I do not know what to tell you about an inexpensive no name welder
off the internet. I have never used one. At those prices I just
can’t imagine they could be very controllable or consistent
especially at low power settings and with difficult metals. There
are two great proven brands in the jewelry industry that will easily
deliver consistent and repeatable welds on all metals. The PUK 4.1
welder by Lampert of Germany and the Orion 150s by Sunstone USA.
Both great machines. There are plenty of tutorials and YouTubes out
there on both Brands.
If the online machines don’t call for argon or can’t accommodate
adding argon you will definitely not get good welds.