RadioJove system repairs and mods
Last week we noticed that the cable connected to the southern dipole antenna of the RadioJove system was broken/disconnected. Not a surprise as it has been up for over six years now (first installed 2011 April 29th). On Wednesday 2017 Nov 8th, it was repaired and reconnected to the dipole antenna. We also took the opportunity to raise the antennas to aim the beam to a lower elevation.
Because of the low declination of Jupiter the last year and going forward for a few years, the dual dipole antenna was raised from 10′ to 15′. This in effect, steers the peak sensitivity of the receiving beam to more closely match that of Jupiter.
From the radiojove 1.2 antenna kit manual from 2012, Jupiters declination has gone from a peak of 23 degrees in 2014, to -10 degrees today and will be dropping to -22 degrees in early 2019 through to 2021.
Jupiters max elevation is currently around 40 degrees and will drop down to 25 degrees in early 2019. With the antenna at 10′ and using a 90 degree phasing cable the beam centre was approximately 60 deg elevation. With the antenna at 15′ and the same phasing cable, the beam centre is now 49 degrees elevation. Ideally, if we could, we would remove the 90 degree and add a 135 degree phasing cable to lower the beam centre to 42 degress.
So now we wait and see. Jupiter transits our site around 11:00 EST and if it is within the antenna beam of greatest sensitivity, we should see a signal. If not, then we start testing the system and checking coax connections.