MessageView 421F schematic

[DAW]

What a dweeb. Use plutonium, you won't need as much.
"Karl-Hugo Weesberg" <netspider4@lycos.com> wrote in message
news:7666ed5f.0410261959.1868a43a@posting.google.com...
>I need it fast!

 

[Rich Webb]

On 7 Oct 2004 11:04:07 -0700, lrttest@yahoo.com (J Autt) wrote:

I am looking for a handheld Spectrum Analyzer BK2650 (Link1 below) or
Field Strength Analyzer Protek 3290 (Link2). The problem is that I
cannot see the major differences between them, yet there's a major
price difference of $1000-2000. Can anyone tell me what the major
differences between a spectrum analyzer and Field Strength Analyzer?
Is it in demodulation ways, sweep speed, display freq span, or some
extra stuff that I do not need as an amateur/electronics hobbyist?

Just curious (and I apologize for reincarnating a thread that's almost a
month old) but did you take the plunge on either of the instruments? I'm
tempted by the 3290 and wondered if you got it and what your thoughts
were.

--
Rich Webb Norfolk, VA

 

[Mark Zenier]

In article <RwWgd.808889$Gx4.207517@bgtnsc04-news.ops.worldnet.att.net>,
Norm Dresner <ndrez@att.net> wrote:

I need to set up a card rack with about 10 cards which will plug into 22/44
pin .156" edge connectors. I need a bus to connect these together. At
present I'm faced with
a) trying to fabricate a PC
b) finding and using wire-wrap connectors
c) hand-wiring "solder cup" connectors together

Obviously the best electrical solution is (a) but trying to create a board
that's 13+ inches long is going to severely tax my capabilities and it while
I could probably design it in EagleCAD and get someone to make up a small
lot of them, I'd much rather order one or two from a manufacturer who has a
variety of designs to choose from. But I haven't found anyone who's line
includes these bus boards. Have I missed something? If so, does anyone
have a URL or address/phone# for a place where I could purchase small
quantities of these. Ideally I'd like a selection of connector styles and
spacings but even having one or two choices would be a great advantage.

Er, 20 years ago, I'd say try Douglas or Vector. Or use STD bus hardware
which is the same card size but a 56? contact connector.

Mark Zenier mzenier@eskimo.com Washington State resident

 

[Fred McKenzie]

Lenny-

I wasn't able to respond to your October 17th posting until it had died of old
age!

You had a question about the panel meter which doubles as a voltage and current
indicator depending on the front panel push buttons. I remember a couple of
replies that may have been helpful, but may have missed the mark regarding
typical circuits used for such meters.

Take a look at the face of the meter movement. You will often find some small
print near the bottom of the scale, that indicates the meter's basic
sensitivity. For example, you might see "FS=50uA" or "FS=1mA". Such a marking
would indicate the meter movement was a current-sensing meter with a full scale
reading equal to the marked value.

When used to measure voltage, a meter movement usually has an external series
resistor, chosen so the full scale current flows when a particular voltage is
applied to the series combination. For example, take the case of a meter
movement with "FS=1mA". Such a voltmeter is said to have a sensitivity of 1000
Ohms per volt. If the total series resistance is 1000 Ohms, full scale
deflection will result from connecting a voltage of one volt. (A one
milliampere DC meter movement may have an internal series resistance of around
50 Ohms.)

There are two common ways to use such a meter movement to measure current. The
simplest is to connect a "shunt" resistor in parallel with the movement. When
the indicated current flows, the majority flows through the shunt, and only the
basic amount flows through the meter movement.

Another method is to use the series resistor to make a basic one volt
voltmeter, and measure the voltage across a larger value shunt resistor, so
that full-scale current is equal to one volt divided by the resistor value, or
resistance is equal to one volt divided by the full scale current. This
approach might be used to measure a transistor's emitter current by reading
voltage drop across its emitter resistor.

In either the voltage or the current case, switching the meter between circuits
should have little effect on the circuits being measured unless meter
resistances were low compared to the circuit resistances. With the above in
mind, you should be able to figure out what is going on with your power
supply's meter system. Your symptom of no meter reading might be simply a
defective meter, but you should be able to check that. Just don't connect a
voltage to it without a series resistor to limit the current to something less
than its sensitivity! I'd suggest starting with at least 100,000 Ohms if you
don't see a full scale value printed at the bottom of the meter face.

Fred

 

[Robert Baer]

Teddy Chiang wrote:

I wish use THS730A to measure two signal with about 160V ~ 200V
floating voltage. Does anyone knows that, will the THS730a be damaged,
if I don't use Tek's P5102 probes.

Please advise. Thanks!
Ted

For grounded test equipment, one should use two probes, one for the
high side, one for the low side, and measure the difference.
In this case, one could use a battery powered DVM (or scope) provided
safety precautions are met, the measuring instrument is insulated from
ground AND one does not touch the equipment when that power is on (!!!).

 

[Jim Yanik]

Robert Baer <robertbaer@earthlink.net> wrote in
news:418B43B5.9B481FFF@earthlink.net:

Teddy Chiang wrote:

I wish use THS730A to measure two signal with about 160V ~ 200V
floating voltage. Does anyone knows that, will the THS730a be damaged,
if I don't use Tek's P5102 probes.

Please advise. Thanks!
Ted

For grounded test equipment, one should use two probes, one for the
high side, one for the low side, and measure the difference.
In this case, one could use a battery powered DVM (or scope) provided
safety precautions are met, the measuring instrument is insulated from
ground AND one does not touch the equipment when that power is on (!!!).

The THS700s are battery-powered,insulated scopes.
I'd worry about potentials between each probe,though.

--
Jim Yanik
jyanik-at-kua.net

 

[Harvey White]

On Sun, 31 Oct 2004 07:33:26 -0500, "B. Joshua Rosen"
<bjrosen@polybus.com> wrote:

On Sat, 30 Oct 2004 09:06:49 -0700, Bob S. wrote:

Hello. Does anyone know were I can find the old BYTE magazine GPIB to
centronics printer interface article. (circa 1979 +/- 4 years)

Regards, Bob S.

Try a library, remember those. That's what we all used before Google.

You'd be surprised how little magazines are archived after 20 years or
so. If you're lucky, they might have the set on microfilm, but only
at the "central" branch.

Can be more difficult to find this stuff than you think.

Harvey

 

[ken]

Does anyone have a schematic or know where I can get one for an AB
MessageView 421F Thanks for any help, Ken

 

[ken]

Does anyone have a schematic or know where I can get one for an AB
MessageView 421F Thanks for any help, Ken

 

[TekMan]

Jim Yanik <jyanik@abuse.gov.> wrote in message news:<Xns95986373223CAjyanikkuanet@129.250.170.85>...

Robert Baer <robertbaer@earthlink.net> wrote in
news:418B43B5.9B481FFF@earthlink.net:

Teddy Chiang wrote:

I wish use THS730A to measure two signal with about 160V ~ 200V
floating voltage. Does anyone knows that, will the THS730a be damaged,
if I don't use Tek's P5102 probes.

Please advise. Thanks!
Ted

For grounded test equipment, one should use two probes, one for the
high side, one for the low side, and measure the difference.
In this case, one could use a battery powered DVM (or scope) provided
safety precautions are met, the measuring instrument is insulated from
ground AND one does not touch the equipment when that power is on (!!!).


The THS700s are battery-powered,insulated scopes.
I'd worry about potentials between each probe,though.

I'd worry too.

the Tek 222/222A/222PS had preamps with isolation barrier, seperate
for each of the channels. This technique easily allowd 500V diffrence
between both channels, and still save work (not too high humidity
conditions, of course).

The THS7xx uses a little bit different input technique, so I would not
risk going that high.

hth,
Andreas

 

[TekMan]

Jim Yanik <jyanik@abuse.gov.> wrote in message news:<Xns959E70DD79C94jyanikkuanet@129.250.170.86>...

and7@bigfoot.com (TekMan) wrote in
news:6a624601.0411102340.23ef2ceb@posting.google.com:

Jim Yanik <jyanik@abuse.gov.> wrote in message
news:<Xns95986373223CAjyanikkuanet@129.250.170.85>...
..snippety...

I'd worry too.

the Tek 222/222A/222PS had preamps with isolation barrier, seperate
for each of the channels. This technique easily allowd 500V diffrence
between both channels, and still save work (not too high humidity
conditions, of course).

The THS7xx uses a little bit different input technique, so I would not
risk going that high.

hth,
Andreas


Do you know of anyone with component-level schematics of the THS series
scopes?
I believe they're in the same category as TDS scope;no schematics in the
"service" manual.

No Jim, I am sorry: I don't know anyone. seems you are absolutely
right with your statement.

But I'll let the newsgroup know if I find schematics - may be someone
else who reads this has a contribution/donationof suc hschematics?
This would be real nice.

Andreas

 

[Teddy Chiang]

and7@bigfoot.com (TekMan) wrote in message news:<6a624601.0411102340.23ef2ceb@posting.google.com>...

The THS700s are battery-powered,insulated scopes.
I'd worry about potentials between each probe,though.

I'd worry too.

the Tek 222/222A/222PS had preamps with isolation barrier, seperate
for each of the channels. This technique easily allowd 500V diffrence
between both channels, and still save work (not too high humidity
conditions, of course).

The THS7xx uses a little bit different input technique, so I would not
risk going that high.

hth,
Andreas

Andreas,

Did you mean that the THS700 will be damaged if I don't use TEK's HV
probe(P5210) for common-mode voltage larger than 30V? Or it's just a
safety consideration for floating voltage?

 

[TekMan]

tedchiang999@yahoo.com (Teddy Chiang) wrote in message news:<93972683.0411131919.11e7211b@posting.google.com>...

and7@bigfoot.com (TekMan) wrote in message news:<6a624601.0411102340.23ef2ceb@posting.google.com>...
The THS700s are battery-powered,insulated scopes.
I'd worry about potentials between each probe,though.

I'd worry too.

the Tek 222/222A/222PS had preamps with isolation barrier, seperate
for each of the channels. This technique easily allowd 500V diffrence
between both channels, and still save work (not too high humidity
conditions, of course).

The THS7xx uses a little bit different input technique, so I would not
risk going that high.

hth,
Andreas

Andreas,

Did you mean that the THS700 will be damaged if I don't use TEK's HV
probe(P5210) for common-mode voltage larger than 30V? Or it's just a
safety consideration for floating voltage?

You have mentioned 160 V and higher in your first posting.
See the difference to mentioning now 30V?

well, to my opinion I ALWAYS would use a probe. Depending on the
floating voltage you have and the BW you need to measure: chosse the
P5210 or a simpler (not-HV) one - that's depending on your measurement
setup.


hth,
Andreas

 

[Robert Baer]

ghostwriter wrote:

Hello all,

Here is my set up, I have 8 photodetectors, I assume they are in fact
photoresistors but am not sure. I have not been able to get a
resistance measurment when I put a multimeter across it, but I get a
voltage when I touch both probes to the hot wire.

These photo-thingagigs connect to what I assume is a constant current
supply. As best I can figure the current supply corrects for noise in
the line(actually I use a knob on the front to correct for noise) and
as the resistance of the photoresisters change the voltage output of
the current supply changes to maintain a constant amperage. A data
logger captures the change in voltage and I use this data to analyase
and compare different samples. If it help this assumes that as the
light hitting the resistor decreases the resistance increases and
forces an increase in voltage.

Here of course is the kicker, this piece of equipment was cobbled
together by our field service group. Nobody here is willing to touch
the thing, and I am down to a single working photodetector. I dont
know if it is likley to be the current supply or the
photoresistors(assuming of course that they are photoresistors), or
for that matter the datalogger or the datacapture software.

My best guess is that I am using photoreistors and they have burnt out
due to time and use. Is this something anyone has seen before? And
since I have been unable to get a resistance reading off of the
working sensor, what am I missing? Is the resistance from a standard
photoresistor to low to measure with a multimeter, I wouldn't think
so, but God knows I have been wrong before.

Any help appreciated.

Ghostwriters

Well, i have been an electronic technician for over 50 years, and can
say that, for all practical purposed that you know almost nothing about
electronics or electronic components of any type.
At least someone pointed to one box and said "this is a power supply"
and the detectors and said "these aer photodectors".
And you have "dug into the guts" enough to be "dangerous".
From your description, i cannot say if you have photoresistors,
photodiodes, or some other tyoe of photo detector.
The same goes with the supply, except it is rare to find a constant
current supply in use.
The "nobody is willing to touch it" would seem to mean that they know
less than you do.
And if the equipment is slowly falling apart and there are no local
repair options in sight, then it would seem that you are beating a dead
horse.

You give no clues as to the use(es), sensitivities, spectral needs, or
any thing else of interest - except the hint that it has some kind of
data digitizing capabilities, which something else then reads, logs and
maybe analyzes (clue: software).
I most likely could fix it, and maybe even find a more reliable way to
do the same detection.
However, either trash it and get off-the-shelf equipment to do the
job, or forget the whole thing and let someone else "worry" about the
dead project (it is dead if the equipment is dead).

 

[artemesia]

We have just acquired a second-hand 16500A but have no manuals - do you
have an operators manual?

 

[Jim Yanik]

"George Kerber" <glkinst@earthlink.net> wrote in
news:OyUmd.3709$pK6.3106@newsread2.news.atl.earthlink.net:

Jim,
I cannot find any reference in the manual (and I have several
generations) that correlates cal step limit errors to specific circuit
malfuction or point of measurement that is out of spec. The only clues
for CAL 09 from the manual are that limit errors "are generally due to
A or B sweeps, A or B gates, or the measurements PAL" - this doen't
help much since all of the that seems to be working fine and only
steps 2 & 3 have limit errors. Regards,
George Kerber

You may have a bad sweep hybrid;the timing resistors and caps are on the
hybrid ICs.
You could try swapping A and B sweep hybrids and recal.

IIRC,"measurements PAL" is a programmed array logic IC on one of the
options.
(although it's been a long time.)

Do you have options installed,and what are they?


--
Jim Yanik
jyanik-at-kua.net

 

[Ed Price]

"Franc Zabkar" <fzabkar@optussnet.com.au> wrote in message
news:gpe0q09kudbgi47ps8n73usjcpgefiqn1o@4ax.com...

On Sat, 20 Nov 2004 10:22:40 -0800, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> put finger to keyboard and
composed:

SNIP

Please do us all a favour and report him for spamming the newsgroups.
I'd do it myself but the bastards at Ebay want me to register before
they'll allow me to complain.


- Franc Zabkar

Wouldn't you also complain and call them bastards if they allowed totally
anonymous complaints?

Ed
wb6wsn

 

[Robert Baer]

Like i mentioned on one of the other NGs that you have posted a number
of times, you have been reported.

 

[John Miles]

In article <41990264$1@proxy.>, ytreboe@adsl.no says...

Where cani find equipment that makes my laptop work as a signal generator
which makes it possible to simulate a crankshaft pickup signal . The
pickup detects
tooths on flywheel for the starter motor.
Ingvar
Norway.

I've written custom code to do this for ignition timing control with a
laptop. In my case, I used the parallel port to read the (conditioned)
signal from the crank sensor, forwarding it after an RPM-dependent delay
to the ignition module. It is not an especially-complex thing to do,
but I've never seen anything "off the shelf" with comparable
functionality that wasn't tied to specific engine-management hardware.

-- jm

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

 

[Rich Webb]

On Mon, 22 Nov 2004 01:16:29 GMT, Robert Baer <robertbaer@earthlink.net>
wrote:

Like i mentioned on one of the other NGs that you have posted a number
of times, you have been reported.

Submitting a TOS complaint to the originating ISP is a good idea; your
heart's in the right place. However, you do realize that the poster is
not likely to check replies in all of the thousands of newsgroups that
he spammed?

--
Rich Webb Norfolk, VA