DRS6A Vertical Beam Centerline

[RickVicik]

The vertical beam width of my DRS6A is 22 degrees. I want to measure exactly how it is aimed with respect to my boat.

It is easy to estimate the location of the starting point of the beam inside the antenna housing within a few inches, but exactly where that beam is pointing in the vertical plane is difficult to determine because of the smooth curved surface of the housing.

The plane of rotation of the antenna seems like a good reference for making an accurate measurement of beam vertical aiming. Is the beam centerline parallel with the plane of rotation? i.e. 11 degrees up and 11 degrees down or is it some other split?

Or is there some other reference line or plane that I should be using?

---rick

 

[Flatline]

RicVicik
Thank you for your inquiry.

"Is the beam centerline parallel with the plane of rotation? i.e. 11 degrees up and 11 degrees down or is it some other split?"

Yes; you are correct. with a vertical beam width of 22 degrees the radar transmits 11 degrees above and 11 degrees below the zero degree-horizontal plane. we measure the transmitted energy to the 3db point on each side of the transmit (total of 6db) and this provides the measurement of the beam width. Outside of this measurement the transmitted energy sharply decreases.

 

[RickVicik]

Thanks very much. That is exactly the information I needed.
---rick