My current antenna setup, your thoughts on my situation?

Hello. I am pretty limited in what I can and want to do when it comes to antennas but I could get a different antenna, put it somewhere else in my room etc. I am just not sure if anything can improve on what I have currently.

This is my current antenna: Imgur: The magic of the Internet

It is the antenna screw-on part from a cheapo DTV dongle and screwed onto the larger base that I got with the NooElec NESDR bundle. I have trimmed the whip so that the full length from tip to base of screw area is 69mm. It is sat on a metal circular 1mm thick 15cm diameter plate because this was the closest “off the shelf” round metallic thing to use as a ground plane, as closely as I could to getting a 1/4 wave radius. It is just a tad less than 1 meter raised from the windowsill on my upstairs bedroom. Total height above ground level is about 4.7 meters, but it is indoors in my window as you can see on the image, suspended from an unused net curtain line and partially resting on the ledge of the top window to take some of the weight off the string.

The view out the window is due east and to the north and east are higher than me by at least 25-30 meters, which is why I believe my coverage is lobsided towards the other compass points, although I still see planes from a good 40-60 miles north and east.

Coverage image for past 24 hours from the page on FA: Imgur: The magic of the Internet
(ignore the super long range hits, they are from a bogus reading which said it was over 2000 miles away?!?!?

I am consistently getting a good 100 miles range and routinely get 120+ miles to the south west. A few have been 140+ miles.

If you could let me know what you think of my setup and if there are any other options for me, indoors without needing drilling, screwing, etc etc, just simple improvements like a new antenna choice or something, I would appreciate it.

I have purchased some parts to try and make a coketenna but I am honestly not sure if it will improve on my current performance. Any thoughts are welcomed.

Thanks.

The cheapest way to improve the setup is to build an “coco” antenna. Built my first antenna and doubled my coverage - #13 by jepolch

I have seen that those are very hit and miss, people can make good antennas but getting those right, is a skill (I think). I am mainly interested if what I have could be improved upon. I am thinking of a FlightAware antenna because it seems it could be put indoors, but I do not know how big of a difference I may see, compared to the one I have. If anyone has experience with such comparisons of apples to apples, indoors this kind of antenna vs that kind, that would help a lot.