The power handling is less than version 2 but better thane version 1. It is better due to the amount of loss in the helical that version 1 suffers. The efficiency is better due to the coil location. Having the centre of the loading coil approximately 45% of the way up (measured from tip of the rod to the ground) reduces coil loss & increases radiation efficiency. The use of a whip is for weigh issues when standing the PVC pipe up.

My plan is to cap the top of the PVC pipe with the appropriate cap from the plumbing supplies. Then drill a hole needed to install a helical base mount and screw on a stainless steal VHF Low band whip. This is not drawn.

The large difference here is in comparing between version 2 and version 4.

Version 2 can cop more power and free stands. But needs the added expense of a power pole. The cost of which is depending on it's size.

Version 4 doesn't cop the higher power. It is lighter and can go on a tin roof. It needs to be guyed as per version 1.

Version 4 compared to version 1 will cop a little more power and be a little more efficient.

After some field testing version 1 might be scrapped! More on this later.

PVC pipe comes in 6.5m lengths & the VHF Low band whip is about 1.2m (I think). Vertical height is everything as I've mentioned before. Version 5 of this might be two lengths of PVC pipe glued together (13m) and held up with 4 lots of guys. That would put the coil at the top of one piece. Don't forget the use of PVC means we can wind the coil on it any where we need to as the pipe is the coil former. This can't be done with steal pipe (or any metal).

Cheers

Tatey