Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would
be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate
that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views.
It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if
you would like to post something on RF Cafe's
page, please do.
Below are all of the forum threads, including all
the responses to the original posts.
Post subject: Analog Meters for sale
Posted: Tue Aug 21, 2007 10:09 am
Joined: Mon Apr 10, 2006
I have the following analog meters for
sale. These meters have been in storage for the past
couple of years. When they were removed from service they
were all working.
Weston Wattmeter Model 432
Quantity of 1 $25.00
Weston Model 264 0 to +/- 50 mA
Quantity of 3 $20.00
Weston Model 264 0 to +/- 100 mA
Quantity of 1 $20.00
Weston 0 to 150 V AC Quantity
of 1 $20.00
Weston 0 to +/- 30 uA Quantity of 1 $20.00
Weston 310 0 to 10V Quantity of 1 $10.00
Western Electric 0 to 1 mA Quantity of 1 $5.00
Knight 0 to 1 mA Quantity of 4 $5.00
Knight 0 to 5 A
Quantity of 3 $5.00
Simpson 0 to 50 uA Quantity of
Simpson 0 to 1 mA Quantity of 6 $5.00
Simpson 0 to 20 mA Quantity of 1 $5.00
Simpson 0 to
100 mA Quantity of 2 $5.00
Simpson 0 to 150 mA
Quantity of 2 $5.00
Simpson 0 to 3 A Quantity of 3
(this meter is marked AC) $5.00
Simpson 0 to 5 A
Quantity of 3 $5.00
Simpson 0 to 10 A Quantity of 1
Triplet 420-G 0 to 1 mA Quantity of 3 $5.00
Triplet 420-G 0 to 1 A Quantity of 1 $5.00
420-G 0 to 500 mA Quantity of 5 $5.00
Electrical Instrument 15V Quantity of 1 $5.00
anyone is interested I can send a digital picture of the
meter. Buyer will pay for shipping.
Post subject: Meters
Posted: Wed Aug 22, 2007 10:03 am
Joined: Tue Dec 26, 2006
"private messaging is disabled on this board" so I cannot
send an email to
a l a
s.c o m
There is one
on that list I definitely want.
posted in a manner that makes it tough for the spambots to
I have a 'broken' HP 425A that reads
down to +/-10 pA DC full scale.
The HV filter cap went
and killed the supply. Sure wish I had a schematic for it.
Back whenever that was made they called it
micromicroamperes. The smallest division on the meter is
0.2 pA To read this small of a current it uses a chopper
amp. The 'chopper amplifier' is literally a small motor
turning a disc with holes in it. #12 lamps on one side and
photocells on the other. I wish they had these things in
college. When it worked I showed other engineers that if
you just grabbed a couple of 'test leads' out of a drawer
and 'shorted them' you would read several pA at room
temperature and the current would change when I exhaled on
the 'shorted' leads. Using a meter that reads that low
requires very careful choice of conductors and connectors.