I have a UPS that is producing modified sine wave. My issue is that my UPS is powering everything except my modem and I asked it in super-user: Here
The conclusion in a way was that this modified sine wave is problematic and I need pure sine wave.
Can I get a recommendation on a "converter(preferably not too costly) that converts the modified sine wave output to pure sine wave output". I can then plug my modem to this converter. I am not opting for a UPS with pure sine wave output because I have a working UPS and I am optimistic that I can make it work somehow. Let me know if the cost of the converter surpasses that of a UPS with pure sine wave output. If so then there is no point in recommending one.
My UPS model(input specs- 230VAC, 50/60 Hz, 4.5A and output specs- 230VAC, 50/60 Hz, 2.9A):