Here's a Heathkit IM-17 Volt-Ohm Meter I built when I was in high school, around 1973. It originally required a C cell and a 8.4V Mercury battery (no longer available) so I modified it for a standard 9V alkaline. Recently re-aligned it and put it back into service.

Nice old meter. I still have the Heathkit VTVM that I built in 8th or 9th grade. I should dig it out and get it working.

- Pete

My brother has two Heath VTVM's (different models) and their manuals. Both need tending to, but ought to be serviceable meters.

VERY cool!

I agree with Walker, very cool. I like using older test equipment too. It's just kinda neat. :thmbsp:

Here's a Heathkit IM-17 Volt-Ohm Meter I built when I was in high school, around 1973. It originally required a C cell and a 8.4V Mercury battery (no longer available) so I modified it for a standard 9V alkaline. Recently re-aligned it and put it back into service.

Did you have to make any circuit changes to use the 9V battery?

The weak point on those analog meters is the meter movement itself.

Fred

Did you have to make any circuit changes to use the 9V battery?

Nope. Just readjusted the bias pot and I was good to go.

Way back when I was 13 or 14 ..I loved Heathkits..http://www.audiokarma.org/forums/showpost.php?p=1449215&postcount=6

Nope. Just readjusted the bias pot and I was good to go.

If you want to maintain the original voltage, use a silicon diode in series with the battery.

The 0,6 Volts diode drop will bring the 9 Volts, precisely to the 8,4Volts original voltage...

If you want to maintain the original voltage, use a silicon diode in series with the battery.

The 0,6 Volts diode drop will bring the 9 Volts, precisely to the 8,4Volts original voltage...

Thanks, good to know and very easy to do. :yes: