourmilab.ch/latest.md) · [Categories](https://scanalyst.fourmilab.ch/categories.md) · [Tags](https://scanalyst.fourmilab.ch/tags.md)

---

## [Building a New AC Probe for a Vacuum Tube Voltmeter](https://scanalyst.fourmilab.ch/t/building-a-new-ac-probe-for-a-vacuum-tube-voltmeter/4205)

<div class="topic-metadata">

**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [11 January 2024 13:06 UTC](https://scanalyst.fourmilab.ch/t/building-a-new-ac-probe-for-a-vacuum-tube-voltmeter/4205 "2024-01-11T13:06:10Z")

</div>

Having previously restored a Hewlett-Packard 410C Vacuum Tube Voltmeter, now it’s time to try to replace the missing piece, the active alternating current (AC) probe that allows it to measure voltage at fre…

---

## [Restoring a Vintage (and Abused) Hewlett-Packard 410C Vacuum Tube Voltmeter](https://scanalyst.fourmilab.ch/t/restoring-a-vintage-and-abused-hewlett-packard-410c-vacuum-tube-voltmeter/4033)

<div class="topic-metadata">

**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\
**Replies:** 0\
**Last updated:** [26 November 2023 15:40 UTC](https://scanalyst.fourmilab.ch/t/restoring-a-vintage-and-abused-hewlett-packard-410c-vacuum-tube-voltmeter/4033 "2023-11-26T15:40:50Z")

</div>

The Vacuum-Tube Voltmeter (VTVM) was a mainstay of electronics engineers and technicians’ benches for decades, but is now largely forgotten. Present-day instruments are lighter, easier to use, and more ver…