[R-390] Meter Question

[Mark Donaldson]

Barry,

I have already bought some of those meters from ATC
and the internal resistence is somewhere North of 1K
Ohm which means shunting will give you an internal
resistance arount 100 Ohms which is if memory serves
me about 10 times higher than what you want.

--- Barry <N4BUQ at aol.com> wrote:

> Gents,
> 
> The gentleman selling these sent me one with the
> front glass broken.  After
> receiving it, I realized it may be a
> "glow-in-the-dark" meter and could be
> hazardous.  It was sealed in a plastic bag and I put
> it in a glass jar with
> a tightly-fitting lid until I figure out what I'm
> going to do with it.
> 
>
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5717004917
> 
> I bought it because I wanted to measure the internal
> resistance in hopes
> that it might work as an R390A replacement.  The
> meter movement is fs=100uA
> so it would require some shunting at the very least;
> however, if the needle
> is painted with radium-based paint, then I don't
> want to fool with it.
> 
> Is anyone familiar with these and know if they are
> hazardous?  It has a
> "SEALED DO NOT OPEN" stamp and I thought that might
> be one clue that it
> might be a problem.
> 
> Yeah, I know the threat is minimal and as long as I
> don't lick the insides,
> I'll probably be okay, but I just really don't want
> to take the chance.
> 
> Thanks!
> 
> Barry - N4BUQ
> 
>
_____________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/faq.htm
> Post: mailto:R-390 at mailman.qth.net
> Unsubscribe:
> http://mailman.qth.net/mailman/options/r-390
> 



		
__________________________________ 
Yahoo! Mail for Mobile 
Take Yahoo! Mail with you! Check email on your mobile phone. 
http://mobile.yahoo.com/learn/mail