[bars] RF Exposure Calculator

[apizer at comcast.net]

Bruce,

Thanks.  This makes it easy for those who don't have time for additional
projects right now.  Thanks to your link I now know I am all set on any
frequencies and power levels I would operate.

Art

NF1A

 

 

From: bars <bars-bounces at w1hh.org> On Behalf Of Bruce Anderson
Sent: Friday, August 6, 2021 1:18 AM
To: bars at w1hh.org
Subject: [bars] RF Exposure Calculator

 

We are all required to calculate the RF exposure to people from our
transmissions.

The results should show that our antennas are located far enough from people
so no one gets over exposed. 

Or inversely where to locate our antennas to prevent over exposing people to
our transmissions.

The ARRL has provided a simple calculator for hams to determine this minimum
safe distance.

 

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


 <http://arrl.org/rf-exposure-calculator> RF Exposure Calculator

The FCC has adopted guidelines and procedures for evaluating environmental
effects of RF emissions. The new guidelines incorporate two tiers of
exposure limits based on whether exposure occurs in an occupational or
"controlled" situation or whether the general population is exposed or
exposure is in an "uncontrolled" situation.

arrl.org

 

Below in a sample calculation I did for my FT 8 transmissions on 20 Meters
running 100 watts to a half wave dipole.

 

The results show two feet away for myself and family is safe and 4.5 feet
away is safe for Neighbors.

Of course, since the antenna is over 15 feet high there is no issue with
this antenna and power on 20 Meters. 

 

RF Exposure Calculator 

Parameters

Power at Antenna: 100 (watts)

Mode duty cycle: AFSK SSB (duty cycle=100%)  (FT 8)

Transmit duty cycle: (time transmitting)

You transmit for 1 minutes then receive for 1 minutes (and repeat).

Antenna Gain (dBi): 2.15 (1/2 wave Dipole)

Operating Frequency (MHz): 14.074

Include Effects of Ground Reflections

 

Results for a controlled environment:

Maximum Allowed Power Density (mw/cm2): 4.5437

Minimum Safe Distance (feet): 1.9897

Minimum Safe Distance (meters): 0.6065

 

For an uncontrolled environment:

Maximum Allowed Power Density (mw/cm2): 0.9087

Minimum Safe Distance (feet): 4.4490

Minimum Safe Distance (meters): 1.3561

 

Bruce

W1LUS

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.w1hh.org/pipermail/bars_w1hh.org/attachments/20210806/844887e8/attachment.htm>