Dear Board:

ARRL published the first edition of my book “Antenna Zoning for the Radio Amateur” in 2001 (20 years ago). At that time, I felt that it would be useful if a ham applying for a permit could show the neighbors and any authority, like a Planning Board or Board of Appeals, that the proposed project would not fry any eyeballs. Also at that time, I asked Ed Parsons, K1TR, then working at AT&T Labs in Andover, MA, if he could create a program that we could use in the advocacy for all necessary tower permits.

He followed the OET-65 formulas, and I wrote the text.

Since then, I’ve asked VE6SH to find a Canadian engineer who likes to find faults in others, and he did so. That engineer reported back to Tim that the program was fine. Similarly, I asked N6AA to look at it. He too reported no problem. I recently asked Matt Butcher, P.E., to look at the text.

The Third Edition of the book will include:

Thank you Matt Butcher, P.E., KC3WD, Sublight Engineering PLLC, www.sublight.net, for editing the explanation of maximum permissible exposure language for the printout of “Pwr_Dens” (the program by

Ed Parsons, BSEE, MSEE, K1TR, that calculates exposure using the OET-65 formulas – and thanks to K1TR!).

In other words, this program, and its concepts, have stood the test of time (20 years). Also, this program has text, which effectively (in my opinion) responds in greater detail than merely “pass or does not pass.” As you can see below, in his own words, K1TR grants permission to ARRL to publish his program.

K1VR comments:

· This is an executable file. It deposits the results into the folder from which it is run. I am forever forgetting which folder I ran it from, and must hunt down the results. It should be a web-based program. K1TR agrees.

· This program does allow you to specify transmitter output, feedline loss, and antenna gain, thereby avoiding the EIRP/ERP problem.

· The program allows for a person standing on the ground (and does the trigonometry), or a straight shot at a nearby 20 story apartment building.

· I like my own writing in the text print out more than I like the writing of others on the topic of calming down neighbors.

· I’m guessing that Ed would have to learn about how to construct a web page calculator. Someone else may be able to do this pretty quickly, and no additional permissions or payments are necessary to use his programming and my words. Text credits to him and to me would be sufficient.

It’s all yours, if you want it.

-Fred K1VR

From: Parsons, Ed (EXT - US/Westford) [mailto:ed.parsons.ext@nokia.com]
Sent: Sunday, April 11, 2021 2:52 PM
To: hopengarten@post.harvard.edu
Subject: pwr_dens program name change

Fred,

FYI I changed the name of the Windows app from pwr_dens_4.0_beta2.exe to pwr_dens_4.0.exe and uploaded it to https://www.qsl.net/k1tr/Downloads.htm as a zip file.

Many e-mailers (e.g. MS Outlook) won’t allow attaching an .exe file to an email but it will allow attaching a .zip file.

From: Fred Hopengarten <hopengarten@post.harvard.edu>
Sent: Monday, April 5, 2021 11:49 PM
To: Parsons, Ed (EXT - US/Westford) <ed.parsons.ext@nokia.com>
Subject: RE: [ALU] FW: [arrl-odv:32203] Effective Date for RF Safety Rule Changes

OK, Ed. Thanks.

-Fred

From: Parsons, Ed (EXT - US/Westford) [mailto:ed.parsons.ext@nokia.com]
Sent: Monday, April 05, 2021 4:39 PM
To: hopengarten@post.harvard.edu
Subject: RE: [ALU] FW: [arrl-odv:32203] Effective Date for RF Safety Rule Changes

Yes it is okay to share with the ARRL and FCC. pwr_dens.exe is a Windows app, not an on-line calculator. I see some advantages to having an on-line version:

· Nothing to download for the user. A lot less likely to get tangled in a user’s virus protection software.

· Always up-to-date. The user doesn’t need to download a new version to get the latest bug fixes or improvements.

This is something I may look into if I get some time..

From: Fred Hopengarten <hopengarten@post.harvard.edu>
Sent: Monday, April 5, 2021 2:28 PM
To: Parsons, Ed (EXT - US/Westford) <ed.parsons.ext@nokia.com>
Subject: [ALU] FW: [arrl-odv:32203] Effective Date for RF Safety Rule Changes

Ed,

Is it OK for me to recommend your program to the FCC and/or ARRL?

-Fred K1VR