Remote HF and Maximum Permissible Exposure (MPE)

by Jon Crisman, W0JEC

Newly rewritten Remote HF Station and Antenna Control software Now includes a dedicated TCP client and server to greatly simplify installation and operation.  Virtual Com ports and the use of a separate TCP client are no longer required!


Newly rewritten MPE Calculator now runs on all Windows operating systems.


What’s Included On This Website


This website offers details and downloads of two ham radio projects I have undertaken.  The first project concerns HF Remote — the operation of my HF station remotely from my laptop wherever I have access to the internet.  To do this, I have selected the free software Ham Radio Deluxe to remotely operate my two HF radios, and the very inexpensive software PstRotatorAZ to remotely operate my Hygain Antenna Rotator.  Somewhat more challenging was a means to remotely control my LDG DTS-6 antenna switch and turn on and off my backup HF transceiver and other station accessories.  For this, I designed a circuit board utilizing the Picaxe microcontroller chip by Revolution Education and wrote the microcontroller software to program the Picaxe chip. Next, I wrote the Visual Basic 2010 software (W0JEC Station-DTS Control and W0JEC Server) to access and control the chip remotely from my laptop.  All of this — the circuit board, microcontroller command file, the W0JEC Station-DTS Control program, and detailed setup and operating instructions are offered free for download from this website.  For those who do not own a DTS-6/4 antenna switch, I also provide similar free software, schematics, and instructions for remote station and antenna control using a homemade antenna switch. Just browse through the web pages using the content menus to find information about each of the HF Remote devices and software. Enjoy. 


The second project, MPE Calculator (Maximum Permissible Exposure Calculator), is a newly rewritten version of a calculator program I wrote a number of years ago for Windows 95.  The new software now runs on all of the current Windows operating systems.  The program provides a calculator that you can use to determine if your station meets the FCC requirements for RF safety.  After entering your station and antenna configurations (transmit power, feedline, and antennas), the software will calculate safe distances that must be maintained from your antennas for each band and operating mode according to the FCC guidelines.  You can also calculate RF Power Densities for each station configuration (required for evaluating multiple antenna sites.)  Reports of the MPE evaluations and power density calculations can be saved for later printing as permanent records of your evaluations.  The MPE Calculator web pages describe the FCC guidelines regarding RF exposure safety and the procedures for evaluating your ham station to determine if you meet these guidelines.  A free download of the software is available on the Downloads page. 



Jon Crisman, W0JEC


      I am a retired hospital administrator and presently teach microbiology at Bemidji State University in Bemidji, MN.  I was first licensed in 1972 and hold the Extra Class license.  I built my first computer, a Heathkit H89, in 1980 and wrote my first computer program in assembly language for that computer.  Since then, I have dabbled in electronics and computer programming and enjoyed the ham radio hobby.  In ham radio, I especially enjoy building antennas, helping to maintain the local radio club’s repeater network, working contests (especially Sweepstakes and CQ SSB WW), and working with county emergency management providing ham radio communications support.