[Elecraft] RF Exposure Levels

[Dauer, Edward]

Thanks, Bob.  I received a couple of other private replies raising the 
same question, about RF exposure using an amp and an indoor antenna.  
There is an RF exposure calculator available on the ARRL’s site, or 
directly at http://hintlink.com/power_density.htm.  My configuration at 
100 watts is only about 1/4 of the safe maximum.  Nonetheless your caution 
is appreciated and well advised - hence my posting the calculator site 
here for any others who might be sitting close to their antennas.

Ted, KN1CBR


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Message: 21
Date: Sat, 30 Jan 2016 18:48:29 -0600
From: Bob McGraw K4TAX <rmcgraw at blomand.net>
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] KXAT100 "Hunting"
Message-ID: <56AD59DD.3070600 at blomand.net>
Content-Type: text/plain; charset=utf-8; format=flowed


Candidly, I would be more concerned about exceeding the RF Exposure 
limits with this arrangement.  Perhaps the "Tuner issue" is an 
indication of such.  From your description, at 100 watts you will likely 
be way outside of the FCC limits of safe RF Exposure.

Now with that said, the amount of RF at the TUNE level is not such to 
confuse the tuner.  However at 40+ watts the RF back into the system is 
more than the system can accurately handle.  A bunch of #31 beads or #73 
beads, where "bunch" = 50 pcs or more, on the feed line at the antenna 
feed point and again a bunch at the radio. This may help the radio and 
antenna problem associated with the auto tune routine.  You may find the 
same treatment required on the DC power cable at the radio.

73
Bob, K4TAX



>------------------------------
>
>Message: 21
>Date: Sat, 30 Jan 2016 18:48:29 -0600
>From: Bob McGraw K4TAX <rmcgraw at blomand.net>
>To: elecraft at mailman.qth.net
>Subject: Re: [Elecraft] KXAT100 "Hunting"
>Message-ID: <56AD59DD.3070600 at blomand.net>
>Content-Type: text/plain; charset=utf-8; format=flowed
>
>
>Candidly, I would be more concerned about exceeding the RF Exposure 
>limits with this arrangement.  Perhaps the "Tuner issue" is an 
>indication of such.  From your description, at 100 watts you will likely 
>be way outside of the FCC limits of safe RF Exposure.
>
>Now with that said, the amount of RF at the TUNE level is not such to 
>confuse the tuner.  However at 40+ watts the RF back into the system is 
>more than the system can accurately handle.  A bunch of #31 beads or #73 
>beads, where "bunch" = 50 pcs or more, on the feed line at the antenna 
>feed point and again a bunch at the radio. This may help the radio and 
>antenna problem associated with the auto tune routine.  You may find the 
>same treatment required on the DC power cable at the radio.
>
>73
>Bob, K4TAX