Hi,

I have a Whip antenna that is supposed to give 3dB "gain" at 915MHz.
After pulling the unit apart and studying the construction, I am not
sure what style of antenna this is.

The antenna consists of an SMA plug that has RF178 cable soldered to
centre pin and
it appears earth braid is connected to ground side of plug.

The cable goes up the inside of 1 6mm Nylon tube for 40mm and then
exits the tube and winds around 4.5T. It then enters the tube
again and runs another 80mm. At this point the earth braid is stripped
leaving only the centre conductor and dielectric to continue another 70mm
to the top of the Radome (Nylon tube).

I understand the construction of 5/8 antenna but I would not expect the
braid to be earthed.

Thanks in advance for any help.

Regards

David