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/rf-exposure-calculator

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 IC-706 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
http://arrl.org/rf-exposure-calculator

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 IC-706 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






--
Check out the 4SQRP website at 4sqrp.com


Johnny AC0BQ
 


Sorry,
That should have been 13.5 feet.

On Mon, Sep 13, 2021 at 5:47 PM Johnny AC0BQ via groups.io <jomatlock=gmail.com@groups.io> wrote:
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
http://arrl.org/rf-exposure-calculator

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 IC-706 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






--
Check out the 4SQRP website at 4sqrp.com

--
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,

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






--
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/rf-exposure-calculator

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 IC-706 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