In the Mkt for a HP Bench DMM

[Robert Baer]

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

"Chuck Harris" <cf-NO-SPAM-harris@erols.com> wrote in message
news:XaadnS2pNrLC3OHfRVn-rw@rcn.net...

Watson A.Name - "Watt Sun, the Dark Remover" wrote:


You can look on Tuckers web site and find the specs on most all

these

meters.


Thanks for all the good info. I found a single 3478A on Tucker's
website and it was $795 so I don't think I'll be back there soon.

I wonder why tucker let me have mine for so cheap? Cheap isn't

usually

their thing. When I was buying and selling a lot of surplus, I would

use

5 to 10 cents on a tucker dollar as a guide for what I should bid at
DRMO auctions. Their catalogs used to be a true gem to have.


In the last wk I've seen the 3478A go for anywhere from $75 to $220

on

ebay, most are well over a hundred. I'm still waiting for another

one

to come for bid at a reasonable price. Right now someone has one

for

sale, but this is like his first sale, and I don't think anyone

wants to

put very much money up for bid because he may be just a fraudster.

I think the odds of this guy being a fraud are reasonably large. His
presentation is very polished, and is full of contractual terms that

aren't

likely to have occurred to a first time seller. I would think it is

more

likely that he has sold a lot on ebay, but has changed his account

name

for some reason.

If I were truly interested in this unit, I would contact him, and ask

him

why the low seller number... and what was his previous id. His answer

might

allow you to bid.

-Chuck


Well, a few minutes before it ended, I bid on a HP 3478A DMM, and no one
else bid on it, so I won, for $75.00. It's from Teoutlet, which is
Tucker. I gotta wait for them to contact me for some reason, because
they have to charge me for sales tax because I live in Calif. It's
something less than six bucks, With shipping, it'll come to somewhat
under a hundred. At that price, I could buy another and have a spare.
;-)

So now I gotta get some manuals, and I'd really like some 4-wire test
probes. I've never seen them, but knowing HP and the likes, a new set
will probably cost a lot.

But here's the question I hinted at a while back, that I was gonna ask.
I think I might've run across something like this when I did a search
for Keithley stuff on Ebay. What I wonder is how do I automate a test
jig. I took a double pole, 6 position rotary switch and mounted it and
some terminal strips to a piece of wood. I can then connect my DMM to
the wipers, so I can then run wires to the different test points on the
jig and then just turn the rotary switch to whatever place I want to
measure. I would guess that there is something similar, but all
electronic from somewhere. I don't remember ever seeing anything like
it from HP or Fluke. I think Keithley may have something like it, tho.
A bunch of relays with driver transistors could be connected to a
parallel port and controlled by a program on a PC.



The relay method would be better; less kludgy.

I like the Axicom V23105-A5003-A201 for low to medium voltages, and
the NEC MR62-12UKSRY for higher voltages; both are 12V 960 ohm coil DPDT
16 pin DIP relays.
I wire up a socket and plug them in; makes it easy to replace when i
abuse them.
Mouser carries both.

 

[Watson A.Name - \"Watt Su]

"Robert Baer" <robertbaer@earthlink.net> wrote in message
news:fr_fe.357$r7.349@newsread1.news.pas.earthlink.net...

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

[snip]

Well, a few minutes before it ended, I bid on a HP 3478A DMM, and no
one
else bid on it, so I won, for $75.00. It's from Teoutlet, which is
Tucker. I gotta wait for them to contact me for some reason,
because
they have to charge me for sales tax because I live in Calif. It's
something less than six bucks, With shipping, it'll come to
somewhat
under a hundred. At that price, I could buy another and have a
spare.
;-)

So now I gotta get some manuals, and I'd really like some 4-wire
test
probes. I've never seen them, but knowing HP and the likes, a new
set
will probably cost a lot.

But here's the question I hinted at a while back, that I was gonna
ask.
I think I might've run across something like this when I did a
search
for Keithley stuff on Ebay. What I wonder is how do I automate a
test
jig. I took a double pole, 6 position rotary switch and mounted it
and
some terminal strips to a piece of wood. I can then connect my DMM
to
the wipers, so I can then run wires to the different test points on
the
jig and then just turn the rotary switch to whatever place I want to
measure. I would guess that there is something similar, but all
electronic from somewhere. I don't remember ever seeing anything
like
it from HP or Fluke. I think Keithley may have something like it,
tho.
A bunch of relays with driver transistors could be connected to a
parallel port and controlled by a program on a PC.

The relay method would be better; less kludgy.
I like the Axicom V23105-A5003-A201 for low to medium voltages, and
the NEC MR62-12UKSRY for higher voltages; both are 12V 960 ohm coil
DPDT
16 pin DIP relays.
I wire up a socket and plug them in; makes it easy to replace when
i
abuse them.
Mouser carries both.

Thanks for the info. I had several 5V dip relays that I got from rat
shack long ago on clearance. Probably stuck away in the garage in some
box, still in their blister packs. I wish I could get an old Strowger
switch from the '50s telephone surplus stuff. They're a rotary stepping
switch, with lots of contacts.

 

[Chuck Harris]

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

Well, a few minutes before it ended, I bid on a HP 3478A DMM, and no one
else bid on it, so I won, for $75.00. It's from Teoutlet, which is
Tucker. I gotta wait for them to contact me for some reason, because
they have to charge me for sales tax because I live in Calif. It's
something less than six bucks, With shipping, it'll come to somewhat
under a hundred. At that price, I could buy another and have a spare.
;-)

Hi Watson, Great! I don't know why people are bidding up that guy that
has *zero* sales, and a *trust-me* price on shipping. He is already up to
$76! And as you know, your tucker meter was sitting there unmolested.

I bet another TE 3478A appears, exactly the same terms, before the week
is out.

So now I gotta get some manuals, and I'd really like some 4-wire test
probes. I've never seen them, but knowing HP and the likes, a new set
will probably cost a lot.

As to the manual, a complete 3478A manual can be downloaded for free from

http://www.logsa.mil

click on the icon for test and equiptment publications, accept their
"terms" (believe me, you have a right to be there!), and enter a title
search on "3478A" (caps are important!) And there it will be.

It appears to be the standard HP manual.

But here's the question I hinted at a while back, that I was gonna ask.
I think I might've run across something like this when I did a search
for Keithley stuff on Ebay. What I wonder is how do I automate a test
jig. I took a double pole, 6 position rotary switch and mounted it and
some terminal strips to a piece of wood. I can then connect my DMM to
the wipers, so I can then run wires to the different test points on the
jig and then just turn the rotary switch to whatever place I want to
measure. I would guess that there is something similar, but all
electronic from somewhere. I don't remember ever seeing anything like
it from HP or Fluke. I think Keithley may have something like it, tho.
A bunch of relays with driver transistors could be connected to a
parallel port and controlled by a program on a PC.

HP sold a hpib controlled relay actuator, HP59306A. It usually goes for
spit on ebay. It is simple to program, and makes these kind of chores
easy.

-Chuck

 

[Robert Baer]

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

"Robert Baer" <robertbaer@earthlink.net> wrote in message
news:fr_fe.357$r7.349@newsread1.news.pas.earthlink.net...

Watson A.Name - "Watt Sun, the Dark Remover" wrote:


[snip]


Well, a few minutes before it ended, I bid on a HP 3478A DMM, and no

one

else bid on it, so I won, for $75.00. It's from Teoutlet, which is
Tucker. I gotta wait for them to contact me for some reason,

because

they have to charge me for sales tax because I live in Calif. It's
something less than six bucks, With shipping, it'll come to

somewhat

under a hundred. At that price, I could buy another and have a

spare.

;-)

So now I gotta get some manuals, and I'd really like some 4-wire

test

probes. I've never seen them, but knowing HP and the likes, a new

set

will probably cost a lot.

But here's the question I hinted at a while back, that I was gonna

ask.

I think I might've run across something like this when I did a

search

for Keithley stuff on Ebay. What I wonder is how do I automate a

test

jig. I took a double pole, 6 position rotary switch and mounted it

and

some terminal strips to a piece of wood. I can then connect my DMM

to

the wipers, so I can then run wires to the different test points on

the

jig and then just turn the rotary switch to whatever place I want to
measure. I would guess that there is something similar, but all
electronic from somewhere. I don't remember ever seeing anything

like

it from HP or Fluke. I think Keithley may have something like it,

tho.

A bunch of relays with driver transistors could be connected to a
parallel port and controlled by a program on a PC.



The relay method would be better; less kludgy.
I like the Axicom V23105-A5003-A201 for low to medium voltages, and
the NEC MR62-12UKSRY for higher voltages; both are 12V 960 ohm coil

DPDT

16 pin DIP relays.
I wire up a socket and plug them in; makes it easy to replace when

i

abuse them.
Mouser carries both.



Thanks for the info. I had several 5V dip relays that I got from rat
shack long ago on clearance. Probably stuck away in the garage in some
box, still in their blister packs. I wish I could get an old Strowger
switch from the '50s telephone surplus stuff. They're a rotary stepping
switch, with lots of contacts.


The rotary steppers sometimes show up in ham electronic flea markets;

otherwise snoop in electronic surplus stores.

 

[Robert Baer]

Chuck Harris wrote:

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

Well, a few minutes before it ended, I bid on a HP 3478A DMM, and no one
else bid on it, so I won, for $75.00. It's from Teoutlet, which is
Tucker. I gotta wait for them to contact me for some reason, because
they have to charge me for sales tax because I live in Calif. It's
something less than six bucks, With shipping, it'll come to somewhat
under a hundred. At that price, I could buy another and have a spare.
;-)


Hi Watson, Great! I don't know why people are bidding up that guy that
has *zero* sales, and a *trust-me* price on shipping. He is already up to
$76! And as you know, your tucker meter was sitting there unmolested.

I bet another TE 3478A appears, exactly the same terms, before the week
is out.


So now I gotta get some manuals, and I'd really like some 4-wire test
probes. I've never seen them, but knowing HP and the likes, a new set
will probably cost a lot.


As to the manual, a complete 3478A manual can be downloaded for free from

http://www.logsa.mil

click on the icon for test and equiptment publications, accept their
"terms" (believe me, you have a right to be there!), and enter a title
search on "3478A" (caps are important!) And there it will be.

It appears to be the standard HP manual.


But here's the question I hinted at a while back, that I was gonna ask.
I think I might've run across something like this when I did a search
for Keithley stuff on Ebay. What I wonder is how do I automate a test
jig. I took a double pole, 6 position rotary switch and mounted it and
some terminal strips to a piece of wood. I can then connect my DMM to
the wipers, so I can then run wires to the different test points on the
jig and then just turn the rotary switch to whatever place I want to
measure. I would guess that there is something similar, but all
electronic from somewhere. I don't remember ever seeing anything like
it from HP or Fluke. I think Keithley may have something like it, tho.
A bunch of relays with driver transistors could be connected to a
parallel port and controlled by a program on a PC.


HP sold a hpib controlled relay actuator, HP59306A. It usually goes for
spit on ebay. It is simple to program, and makes these kind of chores
easy.

-Chuck
My browser sez "www.logsa.mil could not be found".

What's up?

 

[Chuck Harris]

Robert Baer wrote:

HP sold a hpib controlled relay actuator, HP59306A. It usually goes for
spit on ebay. It is simple to program, and makes these kind of chores
easy.

-Chuck

My browser sez "www.logsa.mil could not be found".
What's up?

It's the usual thing, I thought I remembered the address, and didn't double
check. The actual address is:

https://www.logsa.army.mil/pubs.htm

Your browser must have 128bit encription, or better, or they won't let you play.


-Chuck

 

[Watson A.Name - \"Watt Su]

"Chuck Harris" <cf-NO-SPAM-harris@erols.com> wrote in message
news:Te6dnUONCucuOR3fRVn-iA@rcn.net...

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

Well, a few minutes before it ended, I bid on a HP 3478A DMM, and no
one
else bid on it, so I won, for $75.00. It's from Teoutlet, which is
Tucker. I gotta wait for them to contact me for some reason,
because
they have to charge me for sales tax because I live in Calif. It's
something less than six bucks, With shipping, it'll come to
somewhat
under a hundred. At that price, I could buy another and have a
spare.
;-)

Hi Watson, Great! I don't know why people are bidding up that guy
that
has *zero* sales, and a *trust-me* price on shipping. He is already
up to
$76! And as you know, your tucker meter was sitting there unmolested.

The final bid was $143.50 so it looks like the bidders trusted the
seller. Somewhat. Some 3478As go for over $200.

I bet another TE 3478A appears, exactly the same terms, before the
week
is out.


So now I gotta get some manuals, and I'd really like some 4-wire
test
probes. I've never seen them, but knowing HP and the likes, a new
set
will probably cost a lot.


As to the manual, a complete 3478A manual can be downloaded for free
from

http://www.logsa.mil

That didn't work, so I added www.logsa.army.mil. I got time out error
on that, tho. I tried again just now, and again got a timeout error.
Looks like they're blocking me, and I'll never be able to access that
website.

click on the icon for test and equiptment publications, accept their
"terms" (believe me, you have a right to be there!), and enter a title
search on "3478A" (caps are important!) And there it will be.

It appears to be the standard HP manual.

Looks like I'm stuck with buying one. I've seen some on CD-R, for
cheap. I wonder how good or bad the image quality is.

But here's the question I hinted at a while back, that I was gonna
ask.
I think I might've run across something like this when I did a
search
for Keithley stuff on Ebay. What I wonder is how do I automate a
test
jig. I took a double pole, 6 position rotary switch and mounted it
and
some terminal strips to a piece of wood. I can then connect my DMM
to
the wipers, so I can then run wires to the different test points on
the
jig and then just turn the rotary switch to whatever place I want to
measure. I would guess that there is something similar, but all
electronic from somewhere. I don't remember ever seeing anything
like
it from HP or Fluke. I think Keithley may have something like it,
tho.
A bunch of relays with driver transistors could be connected to a
parallel port and controlled by a program on a PC.

HP sold a hpib controlled relay actuator, HP59306A. It usually goes
for
spit on ebay. It is simple to program, and makes these kind of chores
easy.

I found a few on Ebay for anywhere from $15 to almost $200. I checked
out a pic of one, and it looks like it is connected to the outside world
with a GPIB or HPIB cable. I don't have one of those and from what I've
seen they cost major money new, and they're uncommon in the used or
surplus world.

I suppose that the thing can be actuated manually. But then I've
already got the rotary switch that I mickey moused, which works to a
certain point. And I feel real confident about its simplicty and
operation.

Thanks for the info.

> -Chuck

 

[Robert Baer]

Chuck Harris wrote:

Robert Baer wrote:

HP sold a hpib controlled relay actuator, HP59306A. It usually goes for
spit on ebay. It is simple to program, and makes these kind of chores
easy.

-Chuck


My browser sez "www.logsa.mil could not be found".
What's up?


It's the usual thing, I thought I remembered the address, and didn't double
check. The actual address is:

https://www.logsa.army.mil/pubs.htm

Your browser must have 128bit encription, or better, or they won't let
you play.


-Chuck
That works!

Thanks.

 

[Watson A.Name - \"Watt Su]

"Chuck Harris" <cf-NO-SPAM-harris@erols.com> wrote in message
news:XeSdnRFwLvtgbh3fRVn-jw@rcn.net...

Robert Baer wrote:

HP sold a hpib controlled relay actuator, HP59306A. It usually
goes for
spit on ebay. It is simple to program, and makes these kind of
chores
easy.

-Chuck

My browser sez "www.logsa.mil could not be found".
What's up?

It's the usual thing, I thought I remembered the address, and didn't
double
check. The actual address is:

https://www.logsa.army.mil/pubs.htm

Your browser must have 128bit encription, or better, or they won't let
you play.

Thanks. I finally got on, and d/l'd the .PDF, almost 2.5 megs. I saw
that it has some gotchas. Like it has a CMOS mem backup battery, which
can go bad or leak. I haven't had a chance to look at the parts list
but hopefully it's a lithium, which don't seem to get thegrunge like
some old batteries. Back in the late '80s we upgraded over 300 ATs with
386 MoBos, and I used to pull off the Varta mem backup batteries that
were on the old 286 MoBos and I put 'em in a cardboard box in a
cupboard. Later, the whole bottom of the box turned brown from the
leakage and I had to almost treat them as toxic waste.

The 3478A that I bid on looke a bit beat up in the pic. I'm hoping that
the thing's in working order. I haven't yet heard from the company,
which is supposed to contact me in two business days. I'll have to
contct them tomorrows.

> -Chuck

 

[Chuck Harris]

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

That didn't work, so I added www.logsa.army.mil. I got time out error
on that, tho. I tried again just now, and again got a timeout error.
Looks like they're blocking me, and I'll never be able to access that
website.


click on the icon for test and equiptment publications, accept their
"terms" (believe me, you have a right to be there!), and enter a title
search on "3478A" (caps are important!) And there it will be.

It appears to be the standard HP manual.


Looks like I'm stuck with buying one. I've seen some on CD-R, for
cheap. I wonder how good or bad the image quality is.

I suppose, that this being a binaries group, I could post the manual for
you.

HP sold a hpib controlled relay actuator, HP59306A. It usually goes

for

spit on ebay. It is simple to program, and makes these kind of chores
easy.


I found a few on Ebay for anywhere from $15 to almost $200. I checked
out a pic of one, and it looks like it is connected to the outside world
with a GPIB or HPIB cable. I don't have one of those and from what I've
seen they cost major money new, and they're uncommon in the used or
surplus world.

I presumed that, if you were planning on using your new 3478A as part of
the automation rig, you would be using HPIB.

I designed an HPIB controlled relay driver as part of the gear I automated
for my thesis. It uses a few TTL chips. I can post that if you'd like.

I suppose that the thing can be actuated manually. But then I've
already got the rotary switch that I mickey moused, which works to a
certain point. And I feel real confident about its simplicty and
operation.

Yes, but that is hardly what I would call automation.

-Chuck

 

[Chuck Harris]

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

Thanks. I finally got on, and d/l'd the .PDF, almost 2.5 megs. I saw
that it has some gotchas. Like it has a CMOS mem backup battery, which
can go bad or leak. I haven't had a chance to look at the parts list
but hopefully it's a lithium, which don't seem to get thegrunge like
some old batteries. Back in the late '80s we upgraded over 300 ATs with
386 MoBos, and I used to pull off the Varta mem backup batteries that
were on the old 286 MoBos and I put 'em in a cardboard box in a
cupboard. Later, the whole bottom of the box turned brown from the
leakage and I had to almost treat them as toxic waste.

The 3478A that I bid on looke a bit beat up in the pic. I'm hoping that
the thing's in working order. I haven't yet heard from the company,
which is supposed to contact me in two business days. I'll have to
contct them tomorrows.

It looked to me like it had one nick on the bezel, but the rest was sticker
grunge. Sticker grunge comes off nicely with lighter fluid (VM&P Naptha).
Mine cleaned up and looks like new... There were 6 or 7 stickers on it.

The battery is a very long life nonrechargable lithium. I think it will
be just fine.

If you paid Tucker by paypal or bidpay, you will probably find the instrument
is at your door. I received no contact from them, and after 3 days I got
curious, and emailed them. I got the package, and then I got the reply.

-Chuck

 

[Watson A.Name - \"Watt Su]

"Chuck Harris" <cf-NO-SPAM-harris@erols.com> wrote in message
news:et-dnSf5K4sUZBzfRVn-og@rcn.net...

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

That didn't work, so I added www.logsa.army.mil. I got time out
error
on that, tho. I tried again just now, and again got a timeout
error.
Looks like they're blocking me, and I'll never be able to access
that
website.


click on the icon for test and equiptment publications, accept their
"terms" (believe me, you have a right to be there!), and enter a
title
search on "3478A" (caps are important!) And there it will be.

It appears to be the standard HP manual.


Looks like I'm stuck with buying one. I've seen some on CD-R, for
cheap. I wonder how good or bad the image quality is.

I suppose, that this being a binaries group, I could post the manual
for
you.

I finally got it d/l'd and posted a followup. The d/l is a standard
Army Technical Manual. No problemo, it does have the schems and PCB
layout in the back.

HP sold a hpib controlled relay actuator, HP59306A. It usually goes

for

spit on ebay. It is simple to program, and makes these kind of
chores
easy.


I found a few on Ebay for anywhere from $15 to almost $200. I
checked
out a pic of one, and it looks like it is connected to the outside
world
with a GPIB or HPIB cable. I don't have one of those and from what
I've
seen they cost major money new, and they're uncommon in the used or
surplus world.

I presumed that, if you were planning on using your new 3478A as part
of
the automation rig, you would be using HPIB.

No automation rig, just the 3478A and something else to switch the probe
leads.

I designed an HPIB controlled relay driver as part of the gear I
automated
for my thesis. It uses a few TTL chips. I can post that if you'd
like.

I found a "Kelvin Clips" 4-wire probes on Ebay, it's more than what I
paid for the 3478A! Eighty-five bucks! And that's the cheaper one!

My guess is that a couple GPIB cables will go for over a hundred total,
so I really don't see that I'm gonna save a lot by making my own GPIB
stuff. I would just as well buy a used setup if I wanted to do that
much automation. I think for now the rotary switch is as far as I need
to go.

I suppose that the thing can be actuated manually. But then I've
already got the rotary switch that I mickey moused, which works to a
certain point. And I feel real confident about its simplicty and
operation.

Yes, but that is hardly what I would call automation.

I'm not really looking for automation, I'm looking for not having to
hold the probes at a half dozen test points and change them around a
half dozen times when I make an adjustment with a pot ot two, for
esample. I think some people probably just buy a half dozen ten dollar
DMMs and connect them up to the various test points. But they aren't
all that accurate ($10 DMMs have an AC range that's 200VAC, no lower),
and the batteries run down after several hours. I'd rather use a bench
DMM that I can leave on for awhile until the circuit reaches thermal
equilibrium, for example.

I have a couple wiggle stick D'arsonval meters that I use for current
measurements, and they work okay, and take no power. But one, for
example, has a full-scale reading of 15 mA, but it has an internal
resistance of 8 ohms. And that resistance in series with the supply can
distort the performance of the circuit. So I would rather put a 0.1 ohm
resistor in series with the supply lead, and then use a sensitive DVM to
get the current thru it. I suppose that I could put an opamp with a
couple precision resistors across the current resistor to give it a gain
of 10 or 100. That way, I could use a cheap DVM to do the measurement.
But I would need 2 or 3 or 4 of these to measure the current at various
points, so it looks like the whole measurement jig starts to get too
complicated. And then there's the problem with isolating the measuring
circuits from the circuit being measured.

One example that I've run into is when I measure the current draw of a
circuit. I break the + lead and insert the DMM, and get 90mA. But when
I reconnect the circuit without the DMM, it's drawing more current, like
100mA, and putting out more power. The DC resistance of the DMM is
disturbing the circuit. So I would rather leave a low value current
sensing resistor in the + supply lead permanently so the readings don't
change with every measurement change.

Thanks for putting up with my ramblings. But these are real world
problems for which I'm trying to find solutions.

> -Chuck

 

[Watson A.Name - \"Watt Su]

"Chuck Harris" <cf-NO-SPAM-harris@erols.com> wrote in message
news:UfSdndi6PpmKZhzfRVn-vA@rcn.net...

Watson A.Name - "Watt Sun, the Dark Remover" wrote:


Thanks. I finally got on, and d/l'd the .PDF, almost 2.5 megs. I
saw
that it has some gotchas. Like it has a CMOS mem backup battery,
which
can go bad or leak. I haven't had a chance to look at the parts
list
but hopefully it's a lithium, which don't seem to get thegrunge like
some old batteries. Back in the late '80s we upgraded over 300 ATs
with
386 MoBos, and I used to pull off the Varta mem backup batteries
that
were on the old 286 MoBos and I put 'em in a cardboard box in a
cupboard. Later, the whole bottom of the box turned brown from the
leakage and I had to almost treat them as toxic waste.

The 3478A that I bid on looke a bit beat up in the pic. I'm hoping
that
the thing's in working order. I haven't yet heard from the company,
which is supposed to contact me in two business days. I'll have to
contct them tomorrows.

It looked to me like it had one nick on the bezel, but the rest was
sticker
grunge. Sticker grunge comes off nicely with lighter fluid (VM&P
Naptha).
Mine cleaned up and looks like new... There were 6 or 7 stickers on
it.

The battery is a very long life nonrechargable lithium. I think it
will
be just fine.

If you paid Tucker by paypal or bidpay, you will probably find the
instrument
is at your door. I received no contact from them, and after 3 days I
got
curious, and emailed them. I got the package, and then I got the
reply.

Well, the auction said that if the buyer is in Tx or Calif or ?? that
they had to wait to be contacted within two business days for the final
cost, apparently because of sales tax. So I still haven't heard from
them as of this afternoon, so I guess I'll have to rattle their cage
with an email.

What's odd is that the prices are so variable. I see one go for a
hundred, another for two hundred, another for one fifty, etc. etc. I'm
wondering if the buyers know something that I don't. Like with the Tek
2235(?) scopes there is one custom chip that often dies, and it's no
longer available, so the only way is to cannibalize to get one. Or if
you're wise, don't buy the scope to begin with. Or if you bought it,
then sell it for parts. I'm concerned that I might have bought a turkey
and I'll never know it.

> -Chuck

 

[Chuck Harris]

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

Well, the auction said that if the buyer is in Tx or Calif or ?? that
they had to wait to be contacted within two business days for the final
cost, apparently because of sales tax. So I still haven't heard from
them as of this afternoon, so I guess I'll have to rattle their cage
with an email.

Just pay them using paypal. Include the CA sales tax, if you want. Your
calculator works as well as theirs. Note, you probably don't need to tax
your shipping cost.

What's odd is that the prices are so variable. I see one go for a
hundred, another for two hundred, another for one fifty, etc. etc. I'm
wondering if the buyers know something that I don't. Like with the Tek
2235(?) scopes

2465

there is one custom chip that often dies, and it's no

longer available, so the only way is to cannibalize to get one.

The 2465 is my hands down all time favorite o'scope. The problem with the
horizontal chip that blows is they let it dissipate just a tiny bit too
much power for its lack of a heatsink. If the scope gets hot, usually because
it is choked up with hair and dust, the chip dies. The easy answer is if
you get a good one, add a heatsink to that chip. I did a simple thermal
study of my 2465, and found that that one chip runs 10F hotter than all
the rest. After the heatsink, it runs cooler.

Or if

you're wise, don't buy the scope to begin with. Or if you bought it,
then sell it for parts. I'm concerned that I might have bought a turkey
and I'll never know it.

Consider this, most people are so ignorant about how to use computers that
when they finally figure out how to use a service like ebay, they still
are clueless about how to use the search function. So, what they do is haunt
the catagory that has their kind of stuff, and look through the listings that
come in every day. I am quite sure that some of these guys that are bidding
up one 3478A don't even know that there are others up for auction.

-Chuck

 

[Gary Schafer]

On Wed, 11 May 2005 19:18:56 -0700, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> wrote:

"Chuck Harris" <cf-NO-SPAM-harris@erols.com> wrote in message
news:et-dnSf5K4sUZBzfRVn-og@rcn.net...
Watson A.Name - "Watt Sun, the Dark Remover" wrote:

That didn't work, so I added www.logsa.army.mil. I got time out
error
on that, tho. I tried again just now, and again got a timeout
error.
Looks like they're blocking me, and I'll never be able to access
that
website.


click on the icon for test and equiptment publications, accept their
"terms" (believe me, you have a right to be there!), and enter a
title
search on "3478A" (caps are important!) And there it will be.

It appears to be the standard HP manual.


Looks like I'm stuck with buying one. I've seen some on CD-R, for
cheap. I wonder how good or bad the image quality is.

I suppose, that this being a binaries group, I could post the manual
for
you.

I finally got it d/l'd and posted a followup. The d/l is a standard
Army Technical Manual. No problemo, it does have the schems and PCB
layout in the back.

HP sold a hpib controlled relay actuator, HP59306A. It usually goes

for

spit on ebay. It is simple to program, and makes these kind of
chores
easy.


I found a few on Ebay for anywhere from $15 to almost $200. I
checked
out a pic of one, and it looks like it is connected to the outside
world
with a GPIB or HPIB cable. I don't have one of those and from what
I've
seen they cost major money new, and they're uncommon in the used or
surplus world.

I presumed that, if you were planning on using your new 3478A as part
of
the automation rig, you would be using HPIB.

No automation rig, just the 3478A and something else to switch the probe
leads.

I designed an HPIB controlled relay driver as part of the gear I
automated
for my thesis. It uses a few TTL chips. I can post that if you'd
like.

I found a "Kelvin Clips" 4-wire probes on Ebay, it's more than what I
paid for the 3478A! Eighty-five bucks! And that's the cheaper one!

My guess is that a couple GPIB cables will go for over a hundred total,
so I really don't see that I'm gonna save a lot by making my own GPIB
stuff. I would just as well buy a used setup if I wanted to do that
much automation. I think for now the rotary switch is as far as I need
to go.

I suppose that the thing can be actuated manually. But then I've
already got the rotary switch that I mickey moused, which works to a
certain point. And I feel real confident about its simplicty and
operation.

Yes, but that is hardly what I would call automation.

I'm not really looking for automation, I'm looking for not having to
hold the probes at a half dozen test points and change them around a
half dozen times when I make an adjustment with a pot ot two, for
esample. I think some people probably just buy a half dozen ten dollar
DMMs and connect them up to the various test points. But they aren't
all that accurate ($10 DMMs have an AC range that's 200VAC, no lower),
and the batteries run down after several hours. I'd rather use a bench
DMM that I can leave on for awhile until the circuit reaches thermal
equilibrium, for example.

I have a couple wiggle stick D'arsonval meters that I use for current
measurements, and they work okay, and take no power. But one, for
example, has a full-scale reading of 15 mA, but it has an internal
resistance of 8 ohms. And that resistance in series with the supply can
distort the performance of the circuit. So I would rather put a 0.1 ohm
resistor in series with the supply lead, and then use a sensitive DVM to
get the current thru it. I suppose that I could put an opamp with a
couple precision resistors across the current resistor to give it a gain
of 10 or 100. That way, I could use a cheap DVM to do the measurement.
But I would need 2 or 3 or 4 of these to measure the current at various
points, so it looks like the whole measurement jig starts to get too
complicated. And then there's the problem with isolating the measuring
circuits from the circuit being measured.

One example that I've run into is when I measure the current draw of a
circuit. I break the + lead and insert the DMM, and get 90mA. But when
I reconnect the circuit without the DMM, it's drawing more current, like
100mA, and putting out more power. The DC resistance of the DMM is
disturbing the circuit. So I would rather leave a low value current
sensing resistor in the + supply lead permanently so the readings don't
change with every measurement change.

Thanks for putting up with my ramblings. But these are real world
problems for which I'm trying to find solutions.

-Chuck

It is a problem when trying to measure current with a dvm. The more
sensitive the scale the more resistance the meter has. It can throw
things way off as you have noted.

I don't know how accurate you are trying to measure but also be aware
that the kind of material in your connections will make a difference
too. For example if you use steel alligator clips to a copper
connection it can generate a small galvanic voltage at the junction.
That will distort your reading. I ran into that when trying to
calibrate some meters. My readings were different every time I hooked
things up. Finally figured out it was the connections. Changed them
and things were then stable.

Be careful of the switch that you are using to switch the meter from
circuit to circuit with. Any poor contacts can have a big effect on
accuracy too.

Regards
Gary K4FMX

 

[Watson A.Name - \"Watt Su]

"Gary Schafer" <gaschafer@comcast.net> wrote in message
news:8qs6819mh6nsl7u3ji6re1hiif59ras091@4ax.com...

On Wed, 11 May 2005 19:18:56 -0700, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> wrote:
[snip]

It is a problem when trying to measure current with a dvm. The more
sensitive the scale the more resistance the meter has. It can throw
things way off as you have noted.

I don't know how accurate you are trying to measure but also be aware
that the kind of material in your connections will make a difference
too. For example if you use steel alligator clips to a copper
connection it can generate a small galvanic voltage at the junction.
That will distort your reading. I ran into that when trying to
calibrate some meters. My readings were different every time I hooked
things up. Finally figured out it was the connections. Changed them
and things were then stable.

The guy who sells those Kelvin Clips on Ebay for $85 says they're gold
plated contacts. I think I will make up a mickey mouse pair out of a
pair of clothespins. I used them for a button cell holder. I drilled a
hole thru the jaws and put two #2 screws in the holes. I filed the
heads somewhat flat to make good contact. I can use brass screws to
minimize the galvanic action. Or I could put a length of heavy copper
wire thru a pair of holes and really minimize it. I gather that it's
not a good idea to use solder because it's also a bimetallic junction.
I have some flexible 5-wire cable that should make a good test lead.

Be careful of the switch that you are using to switch the meter from
circuit to circuit with. Any poor contacts can have a big effect on
accuracy too.

I had to squirt contact cleaner in the switches of the 30+ yr old PSes
that I got. But I'm not really worried about accuracy. I just want to
get something together that'll allow me to monitor a few points for V
and I and allow me to calculate power in, power out and efficiency.

Regards
Gary K4FMX

 

[Watson A.Name - \"Watt Su]

"Gary Schafer" <gaschafer@comcast.net> wrote in message
news:8qs6819mh6nsl7u3ji6re1hiif59ras091@4ax.com...

On Wed, 11 May 2005 19:18:56 -0700, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> wrote:

"Chuck Harris" <cf-NO-SPAM-harris@erols.com> wrote in message
news:et-dnSf5K4sUZBzfRVn-og@rcn.net...
[snip]

I just wanna let people know what's going on with these seemingly
clueless people at teoutlet (Tucker).

I won the bid on the 3478A, and as the instructions in the bid said, I
waited for two days for them to contact me. Well, I didn't hear from
them, so on the third day I did "ask seller a for the total price" and
they replied back that it was $75 plus $16 shipping, total $91. So I
paypaled them $91.

Then I get back this message that they have a sales presence in Calif so
they have to charge me 7.75% tax. So please send them $7.05. Well,
DUH! They said exactly that in the auction, and that's why I waited for
them to contact me with the total price. And when I asked them for the
total price they told me $91 total, no tax. So why didn't they say so
then, instead of after I paypaled them? Duh.

But then I figured out that they were charging me $7.05 tax on both the
item and shipping. So I replied to them that the shipping wasn't
taxable and that I would paypal them 7.75% of the $75, or $5.81 if that
was acceptable. So I expect to get a reply back tomorrow with the
correct amount. But then one never knows since they have been nearly
clueless up to this point. :-?

 

[Winfield Hill]

Watson A.Name - \"Watt Sun, the Dark Remover\" wrote...

... But then one never knows since they have been nearly
clueless up to this point. :-?

Sheesh! I have done over 2000 eBay transactions and have met
many clueless eBay sellers. But what you describe above hardly
fits the definition of clueless, as I have come to know it.
In point of fact, Tucker is one of the better eBay sellers.


--
Thanks,
- Win

 

[Watson A.Name - \"Watt Su]

"Winfield Hill" <hill_a@t_rowland-dotties-harvard-dot.s-edu> wrote in
message news:d621a70nla@drn.newsguy.com...

Watson A.Name - \"Watt Sun, the Dark Remover\" wrote...

... But then one never knows since they have been nearly
clueless up to this point. :-?

Sheesh! I have done over 2000 eBay transactions and have met
many clueless eBay sellers. But what you describe above hardly
fits the definition of clueless, as I have come to know it.
In point of fact, Tucker is one of the better eBay sellers.

I'll have to agree with that. The last transaction I did, the ol' HP721
(like the one you bid on and won) came with a bad main filter cap (it's
probably 40 yrs old). It took me three emails just to get the seller
(obviously trying to avoid responsibility) to reply back, and more than
a half dozen to resolve it (I got a partial refund).

And then there are the outright liars that I've had to deal with. The
Consumer Sentinel http://www.consumer.gov/sentinel/ says auction fraud
is their largest complaint category, with 1/6 of all complaints.
http://www.consumer.gov/sentinel/2004%20Reports/sentinel%20top%20complai
nt%20categories.pdf
Indeed, I've had to deal with several bad sellers, and I've only done a
few score transctions. Sad, really.

I've read that you should run, don't walk, away from a seller that has a
feedback rating of below 98%. But I've found that reading the bad
feedbacks gives an insight into the mindset and attitude, bad or good,
of the seller.

One burning question is, what do I do if Tucker insists that I pay taxes
on the shipping? Do I pay it and file a complaint with ebay? Or not
pay it, and hold up the tranaction? Ooh, today is Friday the
Thirteenth. Ominous. I hope it's not going to be that bad...

--
Thanks,
- Win

 

[Chuck Harris]

Watson A.Name - "Watt Sun, the Dark Remover" wrote:

One burning question is, what do I do if Tucker insists that I pay taxes
on the shipping? Do I pay it and file a complaint with ebay? Or not
pay it, and hold up the tranaction? Ooh, today is Friday the
Thirteenth. Ominous. I hope it's not going to be that bad...

First off, I don't think they will. If you don't get satisfaction with a
simple email, call them. They are good folk. I don't like the quality of
their repair work, but they go out of their way to please.

In the event that they are having a bad day, and they insist on taxing the
shipping, pay it. We are only talking about $0.30. They have done a hell
of a lot for your $95. You are getting a tested instrument, a foamed-in-place
box, and a copy of the operators manual. Look at what the others are giving
you for 50% to 150% more.

Tucker is a very respected, well known entity; that is why I made a point of
aiming you at that auction. It worked just the way I hoped it would.

Smile, be happy.

-Chuck