A little history first - When I was in the Air Force the Navigational aids were Low Frequency Radio Ranges and Non Directional Beacons supplimented by Direction Finding equipment (CRD-6) and RADAR (GCA and RAPCON) and I was a radio mechanic (AFSC 30450) for AACS (Airways and Air Communication Service) which was responsible for all USAF Air Traffic Control and Navigational Aids. When I reported to the 2020th AACS Squadron at Shaw Air Force Base upon returning from Korea they had this new navaid made by Wilcox called a VOR that provided 360 radial "beams" instead of 4. I had to maintain it but obviously I never got to study it in my training and knew nothing about it's theory of operation.
Fast forward 52 years and I'm an instrument rated pilot flying in cross country air races. In the past couple of years I have been unscrewing the elements of my Comant nav antenna to reduce drag for races. In a recent configuration I have been flying on instruments vectored for an approach with the VOR or Localizer off to the right and the indicator starts coming off the max left limit and is maybe half way to center and I start turning to lead the intercept when the controlled says you appear to have flown through the final. This happened at Baton Rouge, Louisiana (ILS) and at Taylor, Texas (VOR) in a specific altered configuration before the race at Taylor where I removed them again. I have a ramp tester for checking the system and enroute VOR checks seem OK.
I have heard the antennas referred to as dipole antennas which I would assume is a half wave center feed antenna based on the appearance but I do not know that for a fact. They could be two end feed half wave length antennas set at an angle for a specific function or there configuration may be something I never heard of back in radio school. I know all current pilots are GPS glass panel managers but is there anyone with theoretical VOR knowledge that can describe the effect of incomplete/intermittent/open connection of one element of an aircraft VOR receiver antenna?
Bob Axsom
Fast forward 52 years and I'm an instrument rated pilot flying in cross country air races. In the past couple of years I have been unscrewing the elements of my Comant nav antenna to reduce drag for races. In a recent configuration I have been flying on instruments vectored for an approach with the VOR or Localizer off to the right and the indicator starts coming off the max left limit and is maybe half way to center and I start turning to lead the intercept when the controlled says you appear to have flown through the final. This happened at Baton Rouge, Louisiana (ILS) and at Taylor, Texas (VOR) in a specific altered configuration before the race at Taylor where I removed them again. I have a ramp tester for checking the system and enroute VOR checks seem OK.
I have heard the antennas referred to as dipole antennas which I would assume is a half wave center feed antenna based on the appearance but I do not know that for a fact. They could be two end feed half wave length antennas set at an angle for a specific function or there configuration may be something I never heard of back in radio school. I know all current pilots are GPS glass panel managers but is there anyone with theoretical VOR knowledge that can describe the effect of incomplete/intermittent/open connection of one element of an aircraft VOR receiver antenna?
Bob Axsom