[Boatanchors] VTVM QUESTION

[Dave Brown]

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
>
> _______________________________________________
> Boatanchors mailing list
> Boatanchors at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/boatanchors
> ** List Administrator - Duane Fischer, W8DBF/W9WZE **
> ** For Assistance: dfischer at usol.com **
> $$ For vintage radio info, see the HCI web site $$
> http://www.w9wze.org
>
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.375 / Virus Database: 267.15.0/249 - Release Date: 
> 2/02/2006
>
> 



-- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.375 / Virus Database: 267.15.0/249 - Release Date: 2/02/2006