Radio Frequency (RF) & Wireless Design

There is a recent article in the ARRL QEX magazine titled "Amateur Portable Radios (Handheld Transceivers) - Exposure Considerations Based on SAR" which addresses the exposure levels of Radio Frequency (RF) radiation and the risks as Specific Absorption Rate (SAR) for the human body as a model (HBM).

http://www.arrl.org/files/file/QEX_Next_Issue/2021/07%20Jul-August%202021/07%20JulAug21%20QEX%20Tell.pdf

This article is important since almost all old and new Amateur Radio operators worldwide start out on the VHF and UHF bands as part of the initial Technician licensee. In addition the first and primary radio that almost everyone starts out with are the low cost handheld transceivers.

The issue is that these transceivers can output as much as 5 Watts and people should understand the risks of using these devices in a high power mode. Moreover, they need to understand the risks in even 'normal' 1 Watt power modes as well.

Although most Amateur Radio operators are taught to use the lowest power necessary to achieve reliable and clear communications, it is too tempting to push the power to the maximum to always have the best RF link available, especially when operating at the fringe of the repeater range.

It is advisable to use handhelds for the briefest of communications (as in seconds) rather than minutes, especially when using the transceiver close to you head when transmitting.

I have been told that when I talk into my Yaesu VX-7R handheld, that I should press the microphone against my cheek and talk across the microphone for the best audio quality. However, there was never any discussion on how far I need to keep the antenna away from my head and especially away from my eyes !!

From reading this article, I encourage anyone that uses a handheld RF transceiver, to re-evaluate getting a corded microphone and use it instead of the handheld microphone like this one : https://www.dxengineering.com/parts/ysu-ssm-63a?seid=dxese1

or this one : https://www.gigaparts.com/heil-handi-talkie-headset-yaesu.html

such that you can hold the handheld away from you body and the microphone close to your cheek.

In the most recent press from the FCC to the ARRL, the FCC is making radio operators aware of the SAR dangers and the need to take greater safety measures to protect your body and especially your eyes from RF radiation.

http://www.arrl.org/news/updated-radio-frequency-exposure-rules-become-effective-on-may-3

The ARRL is aware of this and is also promoting the information to get everyone aware of the situation, and especially to older hams :

http://www.arrl.org/rf-exposure

Buying a corded microphone or headset (and possibly with VOX) is a very low cost solution to get the handheld RF emissions away from your head, eyes, and body to ensure the safest operation especially when engaging in long QSOs.

The next best measure is to unscrew the antenna and place a coax attached antenna that will move the antenna even further away from your body. In this case you will also get much better gain from the antenna and longer range without having the need to push for higher output power as well.

Take care and 73 !