Must have tools for circuit testing bench 12

[machmech]

Hello Folks

I am curious and would like to see a short and simple list,( I will research the options) or ask questions regarding preference if necessary.

Basically, What are your favorite and or must have tools on your work bench? Just in case it is inappropriate to mention name brands (I don't want to advertise or offend anyone) we can refrain from this, Those in the field know what is quality . Although Minimums and maximum requirements are good.

Your input is appreciated

Thanks, Chuck

 

[itsmoked]

machmech; The 32S is ummmm, sublime to use. It is very fast to use. It's logical and is fast for switching back and forth between hex and decimal which is good for embedded design and software work. And it is RPN!! Once you figure out RPN you never want to go back to arithmetic calculators.

I got mine in the 80's for $90 bucks. I then gave it to my son for his school work. I purchased HP's latest, which a few years ago was the HP48G. I truly hate the 48. It is the most cryptic illogical calculator I have ever seen. It took me several days on forums to figure out how to even convert a number between hex and decimal. To save a value in memory takes so many steps I can't remember them. I still use it but I don't like it. I finally decided I wanted another HP32. I got one on EBay $100, only to realize it was a 32 of a lessor species maybe not a IIS. I traded my son for the IIS and am again a happy camper.

Short history of the calculator:
Hp came out very early with their RPN offerings. They were functionally better than anything else out there. They felt better, the buttons were better and they were always intuitive, always a cut above. I got an HP64 in college that used magnetic cards to store large programs. It was awesome. I could write programs to figure out transmission line problems and other complex solutions. I'd run those mag cards thru it before a test and get some nasty glances out of my class mates. Eventually some numskull at HP decided
that making the finest calculators in the world was a pointless endeavour. (cripes) HP divested itself of calculators sold the line to some NZ or Ozzy group of people including the HP people. They tried to continue the line with no resources. They brought us the HP48g and then a newer versions whose buttons were so bad the calculator was a disaster. They abandoned hot stamped buttons for painted ones that promptly wore off. Last I heard they suspended all further development and were sinking into oblivion.

I just looked and see that HP carries HP calculators now! They have a couple (3?) calculators that look like the typical Casio fair. Only one is RPN. Very sad that no one at HP could look ahead and recognize the need or market for high end calculators and just stick with the originals. Why they took something generally considered perfect and kept trying to improve it is a testament to modern corporate dysfunction. Akin to trying to continually improve the desk ruler.

Well that was probably more than you were looking for but as you can see it holds a deep emotional spot in my heart. If my HP32IIs choked I wouldn't hesitate to drop $300 to acquire a replacement.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[ScottyUK]

Does anyone know if the circuit drawings for the old Heathkit designs are still around? I have an old linear power supply which provided pretty good performance. From memory it was 50V / 1.5A and had about 10 switchable ranges of about 5V per step with a fine adjustment within each range. Some of the semiconductors have passed away, and the chassis wiring is awkward to bell out to make my own drawing, although that is a last resort. It has a degree of sentimental value too, so I don't want to throw it out.

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I don't suffer from insanity. I enjoy it...

 

[itsmoked]

My main bench-top logic supply is a Heathkit. 5V@1.5A and plus and minus 0-20V. Works great.

I would guess a wad of googling might work. Someone might be able to help. How about some AARL forum?

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[machmech]

Hi Keith

Thank you for a well written response, you obviously have experience in this field and apparently your not alone, I started a search for a comparable model and found a customer review which is very good and does outline and confirm your disappointment in the functions of a next gen model.

http://www.calculator.com/shop/item.php?m=electronics&s=scientific&ASIN=B0000DK6G9

I have a friend who is a retired Engineer from Zenith and he still holds his calculator near and dear although he no longer gets compensation for his work he loves it when I ask for help and will hash out a problem and explain things to me in detail. I believe math was his favorite part of the job.

Thanks, Chuck

 

[OperaHouse]

Scotty, Most of the HEATH KIT line in available at

http://www.bama.sbc.edu

in deja whatsit format for FREE (they have a free rader). The scans I have seen are quite nice, even color for the cover!

I have an old HP desk top calculator with a CRT. It is so slow that they have a solenoid to lock the keyboard till the calculation is done. Memory is a delay line made from a long cable. Still works, but the scren is a little wavey from the old caps.

 

[ScottyUK]

Operahouse,

Thanks for the tipoff - I'll have a look.



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I don't suffer from insanity. I enjoy it...

 

[ScottyUK]

Link should be

http://bama.sbc.edu

What a useful site!


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I don't suffer from insanity. I enjoy it...

 

[OperaHouse]

A site you might add to that is

http://www.d8apro.com/heath3.htm

which is a cross reference of HEATH semiconductor part numbers.

 

[Skogsgurra]

Operahouse!

That old HP wouldn't be an HP 9100A, would it?

I have a very special feeling for that one. I am prepared to swap my HP 35, the first HP pocket calculator. Still working...

Tell me! Tell me! Tell me!

Gunnar Englund

http://www.gke.org

 

[ScottyUK]

Opera,

I've got my manual for my PS - it's an old IP-27. You've made me very happy today. Thankyou.


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I don't suffer from insanity. I enjoy it...

 

[OperaHouse]

That IP-27 is a pretty nutty circuit. Current limiter is one big PNP germanium seperate from the voltage regulator. I have one I want to sell on ebay (they still bring $50-70). I got mine working over a year ago, but I find the cover! The HP is in storage, I'll have to dig it out.

 

[ScottyUK]

Yeah, I've just been looking at it. I now realise why I made little headway trying to sketch the circuit by tracing the chassis wiring: what a peculiar circuit design. I didn't know 15A germanium transistors existed! I think if D7 is replaced by a series pair of silicon diodes and with some judicious changes to the sense resistors it should be possible to use an MJ2955 or similar silicon transistor. The electrolytics all need replacing too.

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I don't suffer from insanity. I enjoy it...

 

[panelman]

When I started work the physics department of a british university had ONE calculator. That was a RPN HP and was so valuable it was fixed to a bench with a big steel cable

Today my toaster has more computing power

 

[jimkirk]

When I was in college a friend of mine had an HP45 calculator that was being borrowed a lot. He took it apart and swapped the "sin" and "cos" chicklet key tops. Borrowing fell off dramatically. Another lesson in knowing roughly what to expect in a calculation, and recognizing when an answer doesn't make any sense.

 

[richs]

Hi all-

I'm surprised that you haven't inlcuded jumper wires as part
of the "must haves". Even the cheap Radio Shack with
alligator clips are always a keep around. For me, a 1 gallon
zip lock baggie with my collection. Keeps them all easily
transportable.

The thread has been to power supplies. One of the most common
power supplies that I reach for was an oldie I built in
college, 5V 1A 'er, with a 7805 (a TO3 can with a copper base!)
The old beastie is just right for prototyping. It's in a
2X2X4 bud box. Variables done with the 3 terminal regulators
in a duplex electrical box (aluminum boxes are getting
expensive these days!

Wall worts can be a good friend as well. We have a local
surplus electronics store where there is a whole isle full
of them. Wander down and for a $1 or 2, you can find either
one that you can use directly or again, a 3 terminal
regulator. I find that I'll put a series switch in there
as I don't like to plug and unplug. A little bare board
with 3 way binding posts. Sometimes with an LED for
power (usually not). If not blessed with an electronics
store, try Good Will or Salvation Army. Usually the
voltage is right on the wort. Very handy to have around.
And a lot less sheet metal work!

I find that test equipment for me is usually done on an
as needed basis. However, if I'm tired of working on what
is in front of me, I'll tackle a little side project.

Wacking out a little power supply or the like, for a couple
of hours when there's nothing on TV can be satisfying.

DMM's- Cheapies. Usually no more than $7.00. Harbor
Freight now sells cheap ones for $2.99. Shoot, for that
price, you can buy them by the dozen! The make vs. buy is
pretty clear cut on that one. Just remember to turn them
off when finished so you don't run down the batteries.

Logic probe- Here again, the make vs. buy. I built my
first logic probe, but the packaging wasn't as good as the
cheap bought ones. So, that was a $17.00 investment. If
you have electronic flea markets around, you might wander
across a old HP logic probe. Very nice, but watch out for
the sharp tip!

Function generator- Here was a make vs. buy that went to
make. An XR2206 3 wave chip with the app note does a fine
job for me for low frequency function gen. An emitter
follower for the square wave output to directly drive TTL
logic was needed, but other than that, it's been a usefull
tool. I built it in a 4 way electrical duplex box with
a plastic front cover. Here again, it was a nice diversion
from the task at hand.

Tek 375B scope.- Took a chance on eBay and bought one for
under $400.00. This was the same type as I cut my teeth on
many years ago after college and still a favorite of mine.
Got real lucky and the "cal'ed" was indeed done on it.

Frequency counter- This was a make. Did it as an exercise
for PIC development. Still need to do a decent analog front
end. Prescaled to 100MHz, 8 LARGE LED display (my eyes
are getting old). And still have to put it in a case. I
don't use it all that much, so with a wall wort power supply, and a couple of wires,
the bare board hangs out there
on the bench........ There are several designs out there
on the internet that can be used if you want to go this
route.

Good soldering station- I've used Weller all my life at
work,
however, nowadays there are some reasonable Chinese ones out
there on the market. I took a change and got a temp.
regulated one recently and was quite pleased with the results!
Not bad and 1/3 the cost of the Wellers. Bought many spare
tips as these might be a problem replacing in the future.
My old Weller (made up of broken parts of other ones that
were piece replaced at work) now sits collecting dust.

Logic analyzer- Here was the second major investment in test
equipment for me. Recently looked at the problem. Usually
clients have one that I can use. Last client gave me a brand
spanking new Agilent scope/16 channel analyzer. Runs a
built in PC with XP. First time I had a scope that I had
to worry about malware! Left the LAN connection unplugged.
But, if it's coming out of *MY* pocketbook......

I do a lot of embedded processor work. Logic analyzer is
REAL nice to have. But, I'm not spending +$5K! Did a
little research and my choice was an Intronix, USB link
one. YMMV, but it's nice to have it conneted to an old
laptop on the bench. $400.00 works as advertised. Real
pleased with it and it has justified it's expense many times
over.

One or more (usually more) old PC's kicking around. Usually
running a dual boot linux/windows. Usefull for logging
data from rs232 inputs, complex waveform generators, etc.
USB interface for logic analyzer, programmers, etc. 300-500MHz
machines are fine with linux.

Itsmoked did it to me! O.K. I'm going to
replace my old Heathkit (Griefkit) Grid Dip Oscillator with
a home built gate dip one! There we go! A little PIC
microcontroller for an LCD frequency display, battery
operation. Cool! The summer reruns are coming on the tube
pretty soon. Should provide hours of fun.

Luddites unite!

Cheers,

Rich S.

 

[machmech]

Thank you rich

Awesome list with some interesting tech tips to boot!
About that last paragraph LOL That Keith dude is a bad influence.

Chuck

 

[itsmoked]

Muwahahahahaaaaaaaaaa!


Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Warpspeed]

But you guys have failed to mention the one "must have" for doing any kind of electronics work:

A COFFEE MUG

No electronics workbench is ever complete without one.

 

[circuit1952]

Warpspeed, I've been tempted to spec a coffee mug holder on some equipment we've ordered!

 

[machmech]

Ceramic is a good insulator!