I doubt that you saw any Ad-Hoc connection a Client card that is configured to work with a Router is configured to Infrastructure and cannot see Ad-Hoc.
I any case there all the numbers that are given By Windows consider Speed and Signal strength are more of a Placebo than having real Value.
The way Entry Level Wireless are designed does not really yield any significant follow up reading, thus the speed and strength info comes from the drivers and software "tricks".
The only way the measure with simple means countable Signal info to use a card, that is compatible with Nets tumbler.
As for speed of transfer, only timed measure of large file can provide accurate info.
As for Mr., OP there are 802.11g Wireless Routers that are as good as the for less than $20, get yourself one.
Here $9.99 after Rebate,
http://www.compusa.com/product...t3&product_code=344137