How can I extend the (default) timeout generated by window.open() if page takes longer?

Inside own javascript code I need to open a popup using window.open(url).
Unfortunately serving url is taking longer than the javascript implementation of this open.window() function is set to wait (as default) for a url and it generates a timeout saying that “the connection is broken”.

Instead, serving thie url takes simply longer than this 30 seconds. The server is serving (because I know that, it is my server).

I am using javascript of the hosting browser, an updated firefox or chrome on android.

Window.open() is a very practical function. Instead of that I would have to implement an own popup opening function using Ajax primitives. I would prefer to stay with that window.open() function if there were a possibility.

Is there a way to modify this (hidden?) timeout for window.open() in order for this function to wait longer for the url given to it? e.g. 90 seconds or longer? I do not want to see “connection broken” I would like rather this function to wait longer than the default.

Thanks a lot in advance!