Hey captain T I would not bother with that as it won't be good enough, if your going to stick with using the supplied radio transmitter you got with the phantom then you best bet is using 5.8 for your video as 1.2 will clash with your 2.4 radio transmitter. Only thing is 5.8 is very poor for low flying behind objects.
but you can use a low pass filter, but I've never tried, also you can use a lower channel like 1.1 or higher like 1.3, but also I've never tried
FrSky Taranis EZUHF Lawmate 1.2Ghz Video gear