Electronics Forum / Equipment / February 2005

I am looking for (2) Philbrick K2-W gray base, dual-triode, op-amp
modules for my collection, with or without tubes. Original box & data
sheet a huge plus but raw units OK. Also looking for Philbrick amber
base tube chopper modules, black potted solid-state op-amps from

I am looking for a manual on a B+K Precision 830 Autoranging
Capacitance Meter.  I didn't see any on BAMA.  Found one on the web
for $17, but seeing as how this device only has two switches and a
knob, I don't think there's $17 worth of info in the manual.

Hello every one, Can i measure the continuous variation(with frequency
above 10 kHz) in the capacitance and dielectric constant of a fine
capacitor with capacitance meters or LCR's? Please introduce me a web
link for these instruments.

I just bought a 115VAC HP4261A without a manual.
I need to set the mains power entry to 230VAC.
Does anyone have a manual?
I need a copy of the page that describes how to do this.

I am in the UK (so mains voltage is about 230V or 240V).
I have a reel of main extension cable made of 3-core 1.0 mm^2 wire
rated at 10 Amps.  So the nominal power rating would be about 2,400
Watts.  (Link to tech reference for the cable is below.)

Any suggestions for common faults.
Sampling probe diodes seem OK but bias volts seem asymmetric  all lights
work but no sign of synchronisation.

my scope show test 04 fail 10
J'm looking for schematic for this scope ( J have manual without diagram
schematic )
probably scope need calibration or someting is damaged with memory

Well, didn't get the ones on Ebay, so anyone got one to sell?

Hi , having a 12-Cell Lithium Ion Battery that goes on a NEC laptop.
The battery doesn't keep the charge for a long time. Are they repairable ?

For any hobbyists/hams who are interested, I have a mostly working,
mostly intact Heath IO-18 oscilliscope available for pick-up.  Give it
to your kids to play with, use it as a station monitor, I don't care, I
just want it to get some use in a good home.

Many of you may have opened a computer mouse and have seen two slotted
wheels which rotates in one or another direction depending on how you
move the mouse.. (I am talking about an ordinary rolling ball mouse)
I was wondering how the bidirectional motion of these wheels are

Has someone of you experience how a high precision multimeter is constructed
?
e.g.: http://www.home.agilent.com/USeng/nav/-11250.536881781/pd.html
How is the voltage reference stabilized? (by using an oven?)

I have come upon a large batch of Solitron Microwave coaxial
connectors of a type which I don't recognize. They are Solitron
Microwave part # 4503-0006, fully gold plated, and appear to be
intended for soldering to rigid or semi-rigid coax.

Could you please recommend a book that would teach me the basics of RS-485
and RS-422 ?  I have been in the library, using the computer to attempt to
find a book with RS-485 (or RS485, RS-422, RS422) in its title, but without
success. When I searched for "data communications" ...

I posted this to a few different newsgroups, sorry for the triple postings,
I wasn't sure of the most appropriate place to post.
Since I can't find anything on the 'net that will test them, I am
considering building a RAM tester, specifically a 4116 DRAM tester.  It is a