Re: Warm up time on old capacitor checker

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> 

That green eye is a vacuum tube (sort of like a crude CRT), with a filament
that needs to warm up.
The other circuitry in the instrument is probably also vacuum tubes, and
needs to warm up.

10min seems a bit long before it , but I would expect that it could take
20-30 minutes to reach thermal equilibrium and have stable readings.


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, December 20, 2003 7:31 AM
Subject: Warm up time on old capacitor checker


 > Original poster: "John Richardson" <jprich-at-up-dot-net>
 >
 > Hi,
 >
 > This is directed to a few of the old timers out there.  I have an old
 > hamfest Heathkit capacitor checker, and was doing some MMC readings last
 > night.  It didn't even want to register anything on the green eye until it
 > warmed up for at least ten minutes!  Is this normal for these things?  I'm
 > used to new stuff, where results are instantaneous in this solid state
age.
 > Each of my 942 series caps measured out at .15 on this old thing, and a
 > string of 7 measured about .02, even though it should be about .0143.  Do
 > you think that this is accurate, or is my "Ten Minutes to Warm Up
Heathkit"
 > off a little bit?  I'm not disappointed if it is, as it was only fifty
 > cents.  One more question, since this is directed at the old timers:  How
 > old is our oldest list member?  I recall John Couture mentioning that he
 > turned eighty five this last year.  It amazes me that the demographics of
 > this hobby are so wide.
 >
 > Thanks,
 > John Richardson
 >
 >