Date
1  7 of 7
RF Exposure Evaluation
Jim, N5IB
Had some "nothing to do" time today so decided to spend a few quality minutes performing my "due diligence" with the ARRL's RF Exposure Caculator at
http://arrl.org/rfexposurecalculator I ran four cases, for all bands from 160m to 6m, making the most conservative of assumptions  zero feedline loss, theoretical dipole gain of 2.14 dBi, calculating with ground reflections, and rounding all distances (for the uncontrolled environment up to the nearest tenth of a foot Case 1: 100 W out, "brick on the IC706 key" that is 100% Tx, 24/7 Case 2 100 W out, normal CW , that is 40% Tx duty, 2 min Tx then 2 min Rx Case 3: 15 W out, "brick on the K2 key", that is 100% Tx, 24/7 Case 4: a Bayou Jumper doing normal Secret Agent stuff The results are shown on the attached graph. Jim, N5IB


Johnny AC0BQ
Thank Jim That’s interesting. I guess I should run one for 100 watts and another for 5, all CW. So, if I read your chart correctly, the 100% 24/7 calculation, you would need to be 12 feet or so from your dipole, is this correct? 72 Johnny ACØBQ
On Mon, Sep 13, 2021 at 3:08 PM Jim, N5IB <n5ib@...> wrote: Had some "nothing to do" time today so decided to spend a few quality minutes performing my "due diligence" with the ARRL's RF Exposure Caculator at 
Check out the 4SQRP website at 4sqrp.com


Johnny AC0BQ
Sorry, That should have been 13.5 feet.

Check out the 4SQRP website at 4sqrp.com


Jim, N5IB
Hi Johnny,
That's right  13.5 feet. Though for a situation that would never not in real life. Throw in the more realistic duty cycle, feedline loss, cloud warming antenna pattern, etc, and it's much less. But I like the worst case test, since I know my operation never even approaches that. BTW  ain't the BJ cute, hiding down there in the grass? Jim, N5IB


Johnny AC0BQ
Thanks Jim Yes the Jumper is hardly visible! You could do a lot of “secret” work with that rate of exposure. 72 Johnny
On Mon, Sep 13, 2021 at 7:27 PM Jim, N5IB <n5ib@...> wrote: Hi Johnny, 
Check out the 4SQRP website at 4sqrp.com


davemrtn
You must have been really bored and needing something to do ! !
David Martin  NA1MH  Mountain
Home, Ar.
 Wherever I go, there He is.
On 9/13/2021 2:15 PM, Jim, N5IB wrote:
Had some "nothing to do" time today so decided to spend a few quality minutes performing my "due diligence" with the ARRL's RF Exposure Caculator at http://arrl.org/rfexposurecalculator I ran four cases, for all bands from 160m to 6m, making the most conservative of assumptions  zero feedline loss, theoretical dipole gain of 2.14 dBi, calculating with ground reflections, and rounding all distances (for the uncontrolled environment up to the nearest tenth of a foot Case 1: 100 W out, "brick on the IC706 key" that is 100% Tx, 24/7 Case 2 100 W out, normal CW , that is 40% Tx duty, 2 min Tx then 2 min Rx Case 3: 15 W out, "brick on the K2 key", that is 100% Tx, 24/7 Case 4: a Bayou Jumper during normal Secret Agent ops The results are shown on the attached graph. Jim, N5IB


Curt
Jim,
Thanks for the fine work! You ought to publish this in QST, with a little subtle advertising about the Jumper and why every ham needs one. I have been doing my part, managed to sell two ops on how much fun the Jumper is, and what great fun it is to build and operate. Curt, KB5JO

