App Syncing

Hi,

I have a question concerning syncing my iPhone/iPad with iTunes.
Right now on both devices the apps are synced via iTunes. So every time I download a new App directly to my iPhone the moment I open iTunes it downloads the App to or when I sync it transfers the updated App from the Phone to the PC.
My question: Is there a way not to sync the apps via iTunes (so I can delete them from the Computer, because they need a lot of space) and not to lose all the Apps on the iPhone when I sync it for the first time after unchecking the box "App sync" in iTunes. Last time I tried this (it was several years ago with an iPod touch) unchecking the App Sync meant that all Apps get deleted on the device.
I hope it's clear what I tried to describe If not just let me know so I can make it clearer

 

Thank you for the help!
Now, my iPhone is connected to my PC by the cable.
If I uncheck "synchronize Apps" in the iPhone specific section will they be deleted from the iPhone when syncing the next time?
If yes how do I prevent them from getting deleted? I don't want to lose all the data.