power for GSM towers / antennas

[Tonymag]

can anyone give me information on aspects of power supply design for GSM towers / antennas? Also, is there a preferred method of lighting protection?

Regards

tonymag

 

[ccrum]

Power requirements are usually specified by the equipment vendor. Most sitew which I have built for CDMA and TDMA have required at least 200A service for all the electronics. As for lighning protection, the vendors usually spec out this too, but again it is typical to have lighning rods tied into the tower ground which ties into either a ground ring surrounding the site, or a larger buried mesh grid. Also, if you expect a lot of lightning strikes, adding poly phasors to your coax might be aggod idea as well.

Cameron

 

[jbartos]

Suggestion: Visit

http://www.anarc.org/naswa/badx/antennas/low-noise_antenna.html

http://www.aoc.nrao.edu/vlba/html/vlbahome/PM/q2-10.txt

http://www.dit.net/itnews/Article.asp?Article=1386

http://www.mikrotik.com/3projects.html

etc. for more info

 

[lkm]

Hi,

The lighning rods is a must for all outdoor electronic equipment. It can avoid the direcct damage from lighning.

In Radio system, you will have another issue on the low noise amplifier protection. The antenna is receiving the E&M signal from air. When the lighning happen, the antenna will induce a very strong, in radio system point of view, signal. It will burn out the first stage of the amplifier, low noise one, inside the receiver.

To avoid it happen, we can use the surge protectors and quarter wavelength stubs to protect it.

The surge protector contain a gas discharge tube. when the engergy induced from antenna is too high, the gas discharge tube will burn out and protect the circuit. the quarter wavelenght stub will short all the signal except the designed wavelength. The engergy will release to ground.

Generally speaking, the equipment supplier will build in their protector within the system. You need to worry on it when you are buiding your own radio system.

I hope it help.

 

[jbartos]

Suggestion: The previous posting suggestion implies a good grounding of the lightning rod. It is advisable to follow some industry standards, e.g. IEEE

http://www.ieee.org

and safety code, e.g.

http://www.nfpa.org

 

[lkm]

Jbartos is talking about the directly damage from lighting. We need to consider this issue as basic consideration.

After you have protect from the direct damage from lighting, you need to consider the sensitivity of the front-end amplifier. It may be damaged because of the induction of the lighting. The grounding system cannot avoid the induction for you but the quarter wavelength stubs still need the good grounding to let the energy go to ground.

LKM