I think you may be misinterpreting the Signal readings.
Originally Posted By: AirRadar Support Wiki
Signal Strength (sometimes known as RSSI), displayed in AirRadar as a percentage, is how strong the connection to the wireless network is. The farther away from the base station, router, or relay point, the lower the strength will be. Other physical factors (such as walls, people, furniture, etc.) between this computer and the network also affect signal strength.

So there is no direct relationship between the Signal strength percentage as reported by AirRadar and other Wifi apps and network data rate or speed. The most direct effect on network speed is the version of the 802.11 protocol being used. If your connection is using..
  • 802.11b the network data transfer rate is limited to 11 Mbps (note that is bits not Bytes).
  • 802.11g networks can get up to 55 Mbps
  • theoretically 802.11n can get up to 150 Mbps (but I would not hold my breath expecting that high a data rate).
There is an indirect effect of signal strength on network data rate however. A weak signal is more prone to transmission errors resulting in more frequent retransmission of network data packets to achieve data reliability.

If your Netgear router and repeater support it, try configuring them to create a 802.11n network. Any Mac made in the last four years is capable of 802.11n and theoretically 802.11n is capable of up to three times the data rate of 802.11g and twice the range. 802.11b/g operate only on the 2.4 GHz band but 802.11n can operate on either the 2.4 GHz or 5 GHz bands. Again if your Netgear equipment will support the 5 GHz band give that a try. In some cases the 5 GHz signal will punch through where the 2.4 GHz will not go or vice-versa.

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