Welcome to the Home Page of Chuck Adams, K7QO

This page updated July 8, 2017.

Radiative Transfer Physics

This section contains research work that I have done over the past 50 years. Time flies when you are having fun.

  • Chandrasekhar's classic text on Radiative Transfer Book in PDF format.

    I read this book when starting work on a masters degree in physics. Picked the invariant imbedding chapters to do my thesis. The purpose was to replace the Coulson et al book with tables for a Rayleigh atmosphere with more accurate and stable numerical results.

    Invariant Imbedding

    Here is the published paper and the codes for the results for an Invariant Imbedding solution for a Rayleigh plane parallel atmosphere. Found a copy of the article on the Internet.

  • Solutions of the Equations of Radiative Transfer by an Invariant Imbedding Approach. Paper by C.N. Adams and G.W. Kattawar. 1970.

  • FORTRAN code for scalar results for a Rayleigh atmosphere. My FORTRAN code for scalar radiation.
  • FORTRAN code for vector results for a Rayleigh atmosphere. My FORTRAN code for vector radiation (Stoke's Parameters).
  • Data set for Rayleigh atmosphere. Data set to generate several optical depths up to tau of 10.
  • Data output for Rayleigh atmosphere. Computational results for the scalar code rt01.f
  • Data output for Rayleigh atmosphere. Computational results for the vector code rt02.f

    To reproduce the results on a Linux system with gfortran installed.

       gfortran -fno-automatic -o rt01 rt01.f
       ./rt01 < 001  > 001.scalar.out
       gfortran -fno-automatic -o rt02 rt02.f
       ./rt02 < 001  > 001.vector.out

    These two codes were the first programs that I ever wrote in my life. Done on an IBM 360/50 using FORTRAN IV compiler. I was a summer intern at Texas Instruments in Dallas TX. We had two IBM systems in a duplex mode. I was given use of one of them for 12 hours on a Friday night to run both programs and it took most of that time. O/S was the old PCP (Primary Control Program) before HASP (Houston Automatic Spooling Program), so jobs were loaded using decks of IBM hollerith cards. Those were the days. Now both codes take less than 2 seconds total for runs to larger optical depths than published in the paper.

    rt01.f is commented and rt02.f is not. Maybe, some day, I'll come along and do the work. Until then use both codes and compare the comments, if you are interested in the details of the code. The no-automatic option is required because the original IBM FORTRAN compiler used static allocation of memory and not call by reference, thus one of the calls generates a local variable and the results are not passed back to the main routine. I just haven't modified the code yet and I have to spend some time locating the minor problem. My preference is to rewrite everything in C.

    Backward Monte Carlo Simulation in Plane Parallel Atmospheres

    Here are two papers I have written up on how to do backward monte carlo simulation of photons scattering in an atmosphere by starting at the detector instead of the energy source. Thus the name backward monte carlo. Results are compared to the benchmark in the previous section using invariant imbedding.

  • Backward Monte Carlo Simulation with Scalar Radiation. How to write a computer program in C for photon simulation. (rt08.c)
  • Backward Monte Carlo Simulation with Vector Radiation. How to write a computer program in C for photon simulation with polarization. (rt10.c)

    The K7QO Code Course CD

  • K7QO's Code Course 4.0 CD in ISO File Format See manual.pdf for guide to course.

  • K7QO Sending with MFJ Dual Lever Paddle

    Electronic Devices and Circuit Theory

    My freshman year of high school. Something happened that has caused me problems ever since then. In algegra 1, Tabor Rowe (the teacher) had us pick the problems we would work at the end of each chapter and turn in the list the first week. Each student did his/her own list. I turned in the list, but I was having so much fun doing the problems that I did them all at the end of each chapter. The same year, Mrs Mildred Howard taught us penmanship and would not allow us to use anything other than a fountain pen for writing. We all bought the old Big Chief writing tablet and practiced penmanship for six weeks after school. To this day I still write with a fountain pen. Did all my homework in ink through a bunch of college degrees. Bugged the hell out of math instructors. :-)

    From time to time I love to take a book and go through it. This year it is circuit theory. Had one course at MIT on the topic, but not a detailed course like the two books below. So I'm picking one and going through it. Won't be doing all the problems. Too many and time is short. Goal is to work two chapters a week. Start at the beginning and go to the end. (Alice in Wonderland line.)

    I thought you might be interested in following along on a circuits course. There are two textbooks written by Boylestad and another by Paynter. Don't know which is better. Way to find out is look at them. Let's start with Boylestad first. Two chapters per week for starters. March 20th is the first day of spring. Let's grow something. Our knowledge of the Universe.

  • Electronic Devices and Circuit Theory The 11th edition.

    And here is a copy that you can read online without having to download.

  • Electronic Devices and Circuit Theory The 11th edition.

    And if you won't cheat but work the problems first before checking your answers, here is the solutions manual to the 10th edition, so not all problems, but a lot..

  • Electronic Devices and Circuit Theory Solutions Manual The 10th edition solution manual.

  • Introductory Electronic Devices and Circuits Scanned book of Paynter's book. (large file of about 120MB)

    Here are the chapter titles for each book for comparison. I like the Paynter book as there are some chapters that will lead into some ham radio transceiver design discussions later. IMHO.

    Introductory Electronic Devices                         Electronic Devices and Circuit Theory
        and Circuits 6th Ed                                            Seventh Edition
    Robert T. Paynter                                       Robert Boylestad and Louis Manhelsky
    1010 pages  2003                                        934 pages
    -------------------------------                         -------------------------------------
     1 - fundamental solid state principles                 1 - semiconductor diodes
     2 - diodes                                             2 - diode applications
     3 - common diode applications:                         3 - bipolar junction transistors
         basic power supply circuits                        4 - dc biasing -- bjts
     4 - common diode applications:                         5 - field effect transistors
         clippers, clampers, voltage multipliers            6 - fet biasing
         and displays                                       7 - bjt transistor modeling
     5 - special applications diodes                        8 - bjt small signal analysis
     6 - bipolar junction transistors                       9 - fet small signal analysis
     7 - dc biasing circuits                               10 - systems approach -- effects of R_s and R_L
     8 - introduction to amplifiers                        11 - bjt and jfet frequency response
     9 - common emitter amplifiers                         12 - compound configurations
    10 - other bjt amplifiers                              13 - discrete and ic manufacturing techniques
    11 - power amplifiers                                  14 - operational amplifiers
    12 - field effect transistors                          15 - op amp applications
    13 - mosfets                                           16 - power amplifiers
    14 - amplifier frequency response                      17 - linear-digital ics
    15 - operational amplifiers                            18 - feedback and oscillator circuits
    16 - additional op amp applications                    19 - power supplies (voltage regulators)
    17 - tuned amplifiers                                  20 - other two-terminal devices
    18 - oscillators                                       21 - pnpn and other devices
    19 - solid state switching circuits                    22 - oscilloscope and other measuring instruments
    20 - thyristors and optoelectronic devices
    21 - discrete and integrated voltage regulators

    After doing some of Boylestad, I have decided that I will be doing Paynter instead. You can do Boylestad, since there is a solution manual. Paynter has answers at the end of the chapters.

    Equation 2.3 in Paynter is wrong. Completely wrong. Look at it and see if you can figure it out. Then go to your browser and google for 'precentage of error' and look at the top of the page. The correct formula is PE = (x - x')/x' * 100 %. Where x is measured value and x' is the calculated value using correct and complete analysis. This means that there are several generations of students that will be doing it wrong. Some one should have caught this decades ago. I will be using the correct formula throughout the book.

    You do the problems first without my help or looking at the answers in the book before completing what you think is correct. Double check, then look. I will be working through the problems in the same manner. I will not have the following checked until I finish all the problems I want to work. I will check afterwards and you will know I have done this when you see the next chapter solutions posted. This means that this is work in progress until I go to the next chapter. It's my walk down the road. :-) Enjoy and learn something today and every day. Life is short.

    Some one is going to email asking about the spacing. I have not tried to get as many problems solved per page as I can. I'm not trying to waste paper, our number one renewable resource in the USofA. About 17 years ago, when we moved from Dallas to Prescott, Staples had notebook paper sales just before the start of each school year. They sold 500 sheet packages of college lined notebook paper for twenty-five cents a package. Needless to say I recognized a deal when I saw one. Have a stack of unopened packages over 1 meter high. I want to use it all up before the estate sale. :-) This project will help. I have a fountain pen from China that I paid less that two bucks for and item number 1645538849018 on ebay.com for 2 liters of ink to use. I'm going for the brass ring. My guess is that fountain pens are so cheap because there is no demand for them any more. A friendly environmental tool, 'cuz you don't need but one pen that you can continuously refill until you wear it out, which I have never done in my lifetime.

    In the 6th edition there is an error in equation 2.3. It looks like the book uses the correct formula in the working of the problems. Here is a reference for you to compare (2.3) to the correct formula.

  • (2.3) correct formula

    OK. For some solutions I found that I scanned them and posted them and then checked the answers with those in the book and then found a calculator error. My bad. Rusty at using the calculator. Thanks to computers. It is not worth my time and effort to go back and rescan, so just beware that a couple of problems are off on the answers.

  • Chapters 1 and 2 Notes and Solutions for Paynter's book. Mar 26, 2017.
  • Chapter 3 Solutions for Paynter's book. Mar 30, 2017.
  • Chapter 4 Solutions for Paynter's book. Mar 30, 2017.
  • Chapter 5 Solutions for Paynter's book. Apr 3, 2017.
  • Chapter 6 Solutions for Paynter's book. Apr 4, 2017.
  • Chapter 7 Solutions for Paynter's book. Apr 16, 2017.
  • Chapter 8 Solutions for Paynter's book. Apr 24, 2017.
  • Chapter 9 Solutions for Paynter's book. May 2, 2017.
  • Chapter 10 Solutions for Paynter's book. May 5, 2017.

  • K7QO Lab Notebook Version 6.30 My lab notebook. June 27, 2017.

    Use qrz.com to find my email address using K7QO.