MessageView 421F schematic

dwfox1977@gmail.com wrote:
Could someone please help me locate a voltmeter, low cost, that will
detect a voltage pulse less than 120ms in length and about 120mV (give
or take 30mV) amplitude? All I really need it to do is flash an LED
when a pulse is detected. I do not need to know the voltage, period,
etc.. I only need to know that a pulse was detected. I am having
trouble finding the equipment through digikey, etc..
Click to expand...
Have you tried looking for a Logic Probe?

Good luck.

John
 
You probably altered the setting of the variable capacitor
inside the probe handle. That's the little screwdriver slot
made from plastic set into the side of the probe. Use the
calibrator signal to adjust for a nice square wave.

Many people don't know how to do this, so all of their AC
measurements are inaccurate.

Chris

nbritton@nbritton.org wrote:

Hello all,

I just got my first oscilloscope today, a Tek 2213, off ebay and was
playing with it most of the day using ether the probe adjust signal or
signals from my computer's sound card. The square waves from the probe
adjust where square and the sine, square, sawtooth, etc. waves from my
computer where as they should be too, everything was working fine!

Then... I decided I wanted to clean the unit...
The first thing I do is take off the pouch bag on top by removing the
two screws that hold the plastic back piece on, one more screw later I
had the blue case off to look inside the unit. I got the case back on
and then give the front panel a rub down with isopropyl alcohol and
Qtips. After fully dismantling the probe I did the same to it, the
probe is a "Tek p6006 BNC 3.5 / 10x = 7pf. 10M-Ohms"

After I get everything back together and turned the unit on I tested it
with the probe adjust signal, the square wave was not square, It has a
triangular spike at the top / beginning of the wave and the inverse at
the end / bottom of the wave. I switched the probe to the other
channel... same thing... test it with my PC... only thing that looks
normal is the sine wave*. After all that I connect another probe that
came with the unit, an old looking and worn out RCA WG401A. Everything
seems to be ok again.

What did I break???

*sorry forgot, If I remember right... I can flip the switch from AC to
DC that's on the vertical mode panel and the wave becomes (more) square.
Click to expand...
 
Chris Jones <lugnut808@yahoo.com> wrote in
news:117nqgvqbsk572a@corp.supernews.com:

You probably altered the setting of the variable capacitor
inside the probe handle. That's the little screwdriver slot
made from plastic set into the side of the probe. Use the
calibrator signal to adjust for a nice square wave.

Many people don't know how to do this, so all of their AC
measurements are inaccurate.
Click to expand...

No,his probe is an older model from tube scope days,that uses the probe
body to adjust compensation,then lock another threaded collar against it to
retain the setting.

--
Jim Yanik
jyanik
at
kua.net
 
seattle dave wrote:
I want to cause static or interference on a line that leads from
the wall to a callmaster IV made by Lucent. These are phones used in
call-centers... The line has eight wires and I think it is the same as

a computer data line?? There is no other power source to the Lucent
callmaster, so one of the wires must carry power. The wires are all
small however... It is the same cord as is attached to a computer modem

to a computer....


thanks for any help on this...


would a strong radio signal interfer??

You might want to review applicable law first.
Click to expand...

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
 
The carbonbased lifeform lisa429joy@aol.com inspired
sci.electronics.equipment with:
I am sure that this subject has been brought up before but is there a
way to make your own high frequency noise to stop annoying dogs from
barking.
Click to expand...
Fire up the BBQ, make sure it's stabile.
Wait till it's really ready to cook.
Put your pants down, take a deep breath and set yourself on the grill.

I'll bet that'll shut them doggies up!

Sorry, couldn't resist :).

My serious answer: I don't think any sound does what you want, no matter
how high or loud, it'll only make 'm bark louder probably.
There are collars with an electronic "ignition" that reacts when a it
detects barking, but that needs the owners to be equally annoyed as you
are (unless you are the owner of course).

Theo
--
theo at van-werkhoven.nl ICQ:277217131 SuSE Linux
linuxcounter.org: 99872 Jabber:muadib at jabber.xs4all.nl AMD XP2100+ 512MB
"ik _heb_ niets tegen Microsoft, ik heb iets tegen
de uitwassen *van* Microsoft"
 
In article <1116031464.618086.236490@f14g2000cwb.googlegroups.com>,
lisa429joy@aol.com says...

I am sure that this subject has been brought up before but is there a
way to make your own high frequency noise to stop annoying dogs from
barking.
Click to expand...
Actually, generating such noises are MORE likely to start barking
behavior.

There are other (and better) ways to deal with barking than
abusing the animal involved.


--
Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute.
(Known to some as Bruce Lane, ARS KC7GR,
kyrrin (a/t) bluefeathertech[d=o=t]calm -- www.bluefeathertech.com
"If Salvador Dali had owned a computer, would it have been equipped
with surreal ports?"
 
In article <1115509612.552450.80070@z14g2000cwz.googlegroups.com>,
seattlemanila@comcast.net says...

I want to cause static or interference on a line that leads from
the wall to a callmaster IV made by Lucent. These are phones used in
call-centers... The line has eight wires and I think it is the same as
Click to expand...
(1) Locate a Tesla coil and a galvanized tub filled with warm salt
water.

(2) Step into tub, take firm hold of the output end of the Tesla
coil with one hand.

(3) Flip coil power switch to 'On' with your free hand.

This should provide a great deal of static. However, I don't think
much of it would leak into the phone lines.


--
Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute.
(Known to some as Bruce Lane, ARS KC7GR,
kyrrin (a/t) bluefeathertech[d=o=t]calm -- www.bluefeathertech.com
"If Salvador Dali had owned a computer, would it have been equipped
with surreal ports?"
 
I too am in need of a manual, can anyone help? I would be most grateful
 
"teletech" <data@engineer.com> wrote in message
news:1115855539.326733.21590@g14g2000cwa.googlegroups.com...
After you review the applicable laws, you could learn alot here.
http://www.textfiles.com/phreak/BOXES/
Look for the Noise colored box.
Click to expand...
If you actually _believe_ what those phone phreaking 'manuals' tell you,
then you're a poor excuse for a 'teletech'.
 
Not specifically barking dogs but very interesting.

http://www.ratbehavior.org/rathearing.htm#UltrasonicPestRepellers
 
edavid3001@gmail.com wrote:
These circuits are in a closed box and include a badge card reader, a
RS485 -> RS232 chip, various specialized computer chips, a lamp rated
at 50HZ, several relays including Omron MY2 220/240VAC (S) and a row of
other relays that I cannot identify, a pizzo for sound, several circuit
breakers, and a Telemecanique ABL7 RM1202 power converter that takes
100-240VAC and turns it into 12VDC.

Obviously the DC circuits are not a problem, but my concern is the
relays, and other potentially frequency sensitive parts. The AC input
junction directly feeds to several of these circuits.
Click to expand...
Check the relays. Most relays I've seen say 50/60Hz. The lamp is not a
problem.
What other parts is there that feeds from AC?
I guess it'd work fine with 60Hz... Inductances will get less power at
60Hz, since the frequency is higher, but minimal difference. So you
won't burn anything I guess.

And the power converter takes 110VAC and turns into 12VDC, so it should
be fine with 110VAC.


--
MVH,
Vidar

www.bitsex.net
 
In article <1116944823.932906.305250@z14g2000cwz.googlegroups.com>,
edavid3001@gmail.com wrote:

I have an automatic wash bay that is being shipped in from Italy. I've
received the custom computer circuits already for testing, and they are
powered at 230V 50HZ and draw ~1A X 2 devices.
Click to expand...
Edwin-

In most cases, equipment designed for 50 Hz should work at 60 Hz with no
problem. The trouble occurs when going the other way. A 60 Hz
transformer or relay coil may draw more current when fed with 50 Hz power
because they have less iron and/or less wire in them.

However, the relays might be part of a voltage-sensing system that
automatically switches the setup between 120 and 240 Volts. If so, a 240
Volt 50 Hz relay might respond to 120 Volts 60 Hz when it shouldn't.

The equipment you describe sounds like something that would be used in an
industrial setting. If you have a plant electrician or engineer to set up
the equipment, they should be able to provide the necessary power feed.
One thing to consider is using 240 Volts instead of 120, since the 120
Volts is normally half of a 240 circuit.

Fred
 
kroger@princeton.edu wrote:

Hello, I do eeg research (brainwaves). Signals are on the order of
10 microvolts (millionths of a volt). I need a battery powered
instrument to measure noise in my environment on the same order.
The Vellemans, Flukes, Teks, and so on I've looked at only get down to
.1 mV or 30 microvolts (Velleman 230). This won't do.

1 - does anybody know of a more sensitive, battery powered instrumcnt?
2 - could I build/buy some sort of battery powered amp or preamp for
the noise I pick up with an antenna?
(was thinking about a 9v guitar preamp)

Thanks in advance for any help....

Jim

Almost any operational amplifier will do the job.
Click to expand...
And you can add simple filtering: capacitive coupling to the
feed-forward resistor for the low end, and a shunt capacitor across the
feedback resistor for the high end.
I did that with a uA709 ages ago for a bio-feedback "machine" that
fit ina pocket and ran from a 9V battery.
 
Why would anyone "test" a URL that might be or have a *nasty* virus???
 
Ken,

Good luck on that one. I'm in desperate need of an owners and service manual
for a Wavetek 2520 as well, and haven't had any luck as yet. If you find
a source, please keep me in mind.

Don W.

ken.grant@uhn.on.ca wrote:

Hi. I'm in desperate need of the service manual for a Wavetek 2510A
signal generator. All of the sources on the Big List have come up
empty. I'd be willing to pay copying expenses if anyone can help. This
equipment is owned by a publicly-owned cancer treatment and research
centre. Thanks for any help. Ken
Click to expand...
 
"keithcc" <keith.cc@charter.net> wrote in
news:1117486102.442457.21620@o13g2000cwo.googlegroups.com:

I just bought a tek 465 scope on ebay, but am having a problem with it.
For about half the time, everything works fine, but occasionally, and
for no apparent reason, the scope will behave as if there is no
incoming signal on either channel - time/div, horizontal position,
intensity, etc can be changed, but vertical position cannot be, and
nothing will display on the crt when a signal is applied to either
channel. During such periods, setting A Trigger Source to a channel and
then pressing the trig view button correctly displays the signal on
that channel. Furthermore, and perhaps irrelevantly, the AC/GND/DC
selector below CH 1's volts/div knob doesn't click like CH 2's
does.
Click to expand...
You may have lost a roller bearing on the AC/DC/GND switch,or the lever has
loosened on the switch shaft.

The problem seems like it might be minor - a loose connection somewhere
- since at times the scope functions exactly as it should. any
suggestions as to what could be wrong are very much appreciated - i
don't have much experience with scopes, and certianly not with
troubleshooting them. I also don't have a service manual yet, but am
trying to find one on ebay. Thanks.
Click to expand...
Maybe a bad trigger view/BW limit switch on the vertical pre-amp board.It's
towards the rear of the PCB,near the delay line connection.It's heat-staked
on,and has HF cam switch contacts that have a very low wiping force,and are
suceptible to contamination,like films from plastics outgassing,cig
smoke,dirt.

At TEK,we used to remove the plastic sw.frame,tear off the old
contacts,bolt on new ones from a repair kit,and stake on a new
sw.frame.Those parts are no longer available.

So,what you do is take a narrow strip of paper,slide it under a closed
contact,and put a drop of 90% isopropyl alcohol on the paper,and carefully
slide it back and forth to clean the contact and the PCB pad.If the
contacts have lost tension,then you have to scavenge some from a parts
board.

--
Jim Yanik
jyanik
at
kua.net
 
Ken,

Thanks. I contacted them, and should be able to get a copy of the manual.

Good luck with your 2510A. BTW, I've got a flyer for the 2520, and it lists
the 2520 as the 2520/2510A, so you might find that most of the functions work
the same. I think that the 2520 just has an extended frequency range.

Don W.

ken.grant@uhn.on.ca wrote:

Don,

This fellow has an operator's manual for your 2520:
http://www.yourmanualsource.com/ We need a Hen's Teeth Test Equipment
group :)

Ken

Don W wrote:

Ken,

Good luck on that one. I'm in desperate need of an owners and service manual
for a Wavetek 2520 as well, and haven't had any luck as yet. If you find
a source, please keep me in mind.

Don W.

ken.grant@uhn.on.ca wrote:


Hi. I'm in desperate need of the service manual for a Wavetek 2510A
signal generator. All of the sources on the Big List have come up
empty. I'd be willing to pay copying expenses if anyone can help. This
equipment is owned by a publicly-owned cancer treatment and research
centre. Thanks for any help. Ken
Click to expand...
 
admin wrote:

Search on Six-Port Calibration techniques, a la
http://www.measurement.sk/2004/S3/Urbanec.pdf
Glenn


Can somone give me some info about:

Measurement of the absolute value of the complex impedance using
scalar detectors. I mean detectors which can measure
magnitude/power/RMS but not phase
of the sine wave.

Thank you!
admin
Click to expand...
 
In article <1118091823.471227.24610@g49g2000cwa.googlegroups.com>,
pdmtr@yahoo.com says...
Anyone know something about that problem? I cant find even the manual
of the HP 8567A spectrum analyzer (while i have found where to buy the
manual for the 8568A/B model), so any help will be greatly appreciated.
My regards
Sotris Pdmtr
pdmtr@NOSPAMyahoo.com
Click to expand...
I believe the 8567A was simply a reduced-cost version of the 8568A. It
is probably OK to use the 8568A's manuals to troubleshoot it.

I am about to start tracking down the same symptom on an 8566B, so we'll
have to wish each other luck! (That's a pretty-different machine,
though.)

-- john KE5FX

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------
 
In article <1118106580.241815.130950@o13g2000cwo.googlegroups.com>,
kb6lue@pacbell.net says...
Looking for a copy of the service manual for the Rohde & Schwarz ESH3
Test Receeiver.
Click to expand...
Try Telford Electronics (www.telford-electronics.com) in the UK. They
recently supplied me with a reprinted manual set for an R&S ESM 500A for
a lot less than I expected to pay. They seem to be nice people to deal
with.

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------
 
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