MessageView 421F schematic

[Eric Smith]

Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> writes:

It's fairly common to break the corners off a monochrome LCD to allow
it to fit within a circular or elliptical outline. Cheaper than a true
circular outline.

I find that rather hard to believe. If you break the corners off, the
LC will leak out of the D.

 

[Spehro Pefhany]

On 21 Apr 2005 12:17:55 -0700, the renowned Eric Smith
<eric@brouhaha.com> wrote:

Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> writes:
It's fairly common to break the corners off a monochrome LCD to allow
it to fit within a circular or elliptical outline. Cheaper than a true
circular outline.

I find that rather hard to believe. If you break the corners off, the
LC will leak out of the D.

Yeah, okay, they break the corners off the glass *before* they
assemble and seal it.

It's was just intended as a description of the (irregular octagon)
shape of the LCD, not a description of the manufacturing process, wot?


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[John Woodgate]

I read in sci.electronics.design that Eric Smith <eric@brouhaha.com>
wrote (in <qh8y3cj5wc.fsf@ruckus.brouhaha.com&gt about 'A round shaped
LCD screen', on Thu, 21 Apr 2005:

Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> writes:
It's fairly common to break the corners off a monochrome LCD to allow
it to fit within a circular or elliptical outline. Cheaper than a true
circular outline.

I find that rather hard to believe. If you break the corners off, the
LC will leak out of the D.

..... and it's not particularly pleasant stuff. Luckily, there is not
much of it.
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Robert Baer]

mnowlen wrote:

FS: ELECTRONIC TEST EQUIPMENT:
Oscilloscopes / Analyzers / Oscillators / Signal Generators / AC
Voltmeters / Power Meters / VARIACs / Catalogs / More

Pictures available, please request.

CHECKED AND WORKING UNITS, 7 day right to return and a 30 day
warranty:
----------------------------------------------------------------------

Analyzers:
==========
HEWLETT PACKARD 331A Distortion Analyzer Rack Mount, late model (gold
plated circuit boards, red ring binding posts), excellent, with copy
of manual: $135 (26 lbs)

HEWLETT PACKARD 334A Distortion Analyzer, Very late model (gold plated
circuit boards, red ring binding posts), Excellent, with copy of
manual: $175 (26 lbs)

HEWLETT PACKARD 302A Wave Analyzer, Very Good, some calibration sticker
goo, with copy of manual: $225 (51 lbs)

HEWLETT PACKARD 3551A Transmission Test Set, 40 Hz to 60 kHz, Good all
in one Auto Test set: Signal Generator, Level Meter, and Frequency
Counter. Has 600 Ohm termination on Banana Jacks, Battries dead but
works on AC, Very good condition: $150


Oscilloscopes:
==============
TEKTRONIX 465 Oscilloscope, Classic Portable dual channel, delayed
sweep 100 MHz scope: Excellent condition, except for a few paint chips
on case: $275 (37 lbs)

TEKTRONIX 310A Oscilloscope, All Tube, Excellent: $150 (34 lbs)

TEKTRONIX 503 Oscilloscope Cool collector's item, almost mint, with
Original RM503 Manual: $100 (38 lbs)


Oscillators/Signal Generators:
=============================
HEWLETT-PACKARD 200CD Oscillator, 5 Hz to 600 kHz, Excellent (some
sticker scrape) Late Model Blue Case, Lower Distortion with copy of
manual: $75 (25 lbs)

HEWLETT-PACKARD 200CD Oscillator, 5 Hz to 600 kHz, Very good, tan case,
with copy of manual, $50 (25 lbs)

BARKER AND WILLIAMSON (B&W) 200 Audio Oscillator, 20Hz-20kHz, Silky
smooth tuning, excellent:$60 (15 lbs)

EICO 377 Sine and Square Wave Audio Oscillator, Factory Built,
excellent plus (near mint) Condition, Brushed Alum Cosmetics, With copy
of operating and service manual $50 (14 lbs)

HEATH SQ-1 Square Wave Generator Mid-Late 50's vintage collectors item.
Almost mint. $60 (10 lbs)


AC Voltmeters/ Power Meters:
============================
HEWLETT-PACKARD 400E AC Voltmeter with copy of manual: $125

GENERAL RADIO 1840A Output Power Meter 20Hz-20KHz 0.1 mW - 20 Watts,
with copy of Manual excellent: $150 (17 lbs)


VARIACs:
========
TECHNIPOWER (GENERAL RADIO) W8 VARIAC 0/140V/8.5 Amp Panel Mount NOS
New in original Packing : $125

GENERAL RADIO W5 VARIAC 0-140V 5 Amp Panel Mount, excellent: $50 (8
lbs)


Other:
======
SPENCER KENNEDY LABS (SKL) 320 Variable Filter 2 Channels, 20Hz-20kHz,
tube type, excellent: $250 (30lbs)

SPENCER KENNEDY LABS (SKL) 300 Variable Filter, Single Channel very
good condx: $150 (20 lbs)

HEWLETT PACKARD 6215A Bench Power Supply 0-25V, excellent: $50 (10 lbs)

HEWLETT-PACKARD 7560A Logarithmic Convertor: $50 (as-is)

ALTEC 455B Line Amp: $50 (as-is)

GENERAL ELECTRIC TF4RX02NA Power Transformer Has Four 32 volt @ 4 Amp
windings. Primary tapped for 109,115,120,126, and 132 Volts. Great
for 200-300 Watt Solid State Amp, two available: $50 each

NEW Bird Model 74 Coaxwitch, 6 Position Coax Switch "N" Type, Original
cost is near $500: $150 (5 lbs)


Catalogs:
=========
HEWLETT PACKARD 1983 Catalog Sealed in original packing $50

Fluke 1989, excellent: $25
Hewlett Packard 1969, excellent: $40
Hewlett Packard 1969, tear on spline: $30
Hewlett Packard 1972, excellent: $40
Hewlett Packard 1973, excellent: $40
Hewlett Packard 1977, excellent: $40
Hewlett Packard 1979, excellent: $40
Hewlett Packard 1983, excellent: $40
Hewlett Packard 1987, excellent: $40
Hewlett Packard 1988, excellent: $40
Hewlett Packard 1991, excellent: $25
Hewlett Packard 1992, excellent: $25
Tektronix 1989, excellent: $25
Tektronix 1994, excellent: $20

NON-WORKING UNITS, Sold As-Is, No warranty:
-------------------------------------------
EICO 377 Sine and Square Wave Audio Oscillator Original style blue
cosmetics, Excellent condx, tubes light up, but missing handle and
phone jack added to front panel, with copy of manual: $25 (14 lbs)

BOONTON 260A "Q" Meter, Good Oscillator and Good Bolometer
(heater/thermocouple), but bad meter movement (top Q indictor meter),
otherwise excellent, with copy of manual: $100 (50 lbs)

TEKTRONIX 432 Oscilloscope, 2 Channel, Not working, missing a few
knobs, parts unit: $30 (30 lbs)

TEKTRONIX 561A Oscilloscope, no plug-ins, Not working, $25 (41 lbs)

TEKTRONIX 422 Oscilloscope, AC/DC, portable 2 channel, complete but not
working: $30 (32 lbs)
CI-94 Universal Service Oscilloscope Made In USSR Solid State, with
original box and accessories and 10:1 Probe, not working: $40 (15 lbs)

HEATH AG-7 Sine / Square Oscillator Early 50's needs work, Line cord
plug gone, otherwise looks complete with tubes: $25

-------------------------------------------------
Shipping: All items are plus actual shipping charges from Zip Code
20191, no inflated shipping or handling, insurance is always included.
Send Zip Code for estimate. Shipment to US only.

Terms: Pre-paid by PayPal (for orders over $100 and to confirmed
address only), Postal Money Order or check (10 day clear).

Returns: I honor a 7 day right to return and a 30 day warranty (except
for As-Is items). Sorry but I cannot refund shipping on returns.


Thanks for looking,

Mike Nowlen
mnowlen@comcast.net

Have genuine BRC meter movements for that Q-meter...

 

[John Miles]

In article <1114054114.057966.84080@g14g2000cwa.googlegroups.com>,
joe4702@hotmail.com says...

Thanks for the link. I will join.
After playing with the 2445 vs. the 3000s at work, I am starting to see
your point.

Sphere Electronics claims to be able to ship those 2440/2460-series
hybrids off to Japan for repair(!) You might ask about that on the
TekScopes list if you're interested.

-- jm

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

 

[kishikawa]

Hi Nick.

I maybe fixed LeCroy 9450A Oscilloscope intermittent problems.

1.100MHz Xtal is poor ----> change to 100MHz Xtal OSC.

2.ECL power supply is -3.6V ----> correct to -5.0V.
Most of time it supply -5.0V.
I found it drop to -3.6V when LeCroy 9450A is not work fine.
Variable resister for voltage adjustment in power supply unit is bad.

Nick Check power supply voltages.
-15V,+15V,-5V,+5V is correct or not .

Thank you Kishikawa

 

The man who apparently convinced Tektronix to release their manuals to
the public domain, David Hopkins, has left a message on yahoo groups
offering the help of his experience...

http://groups.yahoo.com/group/hp_agilent_equipment/message/1129

Note also, that for HP to release these manuals to the public domain,
would be an act of charity towards third-world and developing nations,
where used test equipment can be of great service. I hope that someone
with inside knowledge of Agilent management can take this forward...

Stepan

 

[Ulrich Bangert]

Radra,

the "Null" feature is used to remove offsets that may arise in the internal
circuitry of the power meter. So if you notice a nonzero indication of the
meter with no rf power applied to the sensor, simply press the "Null" bottom
to get a zero reading of the meter. Probably you may have to repeat this a
number of times. You will need this feature only in the most sensible
measure ranges, say 100 microwatts downward.

Regards
Ulrich



"Radra" <radra@adelphia.net> schrieb im Newsbeitrag
news:1114453997.238898.305400@z14g2000cwz.googlegroups.com...

Can anyone tell me how to utilize the "NULL" feature of the 431B power
meter? Have both a 431B and 431C but no manuals, so am unsure if I am
making proper use of this front panel null feature.

 

mroberds@worldnet.att.net wrote:

Have a USB port somewhere on the instrument. Plug in a flash drive,
push a button, and get a .txt or .pdf dumped to the flash drive.

Better yet, have a Flash ROM USB device buried in the instrument.
Plug in a PC and read out the file. Old instruments are easily
upgraded with a keychain ROM device and a glue gun.

Given the prices of keychain RAM drives, ROM or WORM devices have to
be nearly free...

 

[Rich Grise]

On Sat, 30 Apr 2005 05:07:19 +0000, mroberds wrote:

In sci.electronics.repair Dave <nospam@nowhere.com> wrote:
The manual in question (HP 5370B time interval counter) is dated 1995,
part number 05370-90031. The equipment is no longer supported.

A few observations:

- If the manual is separate from the instrument, it will get separated
from the equipment and lost. Doesn't matter if it's on paper, a CD,
a website, or whatever.

- In these latter days, memory is cheaper than dirt. Especially if
it's ROM.

- Small flash-memory drives with a USB connector are rather ubitiquous.

So... why not store the manuals INSIDE the instruments, and not have
this problem again?

Because, when the instrument breaks, you're right back in the same boat.

Cheers!
Rich

 

[Theo v. Werkhoven]

The carbonbased lifeform Ulrich Bangert inspired sci.electronics.equipment with:

Radra,

the "Null" feature is used to remove offsets that may arise in the internal
circuitry of the power meter. So if you notice a nonzero indication of the
meter with no rf power applied to the sensor, simply press the "Null" bottom
to get a zero reading of the meter. Probably you may have to repeat this a
number of times. You will need this feature only in the most sensible
measure ranges, say 100 microwatts downward.

"Radra" <radra@adelphia.net> schrieb im Newsbeitrag
news:1114453997.238898.305400@z14g2000cwz.googlegroups.com...
Can anyone tell me how to utilize the "NULL" feature of the 431B power
meter? Have both a 431B and 431C but no manuals, so am unsure if I am
making proper use of this front panel null feature.

Do not forget to terminate (50Ohm) the sensor first, otherwise the
calibration is invalid.
It is also advisible to let the 431 warm up first, or you'll be
repeating the calibration a couple of times.

Theo
--
theo at van-werkhoven.nl ICQ:277217131 SuSE Linux
linuxcounter.org: 99872 Jabber:muadib at jabber.xs4all.nl AMD XP2100+ 512MB

 

John Larkin <jjlarkin@highnotlandthistechnologypart.com> wrote:

We recently introduced a benchtop instrument that has a 'help' key on
the front panel.

This is very much in the right direction. However, as you note...

I wrote a lot of the help text. It was interesting to try to write
clear and coherent stuff that looks good on a 20-character-wide
display... lots of synonym searching and syntax shuffling was
involved. Lots.

....it's not a substitute for a full manual. I have designed a layout
of three 20x4 screens on a (very much simpler) instrument. Each one
had to display some data plus give labels for soft keys to switch
screens, and even this was interesting to make fit.

Many high-end instruments now have a VGA-quality display and have
serious help facilities; you could put the real manual into something
like that.

True. It might be nice, though, to be able to get it printed somehow,
or at least read it on a machine with a full keyboard so you could do
text searches and such.

Good idea about a web site inside the instrument; we'll have to try
that some day.

One of the problems I see with this is that you need to know the IP
address of the instrument to make this work. If the IP address is
fixed and noted on the serial number label or something, it's easy.
If the user can adjust it, or if it uses DHCP, it might be trickier...
you'd need to have a way to show it on the built-in display or
otherwise make it known to the user so they know where to point their
browser. I guess you could put the MAC address on the serial number
label and let the user use ARP to figure it out. Another way might
be to have a note on the case that holding the "4" key during power-up
resets the IP address to 10.0.0.1 or whatever. A clever user could
directly connect the instrument to the PC and run a port scan, although
this might take a while.

You know what would be entertaining? Put the manual on the instrument's
internal Web site, and then ship exactly one piece of printed
documentation with the instrument: a piece of paper that explains how
to access the manual. Put a Web bug in the last page of the manual that
loads from your Internet Web site and logs the serial number of the
instrument. You could work out exactly how many people actually RTFM...
(OK, this isn't practical for marketing/customer acceptance/privacy
reasons, but it would be fun.)

To the other points that have been raised: I was originally thinking
of using the instrument's built-in CPU so all the user would need would
be a "dumb" flash drive. However, if the user has a flash drive, there
is also a PC available to read the files on it, so it's not too
unreasonable to put the ROM USB drive in the instrument and let the
user hook up a PC. Also, the ROM drive can then be powered over the USB
port, so it will work even if the instrument is broken -- unless the
instrument got stepped on by an elephant or something. This also means
that the USB port can be isolated from the instrument circuitry, which
could be important for safety reasons. Also, a ROM drive with USB
connector could conceivably be small enough to include in something like
a hand-held DMM. The ROM would make it a little harder to include the
addenda pages - maybe the drive has a big ROM and a little flash chip to
make this possible. I still want to use ROM because if it can be erased
it will be. I am also quite serious about this being firmly attached
(potted?) to the instrument... if it's not, people will remove and
promptly misplace it, or sell it separately from the instrument later.

Matt Roberds

 

[John Larkin]

On Sat, 30 Apr 2005 05:07:19 GMT, mroberds@worldnet.att.net wrote:

In sci.electronics.repair Dave <nospam@nowhere.com> wrote:
The manual in question (HP 5370B time interval counter) is dated 1995,
part number 05370-90031. The equipment is no longer supported.

A few observations:

- If the manual is separate from the instrument, it will get separated
from the equipment and lost. Doesn't matter if it's on paper, a CD,
a website, or whatever.

- In these latter days, memory is cheaper than dirt. Especially if
it's ROM.

- Small flash-memory drives with a USB connector are rather ubitiquous.

So... why not store the manuals INSIDE the instruments, and not have
this problem again?

Have a USB port somewhere on the instrument. Plug in a flash drive,
push a button, and get a .txt or .pdf dumped to the flash drive. A
fancy instrument could use a menu selection to dump a nice PDF from
a big ROM; an inexpensive one could use a little recessed switch on
the back panel to bit-bang a text file out the USB port with an 8051
or something. Perhaps even a serial port doing an ASCII (or Kermit
or similar) transfer for a really low-dollar solution. Instruments
fancy enough to have their own Ethernet / Web server could simply
serve documents through that interface. If they just have Ethernet
and TCP/IP, maybe a "magic packet" to a well-known port (17?) on a
non-routable IP address could trigger a manual dump via FTP.

The storage inside the instrument would need to be in ROM, or else it
will eventually get erased. If the instrument takes firmware updates,
there should be a mechanism for the updates to include addenda pages
in the manual dump, but the updates shouldn't be able to overwrite the
original manual.

This won't do a thing for all those instruments floating around out
there now. (Or maybe this has already been thought of and implemented;
I don't get to buy much brand multi-kilodollar test equipment at work.)
But if the market could agree on some kind of standard, and get the
vendors to accept it, the "missing manual" problem could be reduced
a great deal.

We recently introduced a benchtop instrument that has a 'help' key on
the front panel.

http://www.highlandtechnology.com/DSS/P400DS.html

It's scrolled with the spinner knob. The first thing you see is an
introduction to how to use help, and how to get out. Then there's a
table of contents. Both the toc and the main text include hyperjumps
(push the spinner) or you can hit any of the other buttons on the
front panel to jump to the specific section that's relevant.

I wrote a lot of the help text. It was interesting to try to write
clear and coherent stuff that looks good on a 20-character-wide
display... lots of synonym searching and syntax shuffling was
involved. Lots.

Many high-end instruments now have a VGA-quality display and have
serious help facilities; you could put the real manual into something
like that.

Good idea about a web site inside the instrument; we'll have to try
that some day.

John

 

[mc]

So... why not store the manuals INSIDE the instruments, and not have
this problem again?

How about on a CD in an envelope inside the case?

That way it's immune to electrical damage to the instrument itself.

 

[Allen McCann]

If any one is interested I found a website that has a 2200W
inverter/charger for $360.00.
Cheapest I have found - don't know how good they are.

http://inverterchargersite.com/

Allen

 

[Jim Yanik]

"HedgeWarden" <HedgeWarden@msn.com> wrote in
news:1115134136.907997.155370@f14g2000cwb.googlegroups.com:

Jerry,

Original feet are very hard to find, except used. However, I have been
making reproduction feet. Please check my site:

http://www.members.aol.com/hedgewarden/400feet/

As for the mounting screw - the 465 and other scopes of that generation
used a press-fit stud rather than a screw. I doubt you can find a
screw with a small enough head to clear the chassis when it slides into
the case.

I used to use countersunk-head screws with a lockwasher when repairing 465
cabinets.Worked fine.

--
Jim Yanik
jyanik
at
kua.net

 

[Robert Baer]

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..

Errr.....

Say you bought a *meter* that could detect pulses like that, and say
it gave readings of pulse width and amplitude.
Then what?
The meter would be useless for doing something else, specifically
flashing an LED.
You do not want or need a meter.
Some simple logic and timers will do the job.
The input pulse could drive a comparitor (or two) to determine
amplitude (or amplitude range); the output feeds a one-shot and logic to
determine pulse width, and the output then drives an LED flasher (a
timer and driver).

 

[DaveM]

"Robert Baer" <robertbaer@earthlink.net> wrote in message
news:xAYde.6514$BE3.1848@newsread2.news.pas.earthlink.net...

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..

Errr.....
Say you bought a *meter* that could detect pulses like that, and say it
gave readings of pulse width and amplitude.
Then what?
The meter would be useless for doing something else, specifically
flashing an LED.
You do not want or need a meter.
Some simple logic and timers will do the job.
The input pulse could drive a comparitor (or two) to determine amplitude
(or amplitude range); the output feeds a one-shot and logic to determine
pulse width, and the output then drives an LED flasher (a timer and
driver).

The operative term for what you need is a Pulse Stretcher.
Take a look at the datasheet for the LM555 timer.
http://www.national.com/ds/LM/LM555.pdf
The LM555 will do what you want in monostable mode. The datasheet describes
the circuit and equations to design it.

If you don't feel that you can handle the details of designing the circuit,
you might download freebie designer software at
http://www.schematica.com/555_Timer_design/555.htm and let your computer do
the work for you. For the output pulse width, you would probably have to
use something in the neighborhood of 250 ms in order to make the flash of
the LED visible.
Amplitude is a minor problem here, since your pulse is too low to trigger
the 555 timer. A simple opamp or comparator circuit will do the job nicely.
If you try this approach, first select the 555 Monostable button, then
select either the Positive Edge Triggered Monostable or the Negative Edge
Triggered Monostable, depending on the polarity of the pulse coming from the
opamp/comparator.

If you're only driving a single LED, the 555 output can drive it directly.
Be sure to put a limiting resistor in series with the LED.

--
Dave M
MasonDG44 at comcast dot net (Just subsitute the appropriate characters in
the address)

Never take a laxative and a sleeping pill at the same time!!

 

[Robert Lacoste]

<krishmaniac@hotmail.com> a écrit dans le message de news:
1115275285.939910.269190@g14g2000cwa.googlegroups.com...

Hi,
Why do not the oscilloscope used for noise measurement, where we can
use the FFT feature of the scope. Most of the time it is seen that
expensive spectrum analysers are used. Any comments on it and
discussion are most welcomed.

Because even high end oscilloscope have a 8 bit ADC, providing a dynamix
range less than 1/250 in voltage, or around 24dB(in voltage), or around
48dB(in power). The worst spectrum analyzers have 80dB of dynamic range...

Robert

 

[John Miles]

In article <1115214530.081246.299280@o13g2000cwo.googlegroups.com>,
pdmtr@yahoo.com says...

Hi
I need to find a source to buy the Bus and coaxial (4 coaxial version)
interconnection cables for my HP 8567A Spextrum Analyzer. Any one know
a good source

http://www.glkinst.com/cables/hp_cables.htm

(inexpensive)???

Oops.

-- jm

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