"Yuri Blanarovich" wrote in message
...

Thierry wrote:
We know that during the emission of a radiotelescope (rare, for tests
or to send SETI msg, Hi!), the radiation can sterilize people working
in the dish.

Nonsense - we know nothing of the sort.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)

No-nonsense, it is sense. RF exposure causes temporary sterility, kinda
birth
control. Too much RF can cook us.

Yuri, K3BU.us


First, let's agree on nomenclature; a radio telescope is a receiving device
only, it is not an emitter. Feel free to coin a new term for a highly
directional, high power emitter used for astronomical research.

RF exposure can cause many things, from nothing sensible to boiling to
carbonization to vaporization. It all depends on the RF power, the
absorption and the time of exposure. Absorption is dependent on frequency
and conductivity of the sample. Heating is dependent on the power, the
absorption and the ability to transfer heat from the sample.

For instance, 14 GHz exposure will result in most radiation reflecting off a
human body; move the exposure to 2.4 GHz, and the effective depth of heating
will be several inches into the tissues. Move down to 960 MHz, and you will
get even deeper heating. (Consider why industrial microwave ovens are at 960
MHz.)

Some body tissues are more exposed to RF, and, having only modest blood
circulation, have a poor ability to transfer heat. Assuming you are male,
those tissues at risk would include your earlobes, fingertips, nose,
corneas, elbows, penis, scrotum, testicles and toes. Your earlobes, nose,
fingers and scrotum have good circulation, so the blood cooling helps to
protect them. Your toes are usually electrically close to the ground, and in
a region of lower power density. Your penis is also well cooled and poorly
exposed, unless RF exposure gives you a woodie. And who cares what happens
to your elbows? So that leaves your corneas and testicles as the most
vulnerable tissues.

Canadian Safety Code 6 is a well-written document that will also teach you a
lot about RF emissions, RF measurement and biological effects. It's limits
are based on old ANSI C95.3-1991 work, which has been codified as IEEE STD
C95.1-1999. The USA FCC also uses the IEEE standard. Both the IEEE and ANSI
want to charge you for access, but Industry Canada courteously provides a
free download at:

http://www.hc-sc.gc.ca/hecs-sesc/ccrpb/pdf/99ehd237.pdf

Thanks, Canada!

So we see that RF can do essentially nothing, it can sterilize, it can cook,
it can kill, and it can destroy. It's all a matter of power, frequency,
target and time.

Ed
wb6wsn