Thread: Target Camera Revisited

Originally Posted by MGNZ

https://youtu.be/UyTaqD3qO4g

That looks like a design that forum members could have a go at replicating. The driven element is a full-wave loop with unbalanced feed, directors all the same length, I wonder if the designer has quantified the electrical behaviour ? Without building one and testing, it is not so easy to predict, though it looks about right for maybe 9-10dBi forward gain... worth trying.

The reason I'm harping on a bit about the antennas is that all the other hardware parts have performance that is fixed; the components are purchased in from Banggood or AliExpress, hooked up, and a picture received. It is the choice of antennas when assembling a TargetCam that has the largest influence on whether the system works well - or does not - across the distance required.

A problem if using the "vertical" antennas supplied with the FPV transmitters and receivers, and one that might not be obvious, is that while the system gain over the distance between the shooter and target may in theory deliver a good picture, these omni-directional "rubber duck" or stick antennae are prone to picking up a multitude of reflected signals that result in the dreaded multi-path interference. Very small changes in the position of the receiver or things close to the receiver (think you or the rifle etc) can cause the video to repeatedly drop out. A directional antenna at the receiving end is a good thing not just because it provides some forward gain but because it suppresses (for want of a better term) the pick up of signals from directions other than from the target, and makes the quality of the link more robust. If using the supplied stick antennas, having your shooting position with the TargetCam receiving antenna out in the open and clear of the ground will be better than near structures, particular metal ones.