Forum

CWNA Book RF Math Mistake?

3 posts by 2 authors in: Forums > CWNA - Enterprise Wi-Fi Admin
Last Post: July 25, 2006:
  • By klibby
    Reply

    I just started going through the CWNA Book, and I noticed something in the RF Math section on pg 57. I think it might be a mistake, but I just want to see if it is a mistake or something I'm just missing (probably the latter).

    On pg 57 they convert 30mW to 13dBm through the following.

    1mW *10 *3 = 30mW
    1mW +10dB +3dB = 30mW
    1mW +13 dB = 30mW

    The problem I see is bold. Going by the "rule of 10s and 3s" wouldn't +3dB be expressed as a multiplication of 2 and not 3? so shouldn't 13dB be:

    1mW +13dB = ??mW
    1mW +10dB +3dB = ??mW
    1mW *10 *2 = 20mW


    Please let me know if I'm missing something or if this is a mistake.
    Thank you,
    Kyle

  • By (Deleted User)
    Reply

    Have you checked the errata file for this book at
    http://www.cwnp.com/cart/products/errata.html ?

  • By klibby
    Reply

    Yep, it's in there. Thank you for the link, I didn't know this existed, but what a great tool!

    Thank you

    (for anybody else wondering the same... yes, it is a mistake)

Page 1 of 1
  • 1