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WRT54G 251mW

Discussion in 'Cisco/Linksys Wireless Routers' started by Cjaiceman, Aug 11, 2005.

  1. Cjaiceman

    Cjaiceman Network Guru Member

    Does anyone know if running the WRT54G @ 251mW for extended periods of time will cause any harm down the road? I ask because I'm a little worried of how much I'm pushing the unit, but I love how far it goes. BTW I'm also using two 9dBi FMI (CompUSA generic brand) antennas.

    Right now I'm running the unit @ 230mW and it seems to be doing fine, but I don't want to hurt the unit cause I want to get at least 1 year out of it before thinking of upgrading.

    Also, should I be worried about heat build-up, or put a larger heatsink on the chip, or is fan a good idea or anything like that?
     
  2. zgamer

    zgamer Network Guru Member

    put a heatsink with a fan on it else it will get damaged within a couple of weeks.
     
  3. Cjaiceman

    Cjaiceman Network Guru Member

    where should I put the heatsink on, and/or what output can I run it at with no mods or just a fan?
     
  4. davidsonf

    davidsonf Network Guru Member

    If you are using the WRT54G as an Access Point with normal Client mode wireless units (as opposed to setting up a Point-to-Point link where you can raise the power at both ends) there is virtually no benefit to increasing the power beyond 112 mW, and in fact there may be no reason to use more than about 84 mW.

    If you cannot increase the power on both ends, you will lose your connection when the received signal is too low. Nothing you do to the transmit power will help that. If you raise the power enough that you are sure it is never going to be the transmit signal that is too weak, that's the best you can do.

    The stock power output is 28 mW, and it is probably common to have a stronger received signal when using that power. A 3 dB increase (to 56 mW) will almost certainly have an effect often (when the received signal is 3 dB higher than the transmit signal at the distant end). For those very few occasions when the signal difference is more than 3 dB, increasing the power to 3 times the original, to 84 mW, will be enough. It is doubtful that 4 times the power, at 112 mW, will ever have an effect that 84 mW would not have.

    Of course, if you have a point to point link, and can raise the transmit power at both ends, then there is something to gain from higher power.
     
  5. Cjaiceman

    Cjaiceman Network Guru Member

    Thanks for the in-detail explenation of things! :cheering: :clap:

    I heave read this and thought about it, and I have come up with a solution for my problem.

    1) I got a pair of 9dBi FMI (CompUSA brand) antennas that I put on and OMG! That alone with the 28mW power settings made a HUGE difference.

    2) I barrowed a bi-directional 2.4GHz amplifier from a buddy of mine who works at a WISP, it puts out 30dBm (1 watt) of power, plus the 9 dBi antenna and WOW is all I have to say.... And yes, it does increase the recieve sensitivity as well.

    3) I didn't know this at the time I bought my new notebook, but it seems that Gateway has a trick up their sleeve with the M320 series notebooks...
    I have been able to get wireless in places my friends and g/f can't... I've got the same card as most of them and mine works better. I've got the Intel 2200B/G but I don't know the dBi of the internal antennas.
    I've seen the wireless out perform Compaq, Dell, and other Gateways!! Reviews I have read on the internet said that other M320 users were seeing the same results. I don't know what they did, but they did something right!

    I have been running the amplifier for about 2 hours now and the WRT54G doesn't even seem to know its there, and its not even really warm... I currently have the power set to 28mW and the amplifier is connected to the right antenna connector. :drinking: :D :cheer: :clap: :cheering:
     
  6. davidsonf

    davidsonf Network Guru Member

    This is most certainly going to actually have a great effect. You will still want to increase your power though, at least to 56 mW and probably to 84 mW.

    This is not just a waste of time and effort, but eventually will probably prove to have some very negative effects. First, you should use only one antenna, not two. Unless of course you want to install two of the amplifiers.

    Regardless of that, the amplifier is not increasing your receive sensitivity. At least not unless you also happen to be forced to use 30+ feet of coax feedline between the WRT54G and the amplifier, in which case the amplifier may help receive sensitivity.

    But even then it has other problems, such as switching transients and latency. I've never used one, but I've heard horror stories from people who have the equipment to actually test such configurations.

    Your best bet is the two 9 dBi antenna, and set the power at 84 mW output.

    Incidentally I've heard of several people running the power at 251 mW and having no heat problems at all. Given that is less than a quarter of a watt increase in power, I can't see how it would cause a problem.
     

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