isn't the problem.
I looked on Ebay. I found the "Wagan Tech high efficient model #20072
" and the "Power Express". The Power Express is advertised as "This inverter is made from the same factory as the Coleman brand".
It's only $195 US and comes with a wireless remote
control. Maybe to change channels?
I buy a lot on Ebay but I stay away from any mystery brands. The risk of getting junk is just too high.
is very tough on an inverter. The motor
has a heavy surge when it starts and it runs many hours a day.
Switching to a pure sine unit is not necessarily the right solution. If the fridge ran fine on the modified sine it won't be better off on pure sine. It would be a much better idea to get a very high quality modified sine unit than try to go with a cheap
pure sine unit.