Weak or ‘snowy’ picture at close (10meter or so)
range
Usually indicative of a faulty antenna, SMA connector or
transmitter.
An internally broken antenna can be annoying as it is
essentially unfixable, having to buy a new one is the only
realistic solution, however a couple of basic tests can
usually determine where the fault lies.
Remove the antenna and see if this affects the reception,
if not then this means it is on the receiver end, continuity
test across the middle pin and outer ring where it screws
onto the monitor. If there is a short here, the antenna is
faulty and should be replaced.