wifi receiver strenth vs between units and added antennas

Hi I bought a wireless n usb adapter made by ralink its small like the size of a flash drive but it has a rp-sma connection on it it came with a 5dbi antenna and I thought it a great idea to upgrade the antenna so that I could pick up at longer distances first I bought a magnetic base 9dbi antenna seemed to work good then later I bought a supposibly 26dbi antenna(looks like a 18 model but Ok i quess) its a antenna about 15 inches long with maybee 3 bumps on it.

a person I travel with bought a usb wireless G(yes G) and it can pick up things way better than my most strongest antenna with there 5 dbi antenna(again a rp-sma plug in) the difference is that her unit is much wider maybee 2 1/2in by 3 1/2 in by 1/2 in

why can a g adapter that is bigger than mine outbeat my wireless N adapter

also it seems sometimes that the big antennas dont seem to make much of a difference

also I have bought a 10 foot long cable to work with the largest antenna and I will put in my window just the antenna with the adapter down and in some situations wont pick up anything then when I put the adapter to in the window it will then pick up signals but with the car adapter one I put that on my roof and it can make a whopping difference in pickup rather that just in the car so its a so so situation sometimes the anntennas will work better sometimes I just wonder if only the usb adapter picks up signals better by it self

another thing I just rememberd is that I tried adding my antennas to there unit (alfa) and it doesnt hardly work or maybee not at all on there's but when they put there little dinky antenna back on works great

what is going on does the antennas need somesort of power source to make it work is my adapter to small to handle such antennas

please advise

I would like to have a mobile unit that picks up the longest distance possible what should I buy


thanks

know these, wireless g devices always works better than wireless N cos wireless g do have more transmit power due to their speed which is mostly 54M but wireless N have speed from 150 - 300m and as result of this "they expend more power trying to push this speed".
also due to the high speed, power is reduced so as not to cause interference, cos high speed and high power will definitely lead to overheating, instability and performance degradations so cos of this most wireless N devices have power ratings of 200 - 300mW as against wireless g that can go as high as 600mW.

if u really want range which in turn equals more TX power,, as compared to speed i suggest u go for wireless g.

also all antennas are calibrated with power gain ratings in dbi, and for antennas to achieve this maximum ratings they need to be powered up with a satisfactory amount of current passing thru the radio device to the antennas.
so if u have a big and good antenna but still is not outputting good performance then definitely the power sent to the antenna by the attached device is quite low thereby not powering the antenna properly.

that antenna is a collinear array. antennas stacked on antennas. anybody claiming more than 15 dbi out of a collinear is talking out of his tailfeathers. defies the laws of physics.

USB devices are powered by 5 VDC at 100 ma, max. there isn't enough DC power available to generate serious RF power

nothing in the post above about antennas or 802.11n is true. just ignore it all

to take full advantage of 802.11n you need multiple antennas in two different bands. I wouldn't wate my money on a USB n adapter