Saturday, 1 December 2018

More Es-Hail-2 LNB tests

Having been diverted onto other things for the last few days, I thought I would take advantage of the wet day (here) to finish routing the IF cable round my shack, install SDRUno on my shack PC and connect the LNB IF lead to the RSP2 Pro.  First problem....the RSP2Pro internal bias tee is only 4.7V and I need closer to 13V. Solution was to use a temporary external bias tee.
Tuning to 1008MHz and the dish pointed at the 28E slot, the 10MHz wide dispersion (span) of the RSP shows a big signal from whichever digital channel it is on 10758MHz on vertical polarisation.
Tuning between stations shows a big drop in signal level. 
Now to do some definitive tests on cold sky to ground, sun (if I can manage to point at it) and satellite noise floor. Until the Es’Hail-2 amateur transponder is activated these tests can only be indicative. 
Problem 2.  There is some concern about the OTSLO LNB internal waveguide size being too small at 10.450GHz,  causing excess loss and consequence higher noise figure.  There are claims that the horizontal probe may be further enough away from the backstop (rear short circuit) that the loss may not be so high and it may therefore be necessary for me to turn my LNB 90 Degrees to use that probe. That has some implications for weatherproofing. More testing required.


No comments:

Post a Comment