Some more observations. Clare VE3NPC
----- Original Message ----- From: "OZ1MY" oz1my@privat.dk
I do not know about other areas of the World - but here over Europe the background noise on the downlink is very high. Did not experience the normal FM quieting effect by increasing the uplink power. I do not understand that - any ideas ? Is AO-16 making the noise itself ??
Yes the noise is coming from AO-16 and is readily observed on my home brew spectrum display unit. Its amplitude (QSB) varies at a cyclical rate of about 14 seconds which corresponds to a spin rate of close to 4 rpm. The peak to min on my FT-847 can be up to 6 S units depending on elevation distance and angle with the maximum difference occurring at higher elevations.
The polarity of the downlink antenna is difficult to make out. I thought it is RHCP - but Mark says LHCP. For me on the passes to the East RHCP is best ! Passes from the South - LHCP is best ! That is a general observation - some times it helped to switch during the passes. AO-16 might be tumbling a lot ?
My observations agree with this as the sat approaches and recedes. However during the middle of a high elevation pass when one polarity is at a minimum the opposite polarity is at a maximum. I have 2 x 10 turn helix ants on RH and a single 10 turn helix on LH with coax relay switching.
Have fun and thanks to the team and the builders.
73 OZ1MY Ib
VE3NPC Clare