30.0°W XTAR-Lant

All LHCP 1.5m PF Dish
4 turn helical feed (under illuminates dish)
1.6dB NF LNA (Miteq + mil surplus)
8.5GHz DRO down converter

Using 1.2m Channel Master with LHCP feed and ~2dB NF LNA

One feeble lock today on 2.4PF

7430L back. Today's scan on 1.2m

1.2m dish 1.3dBNF LNB

RHCP scan (see also this post). Not normalised, there is a mixture of data and GS.

I'm not sure how good the X-polar rejection is at 7.5GHz as the system is optimised for 8.4GHz.

I'm not getting much rejection of LHCP as 7429MHz 1000ks/s is quite strong. However, I am seeing a generally different plot to the previous LHCP ones.

I can't get 7677.75MHz to lock. There a few narrow signals close to it but I don't think they are preventing lock.

I tweaked the polariser to get best nulls for L & RHCP. However, the 8.45GHz polariser only gives about 7-10dB rejection of the opposite polarisation. Despite this, it shows that the 3 lockable signals are all LHCP.