lmr 195 or lmr 400

Discussion in 'General Discussion' started by davidbrantly, Sep 25, 2006.

  1. davidbrantly

    davidbrantly Guest

    Can someone tell me which cable i shoul use, lmr 195 or 400? I am trying to install a wireless network for my campers in my campground. I have purchased a wrt54g v.3 with ddwrt software uploaded on it. I am purchasing a 45 degree Sector Panel Antenna(15.8 dbi made by super pass) and do not know which cable has the least impedence?!? Which cable should i use? Any experienced people that have installed a system like this please feel free to comment!
  2. HennieM

    HennieM Network Guru Member

    Both LMR195 and LMR400 are 50 ohm impedance. LMR400 has lower dB loss over the same distance. If you Google a bit, you would find some tables (I can't find it right now ;-(. However, LMR400 is a much thicker cable, and therefore more difficult to work with. It also puts more weight on whatever it is connected to (when it hangs), and most importantly, usually costs quite a bit more! If you go a short distance, like less that 5m, the cable type is not so critical, and you would not notice the difference.
  3. martyy2k

    martyy2k Guest

    lmr-195 or lmr-400

    Hi Group... well as for the right choice, it's all dependent on what you want. As a matter of fact, 5m of cable is 16ft and that does not seem to be much. Now if you look at loss, the LMR-195 will give you a loss of 3dB @ 2.4Ghz. Now, that is about a 50% power loss! Add to that connector insertion loss of about 0.15dB/connector depending on quality you buy and connection you make we now end up with a 3.3dB loss or 54% loss. So on a 2.4Ghz system running 84mW, that means you are actually getting to the antenna is 38mW.

    Now do not forget that this also applies to the received signal to the router or access point. You are actually cutting in half it's received signal. You mention you are using a 15dBi gain antenna, that is great.

    With the lmr-400, here is the loss:27.4% or 1.4dB! you are now sending 61mW to the antenna. So couple this setup with the 15dBi antenna and you are in buisness. You will now get good gain with the antenna, without losing receive capacity and also increasing range and signal quality.

    We all know that the better the signal, the more speed you will be running at.

    Good luck!

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