Today I received a new helical feed antenna for my QO-100 uplink system, and tested it with the power amplifier I made an initial test with in the previous entry.
The amplifier mounted indoors, and with the previous unaligned feed arrangement did give a readable downlink SSB signal for people with a well optimized RX system, and I made QSOs with it.
As I am not very good at mechanical work, I used a DX-Patrol helical feed with a hole and mounting option for some LNBs. Idid mount one LNB, with a TCXO, and modified for down conversion to 432MHz. I will use that for monitoring my uplink signal to the satellite.
Right now I am using my IC-905, driving the SG-Lab Power amplifier directly on 2400MHz, and a GPS stabilized LNB, mounted in a 60cm dish. This has quite good performance, although I want to try it with a larger dish. I have some lying around, so it's a matter of finding time and energy to do it.
Now, the test with the new feed gives about 15dB S/N via the satellite, and I can easily read my own signal. With the previous feed I could read my own signal with a little difficulty.
I can still improve the uplink signal, mounting the PA near the antenna, but it is quite nice to have it inside, so no weather proofing is necessary.
This is the test setup (with the LNB not connected).
