This is a link to an article investigating leukemia rates in areas near AM
transmitters.

http://www.wired.com/news/medtech/0,1286,64579,00.html

I don't doubt that high levels of RF can be dangerous. The first two chief
engineers I worked with both died of cancer in their 50s.

Maybe they got cancer from some other cause (both smoked), but I still feel
like I'm inside a microwave oven anytime I'm around an AM transmitter site.

"lsmyer" wrote in message
...
This is a link to an article investigating leukemia rates in areas near AM
transmitters.

http://www.wired.com/news/medtech/0,1286,64579,00.html

I don't doubt that high levels of RF can be dangerous. The first two chief
engineers I worked with both died of cancer in their 50s.

Maybe they got cancer from some other cause (both smoked), but I still
feel
like I'm inside a microwave oven anytime I'm around an AM transmitter
site.




Wouldn't FM broadcast antennas be an even greater concern? The height of
most adults would make them resonant somewhere near, or in, the FM broadcast
band. I'd expect energy transfer to be more effiecnt from the FM broadcast
antenna to the human body than it is in the AM broadcast band.

Anyway, there's been over 80 years of kW+ levels of AM broadcasting, and it
seems strange this leukemia concern has gone unnoticed until now.

Frank Dresser

"Frank Dresser" wrote in message
...

Anyway, there's been over 80 years of kW+ levels of AM broadcasting, and
it
seems strange this leukemia concern has gone unnoticed until now.

Hi Frank,

Good point but compare to asbestos causing cancer where it can take 60 years
to appear.

I also often wonder what PCs are doing to us all staring at them all day,
we may be in for a big health shock in the years to come!

Also mobiles may ruin the brain. The consequences could be disastrous.

Happy thoughts!!

Cheers

Mike

"Mike Terry" wrote in message
...

"Frank Dresser" wrote in message
...

Anyway, there's been over 80 years of kW+ levels of AM broadcasting, and
it
seems strange this leukemia concern has gone unnoticed until now.

Hi Frank,

Good point but compare to asbestos causing cancer where it can take 60
years
to appear.

Yes, but researchers can also sift through 80 years of public health
records. The people who have, or had, leukemia are known. It shouldn't be
hard to find out who lived near a radio transmitter and for how long. It
might be interesting to ask veterinarians about animal leukemia, since many
transmitters are located in rural areas.

But, since this story is being treated as news, I don't think there are even
any "rural legends" about a connection between leukemia and AM radio
transmitters.

Let's not forget that perfectly random chance is going to usually give us
lumpy results. A perfectly smooth map of leukemia cases would be something
like flipping a quarter ten times and getting exactly a h-t-h-t-h-t-h-t-h-t
result. It could happen, but any lumpy combination is just as likely, and
there are more lumpy combinations to go around.

Random chance alone might give us some leukemia hot spots. Some of those
hot spots might be near AM transmitters. It'll be interesting to see if
other leukemia hot spots are around AM radio transmitters, or if is just one
of those weird number things.


I also often wonder what PCs are doing to us all staring at them all day,
we may be in for a big health shock in the years to come!


Brother Stair used to say that the Internet was Satan's entryway into the
home. He seems to have softened his opposition lately. His website has a
page accepting donations using credit cards and paypal.



Also mobiles may ruin the brain. The consequences could be disastrous.

Mobiles as cellphones? Yes, there's no need to do studies to observe the
brain damage caused by those evil things. Just observe the cellphone addled
drivers as they careen from one close call to the next. The damage is
self-evident. Well, I don't need no stinkin' cellphone to damage my brain.

I'll stick with shortwave radio.


Happy thoughts!!

Cheers

Mike



Frank Dresser

Yes, but researchers can also sift through 80 years of public health
records. The people who have, or had, leukemia are known. It shouldn't be
hard to find out who lived near a radio transmitter and for how long. It
might be interesting to ask veterinarians about animal leukemia, since many
transmitters are located in rural areas.

Do you really need to have people smoke cigarettes for 80 years before you agree
that inhaling smoke into your lungs is going to cause health problems?

These are all basic things we should know without having to go through decades
of health records to figure out.

I knew in 1983 that Aspartame was a horror, yet only now are people starting to
figure that out.

Let's not forget that perfectly random chance is going to usually give us
lumpy results. A perfectly smooth map of leukemia cases would be something
like flipping a quarter ten times and getting exactly a h-t-h-t-h-t-h-t-h-t
result. It could happen, but any lumpy combination is just as likely, and
there are more lumpy combinations to go around.

Same with trying to link lung problems with smoking. But can you seriously
say that breathing smoke into your lungs is not going to cause health
problems? Just use common sense.

Random chance alone might give us some leukemia hot spots. Some of those
hot spots might be near AM transmitters. It'll be interesting to see if
other leukemia hot spots are around AM radio transmitters, or if is just one
of those weird number things.

While you do all that, I will just avoid living next to any AM or FM radio
transmitters. I wish I could do the same with Microwave Cellular towers, but
that is getting impossible to avoid today.

I also often wonder what PCs are doing to us all staring at them all day,

LCD screens are obviously much safer and healthier than the CRT screens. Do
we really need studies on that too, or can we all use common sense to figure
that one out as well?

Brother Stair used to say that the Internet was Satan's entryway into the
home.

Satan is make-believe.

Also mobiles may ruin the brain. The consequences could be disastrous.

May?!

Mobiles as cellphones? Yes, there's no need to do studies to observe the
brain damage caused by those evil things.

Exactly.

Go to http://tx.mb21.co.uk/gallery/ and look at some of their AM/MW
sites. Not only do many of them still use those cool T-shaped
horizontal wire antennas, but in some shots you can see sheep grazing in
the fields very close by. The RF foes in the USA should consult with
veterinarians in the UK and see what their research comes up with

GTT




Truth wrote:
Yes, but researchers can also sift through 80 years of public health
records. The people who have, or had, leukemia are known. It shouldn't be
hard to find out who lived near a radio transmitter and for how long. It
might be interesting to ask veterinarians about animal leukemia, since many
transmitters are located in rural areas.

(snip)

Frank Dresser wrote:
Wouldn't FM broadcast antennas be an even greater concern? The height of
most adults would make them resonant somewhere near, or in, the FM broadcast
band. I'd expect energy transfer to be more effiecnt from the FM broadcast
antenna to the human body than it is in the AM broadcast band.

I'd sure think so.

On the other hand, the FM signal is radiated from an antenna atop the
tower. Stand at the base of a 300' FM tower, and you're 300' from the
thing that radiates.

At an AM station, the entire tower radiates.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

"Doug Smith W9WI" wrote
On the other hand, the FM signal is radiated from an antenna atop the
tower. Stand at the base of a 300' FM tower, and you're 300' from the
thing that radiates.

At an AM station, the entire tower radiates.
___________

Also - most FM broadcast transmit antennas are arrays of several elements in
a vertical stack to concentrate radiation in the horizontal plane. As a
result the radiation directed around the tower base is much lower than the
station's licensed power.

RF

Visit http://rfry.org for FM broadcast RF system papers.

"Doug Smith W9WI" wrote in message
...
Frank Dresser wrote:
Wouldn't FM broadcast antennas be an even greater concern? The height of
most adults would make them resonant somewhere near, or in, the FM broadcast
band. I'd expect energy transfer to be more effiecnt from the FM broadcast
antenna to the human body than it is in the AM broadcast band.

I'd sure think so.

On the other hand, the FM signal is radiated from an antenna atop the
tower. Stand at the base of a 300' FM tower, and you're 300' from the
thing that radiates.

At an AM station, the entire tower radiates.

One of the issues with most FM arrays with gain is that, for many, the spacing which
results in the array having gain also results in a fairly pronounced hot-spot
directly above the antenna, where few people would be expected to be, as well as
directly below, where technical personnel might spend a substantial amount of time.
Personally, I think that the AM radiation hazards are overstated in this study, and
that the issue comes more from environmental circumstances by virtue of the fact that
many AM transmitter installations share the same area as other industrial concerns.
--
-----------------------------------------------------------------------------
If there's nothing that offends you in your community, then you know you're not
living in a free society.
Kim Campbell - ex-Canadian Prime Minister - 2004
-----------------------------------------------------------------------------
For direct replies, take out the contents between the hyphens. -Really!-

"Bob Haberkost" wrote
One of the issues with most FM arrays with gain is that, for many,
the spacing which results in the array having gain also results
in a fairly pronounced hot-spot directly above the antenna,
where few people would be expected to be, as well as
directly below...
_________________

This is true only when each element in the array has high relative field at
+/-90 degree elevation, and the elements are vertically spaced about one
wavelength apart. Shorter vertical spacings reduce such radiation from
these arrays. Using 1/2 wave spacing reduces it to a theoretical zero at
+/-90 degrees elevation (the zenith and nadir).

BUT, the great majority of FM broadcast transmit elements used today have
elevation patterns with very low relative field at +/90 degrees. An array
of such elements also has low relative field at +/-90 degrees -- even with
elements spaced at one wavelength intervals. IOW, no hot-spots above and
below the array.

Patterns of four element types in common use today, and an elevation pattern
for a 6-element, 1-wave-spaced array of one type are included in the PDF
slide show listed as Paper 10 at http://rfry.org.

RF