[Boatanchors] VTVM QUESTION

[k0dan]

Hi Dave...

Thanks for your reply. Well, I don't know much about this meter other than
that it has 3 probes: ground, DC, and AC (the AC probe is also used for
ohms). So, I was gonna just put a diode (not too big, not too small) inside
a probe handle and build my own. But I'm not sure how critical the specs are
in order to have an accurate reading on the meter. To me, a diode is a
diode, as long as current doesn't burn it out. I realize this is heresy for
to the engineers and lab dudes, but that's why I posted my question!   ;-)

Thanks and 73

Dan
K0DAN



----- Original Message -----
From: "Dave Brown" <tractorb at ihug.co.nz>
To: <boatanchors at mailman.qth.net>
Sent: Saturday, February 04, 2006 1:10 AM
Subject: Re: [Boatanchors] VTVM QUESTION


> Dan
> I don't know the WV77E but a lot of those early VTVMs didn't have an
> external recitifier type AC probe- some of the RCA ones had a combined
> AC/DC probe with a slide switch on it to short the internal resistor
> on the AC ranges.
> There was an add-on high frequency diode rectifier for this type of
> probe - it was in a housing that slipped over the front of the probe
> for RF work.
>
> But if the WV77E does use a separate AC rectifier type probe, I see no
> reason at all why a homebrew diode rectifier replacement probe
> shouldn't work-as long as you use a similar type of diode to the
> original so the existing AC meter scales can be used.
>
> 73
> Dave, ZL3FJ
>
> ----- Original Message -----
> From: "k0dan" <k0dan at comcast.net>
> To: <boatanchors at mailman.qth.net>
> Sent: Saturday, February 04, 2006 4:37 PM
> Subject: [Boatanchors] VTVM QUESTION
>
>
> > This might be a tad off topic, and if so I apologize in advance.
> >
> > I picked up an RCA Volt Ohmyst (WV77E) VTVM. No probes. Apparently
> > the
> > original AC probe has a diode built in but it's not spec'd in the
> > schematic
> > or manual I got off BAMA.
> >
> > Is there any reason I shouldn't build myself a probe with a junkbox
> > bullet
> > diode (1N5401, 1N4816, etc.)? If this requires a more spec-focused
> > approach,
> > what needs to be inside the probe?
> >
> > Thanks and 73
> >
> > Dan
> > K0DAN
> >
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