Preferred calculators for EE use
 

Leaving aside the little sliderule that I used as a child, the larger ones
latter, and the huge spiral job at University, I started with a desk top
Burrows (sp?) with nixie tubes and lots of RFI (still have it). In 1972
when the HP35 was announced, I bought two. One for my wife to use. They
were so expensive that we had our names engraved into the case. Still have
them and they still work.
The HP25C was nice, the HP15C was near-optimum (and still kept as a
backup), but I find the HP48 series to be the most useful. I keep one at
work and one at home and at least one new-in-the-box. As Roy has indicated,
the HP48 does an excellent job with complex numbers including solving
systems of linear equations with complex coefficients. The HP48 also allows
the easy storage of non-linear equations with many variables and allows one
easily to solve for any one variable. I have not used more than a few % of
the calculator's capability. Only one faculty member in my ECE department
uses other than an HP calculator (a young instructor).

For some time, I used the HP calculator with a built in printer and
magnetic card reader. Cannot remember the number. I did use its
programming capabilities. One program that I wrote - to get in the
obligatory antenna reference - was a program to estimate the bore-site gain
of a rhombic antenna - HP published it in one of their many books.

My students are required to master the use of a calculator in circuits
and electronics. The HP48, and now the HP49, is the best for those
purposes. However, many students limp along with TI calculators. Some of
them do not have ready access to a reciprocal key. Try finding the
impedance of three impedances in parallel without a reciprocal key. With an
HP48/49 the task is trivial.
The ability with one stroke to combine an imaginary part with the real
part of a complex number is an example of how well suited the HP48 is to EE
work.

As part of my syllabus, I give examples of the type of calculations that
the student's calculator must be able to perform. Because discerning
students now purchase HP49 calculators, I also have one of them. Seems not
to be as rugged, but it is much faster.

I can not speak to the programming system of the HP48 as I have not used
same - though the solve scheme of complicated equations gets a regular
workout. Swapping is effected with two key strokes: (0,0 column, row
starting in the lower left) 0,3 and then 6,8.

It was always clear that when the engineer founders of HP left, the
company would flounder. Thank goodness much of the important part was spun
off.

The answer to the original question: buy an HP49 - spend some quality
time learning to use it. In terms of purchasing cost, an HP49 is very low
cost compared to a good slide rule.

73 Mac N8TT
--
J. Mc Laughlin; Michigan U.S.A.
Home:

"Roy Lewallen" wrote in message
...
I also started with an HP35, then 45, and went from there to an HP41CX.
That was the nicest calculator I've ever had, and I flat wore it out. I
was late getting a PC, but put the 41 to use in solving everything from
iterative network problems to antenna patterns, self and mutual
impedance calculations, phased array feed systems, you name it. The
functions I most used were right there on the keyboard, available with a
couple of keystrokes at most. Programming with the assembly-like
language was fast, easy, and to me, intuitive. I ended up with a very
large library of programs of all kinds.

Its replacement, an HP48GX, is a disappointment in every way but one.
The person or people who dreamed up the programming system were totally
indoctrinated, like so many of today's software engineers, that object
oriented programming (OOP) is the best and only solution for every
possible problem. Consequently, creating even a simple program is
terribly time consuming and the result is worse than the worst GWBASIC
spaghetti code I've ever seen. It's horrible! And while it can be highly
customized, the learning curve is steep. Without customizing, just
changing the number of displayed decimal points from 2 to 3 involves 5
keystrokes and waits of several seconds. I still don't know of a quick
and easy way to swap the values in the x and y registers, although I
honestly haven't looked hard and am sure there's a moderately simple way.

Its single redeeming feature, which keeps me using it daily, is the
facility with which it handles complex numbers. I can mix and match real
and complex numbers, add, multiply, take the square root, trig
functions, everything, just as easily as with purely real numbers. I can
swap between viewing in rectangular and polar notation in a second, and
enter complex numbers in either form. For the kind of calculations I do
very frequently, it's terrific. But if I didn't do a lot of calculations
with complex numbers, I'd give it a 0.5 on a scale of 10.

Roy Lewallen, W7EL

Tom Ring wrote:

In order, I like my HP15C, HP11C, and way behind HP48SX. And then there
is my HP25.

I originally purchased an HP35, then an HP45, then an HP25, then finally
an HP11. Which was so tough it got run over by a NY DOT dump truck and
had merely a crease above the LCD display. And is still in use 25+
years later.

I purchased the HP15C as new when I thought the 11C was lost.
Fortunately it was not. So I ended up with both (eventually).

I purchased a 48SX at a hamfest for $75. It seemed a good deal at the
time, although I had to wait about a year for the heavy tobacco smoke it
had absorbed to dissapate.

I still like my 15C the best. And it is still on it's second set of
cells since 1982, impressive.

-----------------------------------------

So, what calculators do you like best?

And, of course, why.

tom
K0TAR

Preferred calculators for EE use
 

"Tom Ring" wrote in message
. ..

In order, I like my HP15C, HP11C, and way behind HP48SX. And then there
is my HP25.

I originally purchased an HP35, then an HP45, then an HP25, then finally
an HP11. Which was so tough it got run over by a NY DOT dump truck and
had merely a crease above the LCD display. And is still in use 25+
years later.

I purchased the HP15C as new when I thought the 11C was lost.
Fortunately it was not. So I ended up with both (eventually).

I purchased a 48SX at a hamfest for $75. It seemed a good deal at the
time, although I had to wait about a year for the heavy tobacco smoke it
had absorbed to dissapate.

I still like my 15C the best. And it is still on it's second set of
cells since 1982, impressive.

-----------------------------------------

So, what calculators do you like best?

And, of course, why.

tom
K0TAR


I started with my name engraved on a K&E Log Log Duplex Decitrig. But that
was over 20 years before I bought an HP35. When the programmable HP65
appeared, I was in heaven. I bought every solutions book and even wrote and
submitted a few myself. Of course the HP67, HP41CX and HP42S saw steady use,
each in its day. When the HP48GX came out, I eagerly snapped one up, and
after about a week of frustration I wrote a terrible letter to HP, decrying
their "start over with a blank sheet of paper" approach. I guess those are
the 4-bangers one of you mentioned above. After retiring from my engineering
position, I found quite a few HP12C at various flea markets, and snapped
them up - - you need a calculator at every desk, coffee table, and work
bench in the house and every car in the garage, don't you? But then, an
amazing machine hit the (flea) market - - the HP17B, and its so welcome
follow-on the HP17BII with Reverse Polish and "solve" functions. Of course
there were HP27S, HP11C and an HP15C found at various times, too, but
currently the HP12C at every elbow, and at my main computer table the HP42S
for complicated things like Log Periodic antenna design, and Solar Array
calcs and my trusty HP17BII for all single expression solutions. It has been
an eventful and enjoyable life.

Chuck W6PKP

Preferred calculators for EE use
 

Prior to 1972 I used a K&E and then a Pickett & Eckel slide rule and a Smith
Chart calculator slide rule.

But I purchased an HP-35 when it first came out. Then the HP-45, and a 55 that
had a neat timer. After retiring in 1980 I purchased the HP-34C and the 15C. One
of my sons worked for HP for 25 years, and while there he purchased two HP-42S,
one for me. They all go with me wherever I go.

I tried to use someone elses TI one time, but after using RPN I couldn't make
the darn thing work. The RPN works just like writing down the problem and
solving it with a pencil.

That Polish guy Lucashowicz (sp?) is my hero!

Walt, W2DU

Preferred calculators for EE use
 

I generally leave my HP48 in the lab... so that leaves me using Google
Calculator all the time ;-) I'd forgotten that the HP48 is good with
complex numbers so I should probably start carrying it home...

Google Calc is useful in that it knows units, and it knows many the
fundemental physical constants... so you can do all sorts of cheating.


Throw this into the Google search box:

1/(2*Pi*4MHz*50 picofarads)

or try:

0.625*(c/14.030MHz) in feet

73,
Dan

Preferred calculators for EE use
 

Preferred calculators for EE use
 

Fred McKenzie wrote:


I do have a Palm PDA. There is a freeware reverse-Polish program for it
called Kalk by Holger Klawitter. It is available at
http://www.klawitter.de/palm. I doubt it will match the fine HP
instruments you mention, but you may want to have a copy if you spend a
lot of time with your PDA.

73,
Fred
K4DII

On my Palms I use MathU Pro. Looks like an HP calculator, although one
that has never been made by HP. Works quite well. It is not free, but
is very cheap.

tom
K0TAR

Preferred calculators for EE use
 

Walter Maxwell wrote:


I tried to use someone elses TI one time, but after using RPN I couldn't make
the darn thing work. The RPN works just like writing down the problem and
solving it with a pencil.

That Polish guy Lucashowicz (sp?) is my hero!

Walt, W2DU

I have the same problem. I either make stupid mistakes or just plain
can't use non-RPN calculators.

tom
K0TAR

Preferred calculators for EE use
 

Tom Donaly wrote:

Instead of dragging your calculator home all the time, why
not go to hpcalc.org and download an emulator program for
your PC?
73,
Tom Donaly, KA6RUH

My calculator is lighter and more portable. :)

tom
K0TAR