I love Team BlackSheep Unify Pro series of video transmitters. But they are bloody expensive. $50 for an HV version is way too much in my opinion. Still, I own several of those. Whey on Banggood I've found a presale of Eachine TX805 VTX with SmartAudio for $16, I could not resist and I've ordered a couple of them. This is what came out of it: