Slow WiFi after installing Zorin OS 17

I have installed Zorin OS on an hp ProBook 4330s with a Core i3-2350M and 8 GB RAM. The WiFi device is a Ralink corp. RT3592 Wireless 802.11abgn 2T/2R PCIe. I found this lengthy article and tried to disable Wi-Fi power management directly by editing:

`sudo nano /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf`

and changed the value from 3 to 2, saved changes and rebooted. No change.

The result of running speedtest was

Download 28.75
Upload 11.11

Download 0.25
Upload 2.34

Any suggestions on how to proceed?

Google found nothing useful, other than that wifi card is notorious to get to work properly. Their solution was to buy a cheap USB adapter.