No I don't use one. I use a SVideo to RCa on my mixer and then RCA to an Amp and RCA out to my TVs. I use the amp because of the distance to and number of screens I have.
This is the only thing I found with reference to "Fullband".
http://fullband-tech.en.alibaba.com/ and this looks to be a Chinese company. Who did you buy it from? Maybe they would exchange it.