Microwave Towers In Los Killing Astro And Other Foreign Feeds

[happyjune]

This is a 2 part question, I have been told that those very large towers that host mobile phone antennas and many times dishes pointed horizontally are micro wave beams. What are thee microwave beams used for? They are everywhere.

I was told that many of these use frequency that will kill a unprotected sat feed if you are in the path of a microwave beam. eg. Thai sat frequencies are protected in Thailand, but the Astro frequency is not and these can play havoc with you.. What about Australia Network?

Is there any way to tell?

I am looking at living near one of these towers, anyone know of nasty side effects?

[jybkk]

Microwaves are electromagnetic waves with frequencies between 300MHz and 300GHz.

These frequencies have many uses. Among them:

• WiFi (typically 2.4GHz)
• GSM/3G (many different bands, typicals are 900MHz, 1800MHz, 2.1GHz). These are what those dishes are for: mobile phone network.
• GPS (1.2 to 1.6GHz)
• Radars
• Satellite Communication (4 to 40GHz)
• ...

Of courses there's also Microwave ovens, which use 2.45GHz frequencies.

I doubt the emissions from Cell towers can disturb your reception of satellite.

Frequencies are quite different so it should not be affected.

As for the health effect. It's still debated. The consensus among scientists is that, if there's an effect on health, it's very small and has not been clearly observed yet. But you'll hear many people claim otherwise, although they don't really have anything serious to back this up.

My opinion is that these towers have been installed worldwide for more than 20 years now (yes, GSM is that old) and there's been no change in cancer rates or anything... so if there's an effect, it is minimal compared to many other things that affect our health on a daily basis.

[happyjune]

Here is a photo of the tower in question. What do you think?

The Tower is a Hutch Cat tower. But it is those monster round dishes I am concerned about.

http://imageshack.us/photo/my-images/713/sdc10662g.jpg/

[Crossy]

They are a microwave communications link and are highly directional. It's hard to say how big they are, but if they're 2m diameter then they'll have a beam width of about 0.3 degrees.

What exactly is worrying you about them, they're pointing nowhere near you.

[Mrjlh]

Having spent years designing antennas, microwave receivers and transmitters the answer in the general sense is "NO". Microwaves are transmitted and received in what is called "polarization". It can be vertical, horizontal, or circular plus several other formats I won't go into. All these issues are taken in consideration when laying out and planing tower locations. They are also frequencies ranges that are taken into account along with equipment sensitivities. All the electronic equipment needs to pass certain tests before they can be produced. You'll see these labels on every electronic device you have. That's how tough they are. Only rarely do interference problems arise. But yes, I could design a system that could ruin your day but not likely except if it was used for defensive measures only.

Now if you were to climb the tower in your picture and it's in an active state, you would be in deep trouble if you got within a few inches of the antennas. You might get radiation burns depending entirely on how much power output is involved. What's interesting is birds, insects, and many other animals make their home on top of the towers and have no problems contrary to environmentalist complaints.

The circular antennas are for data transmission and are line of sight. They have a very confined beam. the rectangular ones are usually for cell phones but not always. There are other uses for those too.

I hope that helps solve your issue.

[astral]

On a general level, don't worry about the safety aspects.

These Microwave dishes are very finely aligned and will not be pointing anywhere

near you, unless you happen to be hanging from a parachute in direct line between the towers.

They provide the telephone and internet links across the country.

A quick check of Lyngsat show that the Thaicom satellite (True)limits itself to

the high part of the Ku Band 12,272Ghz - 12.745Ghz http://www.lyngsat.com/thai5.html

whereas Measat (Astro) uses the full Ku band from 10.982Ghz - 12.745Ghz.

http://www.lyngsat.com/mea3.html

As Crossy states these beams are very narrow, but there will inevitably be side lobes,

and if TOT/CAT are using the lower Ku band frequencies then these side lobes could interfere

with reception of Astro signals. The Astro signals will be lower in strength

as Thailand is not part of the area (footprint) which the satellite was

designed to cover.

[Mrjlh]

By the way...now is not the time to solve interference issues. We just had a major solar flare which I posted the link on the news report of it. Next couple of days or weeks are going to strange I think.