[BC] uplink ERP - RF hazard?

[Broadcast List]

OK, to address some of this stuff...

Keep in mind that the limits are several hundred times less than  
where anyone THINKS there is an issue -- and the only issue from non- 
ionizing radiation is heating, nothing more.

There are only really TWO issues for heating, one important and one  
-- not so much.

The first is the eyes.  Because the eyes are filled with fluid, and  
there is no blood flow to remove the heat, heating the eyes is a real  
concern.  I know someone who looked into the PA of a C-Band dish and  
really hurt himself.  He has no night vision, and his vision is very  
much damaged.  His eyes were heated, and damaged.  Don't do that!

The other is the testicles.  They hang to keep cooler than the  
nominal 98.6 Degrees Fahrenheit (great song, 98.6 by Keith) of the  
rest of our (male) bodies in order to produce sperm.  If they are  
heated, they stop producing sperm.  HOWEVER, once they cool, they  
begin again.  No harm, no problem, and for me, GOOD NEWS.  Sterile --  
no problem.  Impotent -- PROBLEM!  So, heating is no problem.

Like Cowboy, I wouldn't have a problem walking in front of it, but I  
don't think I would want to look at it for an extended period.

Keep this in mind, the woman in charge of the original testing at EPA  
used to arrive at the lab in the morning, walk to the diathermy  
chamber, open the door (to open the interlocks), turn on 10 kW of RF,  
enter the chamber and close the door.  This closed the interlocks and  
turned on the RF.  Once she warmed up, she would open the door  
(opening the interlocks), turn off the transmitter, and remove her  
hat, scarf and coat.  She would begin her day.


Regarding AM fields, GET REAL!  You really cannot exceed safe levels  
without touching the steel.  Yes, there are arguments, and now people  
are stating you can (once again) climb an energized tower.  I'm  
unwilling to allow this, but I do understand it.  (I fear future law  
suits.)  You cannot overheat your eyes on an AM tower, so who cares?   
If you live off the ground system, your only concerns are your  
wireline phone and stereo.  Get over it, and construct some loops so  
you don't have to pay for lighting!

Finally, there are several studies, including a very large British  
study that shows heating the brain somewhat aids in the ability to  
"work" or compute, and especially to learn.  They were mostly  
concerned about their 900 MHz and 1800 MHz phones, but as they were  
trying to show it was bad, they showed the minor heating was actually  
good.


Bottom line:  Don't look into any high power feed horn.  THAT can be  
bad for your eyes.  Also, if you are actively trying to become a  
daddy, don't heat your nuts.  On American Airlines (First Class) warm  
nuts are good, but if you are trying to be a daddy.... not so much.   
On the other hand, if your woman and you are at odds on the subject...


Hey, understand this:  Lay on the beach at Noon with no sun-block.   
What happens?  You get sunburn.

Go out at night, at a full moon.  Lie out there.  Any problem?  Of  
course not.  It is a matter of exposure.  (Ignoring the sun's  
ionizing radiation) sun light doesn't hurt you, as long as the  
exposure is reasonable.  Overheat?  Problem.  Sunburn.  Just like RF,  
sunlight can be bad if you get too much, but as long as you don't  
have heating effects, it isn't a problem.  PLUS, a little heating is  
fine, as long as the blood can take away the heat.


This RF fear really makes me angry.  Read the studies.  Get over it.   
Unless it is ionizing, it isn't bad.


On Jan 13, 2008, at 6:00 AM, broadcast-request at radiolists.net wrote:

> Message: 24
> Date: Sat, 12 Jan 2008 22:51:12 -0500
> From: "Paul B. Walker, Jr." <walkerbroadcasting at gmail.com>
> Subject: Re: [BC] uplink ERP - RF hazard?
> To: "Broadcasters' Mailing List" <broadcast at radiolists.net>
> Message-ID:
> 	<8bce0fe80801121951u24549b50i6939c4403eb68ce8 at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> It's a good thing I dont ever plan on having kids...
>
> I've lived within just several hundred feet of...
>
> a 250 Watt Daytimer on 1520
> a 5KW Day/1KW Night Fulltimer on 1300
> a 1 KW Fulltimer on 1340
> a 1KW Daytimer on 1590
>
> Paul
>
> On Jan 12, 2008 10:38 PM, Cowboy <curt at spam-o-matic.net> wrote:
>
>>
>> <<snip>>
>>  Of course, blindness and sterility just like any radar  
>> transmitting array
>>  if you stay there long enough directly in the boresight.
>>
>>  I'd walk across it without a second thought, but I wouldn't stand  
>> there
>> three
>>  feet in front of it for hours on end.
>>
>> --
>> Cowboy




On Jan 13, 2008, at 6:00 AM, broadcast-request at radiolists.net wrote:
> Message: 21
> Date: Sat, 12 Jan 2008 20:29:41 -0700
> From: "John Lyles" <jtml at losalamos.com>
> Subject: [BC] uplink ERP - RF hazard?
> To: broadcast at radiolists.net
> Message-ID: <9b4e5917e20b6d9566c1cebaf58a0c82 at losalamos.com>
> Content-Type: text/plain; charset="us-ascii"
>
> I've finally given up on a pair of copper wires nailed to a tree,  
> were 26 Kbps had been all I could get for service out here in the  
> sticks from Qwest - for the past 15 years. I bought a Ka band setup  
> via Wildblue, which uses a 0.6m Raven Corvus Range dish. This  
> provides sub-DSL speeds, and there are limits to the amount of  
> gigabytes I can download per month. Not a problem for us out here,  
> as even 10 - 20 x over our modem will seem like science fiction to us.
>
> Question is:
> The dish has 44.4 dBi gain at the transmit frequency, 29.75 GHz.  
> One can imagine the pencil beam out of this thing at Ka band. I am  
> going to guess that the transmitter is 1 watt or less, based on the  
> price of the setup ($250 for the antenna, T/R and modem). There is  
> no feedline loss as only downconverted freq is shipped down to the  
> modem.  With this gain, I figure I have about a 20 kW ERP out in  
> front of this thing. Am I doing something wrong calculating this?  
> Does anyone know the actual value for this satellite internet system?
>
> Is this level at 29.75 a hazard? I can check the IEEE/ANSI standard  
> myself, but just wanted a general collective opinion. Since this is  
> a home environment, I would have to set my own safety standards  
> such as turning off the modem when working on the roof (it is flat  
> and the dish is being placed there Thursday). I have VHF,  
> television, amateur, UHF, yagis, you name it, already up there.
>
> Regards,
> John