Pages: [1] 2   Go Down

Author Topic: Updated Radio Frequency Exposure Rules Become Effective on May 3:  (Read 519 times)

N2RRA

  • Member
  • Posts: 863
    • homeURL

This subject was posted on the eham news post. I read their post then starting reading the FCC’s 179 page PDF, but brain scrambled and went to sleep by the 10th page.

So what evaluation are they talking about and how is that gonna happen?

Are you expected to have them come to your house to make their evaluation and be subjected to scrutiny at the level to discourage you from having a ham station so they can limit how many people are running off grid communications?

I know it sounds like conspiracy analyzing, but the way things are going I wouldn’t doubt it.

Can someone who read all 179 pages, or someone who actually knows the process clarify what’s actually going to take place in this whole news rules update?

Thanks
Logged

W4MDP

  • Posts: 42
    • HomeURL
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #1 on: April 15, 2021, 08:16:43 PM »

Its not a conspiracy against you by the government.  The new rules were published in December if 2019 and somw forms of them have been on the books since 1969(The National Environmental Policy Act of 1969)

THE SHORT ANSWER-----Actually the RF Exposure rules have not really changed.  They have revised them methods of testing by defining various types of products and expanded the justifications of what the rules are based on.  I am a communications consultant and one of my specialties is RF exposure.  I'll be teaching a class on it at the IWCE show in September. (It was supposed to be at the 2020 show in April 2020)   An actual example--Without these rules Baofeng was going to release an 18 watt handheld last year to melt your eyeballs

73
Mark
Logged

N2RRA

  • Member
  • Posts: 863
    • homeURL
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #2 on: April 15, 2021, 10:55:14 PM »

Its not a conspiracy against you by the government.  The new rules were published in December if 2019 and somw forms of them have been on the books since 1969(The National Environmental Policy Act of 1969)

THE SHORT ANSWER-----Actually the RF Exposure rules have not really changed.  They have revised them methods of testing by defining various types of products and expanded the justifications of what the rules are based on.  I am a communications consultant and one of my specialties is RF exposure.  I'll be teaching a class on it at the IWCE show in September. (It was supposed to be at the 2020 show in April 2020)   An actual example--Without these rules Baofeng was going to release an 18 watt handheld last year to melt your eyeballs

73
Mark

LOL, well everyone just LOVES those Chinese products at any cost so....🤷🏼‍♂️

So what do they mean then by “evaluation”? Who’s going to evaluate and confirm weather, or not you can proceed to keep your station running, or did I misunderstand and misinterpret what they meant by that?
Logged

W4MDP

  • Posts: 42
    • HomeURL
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #3 on: April 15, 2021, 11:44:01 PM »

Again--a short version --Evaluating means doing the math to determine the RF levels where people are.  The League has a nice RF exposure "do it yourself" document that can be found on line. 
Here are some downloadable docs pretty much in plain language

OET Bulletin 56 - Questions and Answers about Biological Effects and Potential Hazards of Radiofrequency Electromagnetic Fields

OET Bulletin 65 - Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields

A Local Government Official’s Guide to Transmitting Antenna RF Emission Safety:  Rules, Procedures, and Practical Guidance

Electromagnetic Energy – Evaluation and Management for Antenna Sites (Motorola)

The FCC docs are at:http://www.fcc.gov/oet/rfsafety

OET 65 has the do it yourself tables and calculations.  The Local government's guide is written for, shall we say, "non-technical" persons.
Logged

G8FXC

  • Member
  • Posts: 533
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #4 on: April 16, 2021, 12:28:55 AM »

If you are running moderate power levels into simple antennae, then the isolation distance from your antennae will be a few feet - as in six to ten feet. Running a kW into a 5 element beam pointing into your neighbour's bedroom a few feet away is probably going to break the rules! There are on-line calculators available. I assume that the FCC rules are going to be similar to those introduced by OFCOM in Britain - you are required to carry out the assessment using one of the available modelling tools and keep a record of the result to prove you've done it. Provided the numbers that come out indicate that you have a fair safety margin, then that's it - you only need to carry out more detailed modelling or real-world measurement if the tools indicate that you are probably not compliant.

The tool promoted by OFCOM/RSGB is a simple spreadsheet - you key in the frequency of operation, power level and operating mode plus the details of your feeder (type and length) and select from a list of antenna types and it calculates the required isolation distance between the antenna and any area that the public can access. It tells me that for my 100W into a dipole with my grotty feeder, the isolation distance is less than six feet...

Martin (G8FXC)
Logged

W1VT

  • Member
  • Posts: 6071
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #5 on: April 16, 2021, 09:45:34 AM »

I calculated 42% as the maximum duty cycle for FT8 under normal worse case conditions.
This number is missing from OET bulletin 65 as nobody had any idea that this new mode would be invented back then.

The absolute worst case duty cycle for digital is 100%, if a Windows update causes you transmitter to lock up and transmit at full output.

Extreme low power enthusiasts may be able to take advantage of the 1 mW categorical exemption from 100 kHz to 100GHz.

Zak W1VT
« Last Edit: April 16, 2021, 09:49:26 AM by W1VT »
Logged

N9FB

  • Member
  • Posts: 2702
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #6 on: April 18, 2021, 06:46:51 AM »

If you are running moderate power levels into simple antennae, then the isolation distance from your antennae will be a few feet - as in six to ten feet. Running a kW into a 5 element beam pointing into your neighbour's bedroom a few feet away is probably going to break the rules! There are on-line calculators available. I assume that the FCC rules are going to be similar to those introduced by OFCOM in Britain - you are required to carry out the assessment using one of the available modelling tools and keep a record of the result to prove you've done it. Provided the numbers that come out indicate that you have a fair safety margin, then that's it - you only need to carry out more detailed modelling or real-world measurement if the tools indicate that you are probably not compliant.

The tool promoted by OFCOM/RSGB is a simple spreadsheet - you key in the frequency of operation, power level and operating mode plus the details of your feeder (type and length) and select from a list of antenna types and it calculates the required isolation distance between the antenna and any area that the public can access. It tells me that for my 100W into a dipole with my grotty feeder, the isolation distance is less than six feet...

grotty feeder? this seems like a pretty simple evaluation of the station a licensee is responsible for, but i can't help asking -- isn't their an app for that? (simply plug in wattage, freq, etc. and read out safe distance?)

Quote
UPDATED RF EXPOSURE RULES ARE EFFECTIVE MAY 3
The new rules do not change existing RF exposure (RFE) limits but do require that
stations in all services, including amateur radio, be evaluated against existing limits,
unless they are exempted. For stations already in place, that evaluation must be
completed by May 3, 2023. After May 3 of this year, any new station, or any existing
station modified in a way that’s likely to change its RFE profile — such as different
antenna or placement or greater power — will need to conduct an evaluation by the date
of activation or change.

“For most amateurs, the major difference is the removal of the categorical exclusion for
amateur radio, which means that ham station owners must determine if they either qualify
for an exemption or must perform a routine environmental evaluation,” said Greg Lapin,
N9GL, chair of the ARRL RF Safety Committee and a member of the FCC
Technological Advisory Council (TAC).
For more information, go to
http://www.arrl.org/news/updated-radio-frequency-exposure-rules-become-effective-on-may-3
« Last Edit: April 18, 2021, 06:52:37 AM by N9FB »
Logged
"When you throw dirt, you lose ground."

N9FB

  • Member
  • Posts: 2702
Logged
"When you throw dirt, you lose ground."

W1VT

  • Member
  • Posts: 6071
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #8 on: April 25, 2021, 10:57:36 AM »

"The Amateur Service is no longer categorically excluded from certain aspects of the rules, as amended, and licensees can no longer avoid performing an exposure assessment simply because they are transmitting below a given power level."

This means that Table 1.1 shown above is now obsolete.  The FCC provides a formula using ERP to calculate the new exemptions, but in practice, it is easier to perform the assessment with an online calculator than to calculate whether you qualify for an exemption.
Logged

AA4PB

  • Member
  • Posts: 15504
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #9 on: April 25, 2021, 01:34:12 PM »

"isn't their an app for that? (simply plug in wattage, freq, etc. and read out safe distance?)"

Yes, there are several available for free on the Internet. Some are "on-line" calculators and some are programs that you can download and install on your computer. One downloadable is called "RF Safety Calculator".
Logged
Bob  AA4PB
Garrisonville, VA

N9FB

  • Member
  • Posts: 2702
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #10 on: April 28, 2021, 09:57:47 AM »

Quote
"isn't their an app for that? (simply plug in wattage, freq, etc. and read out safe distance?)"

Yes, there are several available for free on the Internet. Some are "on-line" calculators and some are programs that you can download and install on your computer. One downloadable is called "RF Safety Calculator".

that was easy, thanks  :) => http://hintlink.com/power_density.php
Logged
"When you throw dirt, you lose ground."

W9IQ

  • Member
  • Posts: 8866
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #11 on: April 28, 2021, 10:02:57 AM »

Quote
"isn't their an app for that? (simply plug in wattage, freq, etc. and read out safe distance?)"

Yes, there are several available for free on the Internet. Some are "on-line" calculators and some are programs that you can download and install on your computer. One downloadable is called "RF Safety Calculator".

that was easy, thanks  :) => http://hintlink.com/power_density.php

Unfortunately, that site has at least one serious error which brings its results into question. It says to enter a gain of 2.2 dB for a dipole. That would only be true if the dipole was in free space. Most back yard dipoles will have > 6 dBi of gain or put another way, more than 4 dBd of gain.

- Glenn W9IQ
Logged
- Glenn W9IQ

God runs electromagnetics on Monday, Wednesday and Friday by the wave theory and the devil runs it on Tuesday, Thursday and Saturday by the Quantum theory.

W9IQ

  • Member
  • Posts: 8866
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #12 on: April 28, 2021, 10:36:56 AM »

Another serious error at that site is the input label "The ERP at the antenna". Based on context, this should read "Power applied to the antenna feedpoint".

I would avoid relying on any results from that site.

- Glenn W9IQ
« Last Edit: April 28, 2021, 10:40:23 AM by W9IQ »
Logged
- Glenn W9IQ

God runs electromagnetics on Monday, Wednesday and Friday by the wave theory and the devil runs it on Tuesday, Thursday and Saturday by the Quantum theory.

K6AER

  • Member
  • Posts: 7159
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #13 on: April 29, 2021, 03:45:50 PM »

Do the new rules take into effect the antenna beam pattern? A 100 watt signal from a ground mounted will have a much higher RF level than a KW a 100 feet going out into space where no one is.
Logged

K7NI

  • Member
  • Posts: 84
Re: Updated Radio Frequency Exposure Rules Become Effective on May 3:
« Reply #14 on: April 29, 2021, 07:15:10 PM »

Antenna gain is part of the equation and it should be the maximum gain in a direction there might be people.
Logged
Pages: [1] 2   Go Up