Electronics Forum / Equipment / November 2005

I m working in a student project(Voip).
i want to know all the details of how a-law/mu-law compression
techniques works??(at the bit level).
it will be better if you provide an example which will make the idea

Who has a screen dump program for HP8569B for Windows ?
Thanks, Dix

I have several "older" instruments, acquired through ebay. They all
can plot via their GPIB bus. I gather it is possible to run software
on a PC that emulates a HP plotter, and so capture the result.
What are the current recommended GPIB cards to do this? The "standard"

In order to debug echo cancellation and DTMF keys, I need to record
phone signals.
In my first attempt, I purchased an inexpensive adaptor, but the
recorded audio has very poor quality.  I am guessing that the cause is

I've purchased a 20MHz Dual Trace Oscilloscope (see previous thread called
"Opinions on Oscilloscopes") and it's been quite fruitful so far.  Thanks to
all who helped me make a decision.
I've been working on low voltage circuits, and building simple rectifiers.

I have a puls generator mentioned above.
The settings for the impuls frequency and width and so
on work fine but there is a problem.
If I set the the impedance on 10kOhms I

I'm looking for a portable device (possibly a microprocessor, on the
scale of an inch or two but I'll take what I can get) which can sense
multiple analog voltages on the order of millivolts. Preferably this
device would have many channels (over 10). I'm looking to couple this

Apparently there is an issue with a defective chip in cameras, camcorders
and handheld computers. The chip is used in a variety of brands and products
and seems to have problems with humid or hot environments causing it to
fail. If you check out

I have a reasonably modern charger (a few months old) and some old
rechargeable cells (about 5 years old).  Is it wise to use the two
together?
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Service manual anyone?  Powers up but permanent display of 12.0002 which is
obviously an error code/indication of ADC failure or similar.
Thanks in advance

I have a set of one sender (led) and one retriever (phototransistor) from a
disassembled old printer.
The phototransistor is quite similar to
http://www.allproducts.com.tw/manufacture1/everlight/p18-s.jpg the left one

Hello everyone.  This is my first time posting to this group.   I have
a 496P that I picked up on eBay and of course, it is not functioning.
I have the four manuals for it, however the two service manuals do not
match and both do not match the actual unit.  This unit appears to be a

I have the problem with PM3070.
I have no the schematic and the PCB drawing from A3 block XYZ-Amplifier UNIT
(A3).
Can I ask You, who can help me to repair that board?

Sorry If I am asking dumb questions, I am trying to get a leg up on
(new to me) technology in the repair field.  My background is computer
programming but Tesla has been my hero since I was young if that helps
any! Currently I am reading through some books to learn this technology

So I bought a Sencore SC3100 scope on ebay and it didn't come with a
probe. I admit I got caught up with a little auction frenzy and should
have checked into the probe thing first. Do you need a special probe
for these things?  Or can you use any scope probe?  If any of you know