2022-Jun-29

Sun noise measurements

Here I will publish my results for sun noise measurements of my EME setups.

Date: 2015-Sep-27 . Start time of measurement, 13.14 UTC. SFI 123.

70cm noise measurement:
4×20 el LFA. Stacked vertically. Horistonal polarisation. “DB6NT MKU LNA 432 A” in the tower, 0,37dB NF and 21dB gain and ARR LNA in the shack.
6,95dB sun noise.

2m noise measurement:
2 x 15 el LFA. Stacked vertically. Horistonal polarisation. “DB6NT MKU LNA 144 A” in the tower, 0,36dB NF and 25,6dB gain and SHF elektronik LNA in the shack.
3,27dB sun noise.

Sun a bit low (only 22 deg EL).



Date: 2015-08-10
. Time of measurement, 11.57 UTC. SFI 115.

23cm noise measurement:
5m mesh dish. G4DDK LNA, about 0,3dB NF and 38dB gain.
-4dB with no LNA acitivated. +17,9 with LNA on  =  21,9 RX gain with LNA. (LNA gain minus cable losses).
Aimed at the sun: 31,9dB. 31,9 – 17,9 = 14dB sun noise. According to VK3UM EME calc I should have 15,5.

70cm noise measurement:
4×20 el LFA. Stacked vertically. Horistonal polarisation. “DB6NT MKU LNA 432 A” in the tower, 0,37dB NF and 21dB gain and ARR LNA in the shack. (the SWR curve of one of the 70cm antennas changed quite a bit after we lifted the array to its position at 23m AGL. So I suspect something is wrong with one of the antennas or cabeling).
1,2dB with no LNA acitivated. +25,4 with LNA on  =  24,2 RX gain with LNA. (LNA gain minus cable losses).
Aimed at the sun: 32dB. 32 – 25,4 = 6,6dB sun noise.

2m noise measurement:
2 x 15 el LFA. Stacked vertically. Horistonal polarisation. “DB6NT MKU LNA 144 A” in the tower, 0,36dB NF and 25,6dB gain and SHF elektronik LNA in the shack.
+3,6dB with no LNA acitivated. +31,5 with LNA on  =  27,9 RX gain with LNA. (LNA gain minus cable losses).
Aimed at the sun: 36,8dB. 36,8 – 31,5 = 5,3dB sun noise.

The SUN and LEO was not more away from each other then 20deg when I measured so on 70cm and 2m I simply rotated the array like 40-50deg on the other side of LEO, away from the sun.
Equipment used: HP 8970B noise figure meter. (using special function 9.1)