Small Update on the QO-100 Uplink.

 The uplink signal using the single patch antenna resulted in quite a weak signal on the satellite, There were even instances where a station simply continued calling CQ while I called them, I could easily hear my signal on the downlink, but it was not strong enough to get any attention.

While I am planning on improving the set-up with a bigger dish and with a helical feed antenna, I was browsing for QO-100 feed antennas, and came across this 4-patch feed which has circular polarization. I realized that I have a small WiFi antenna, a so-called 14dBi panel that I estimated having 4 patches phased together, a bit like the feed in the link, albeit this just with linear polarization.

I taped the panel to the dish, got it aligned, and sure enough, the signal is a few dB stronger than before.

Further, I had removed a 10dB attenuator between the 432MHz TX and the up-converter, and when I received a report on a spurious signal on the CW signal I tested with reduced power, and sure enough the distortion disappeared and the tone was clean again. The S/N was even better, now close to 10dB in SSB bandwidth, a quite comfortable level for receiving a CW signal.

Further, after some email exchanges with PA1GSJ, and some of my previous thoughts, I will be testing some more improvements on the uplink.

- a circular polarized feed antenna, such as a helical.

- replacing the low cost satellite cable with RG-6 may provide a sufficiently low loss to eliminate the "driver" Edup amplifier and the extra filter in the outdoor unit.

- a larger dish for the uplink is contemplated, such as a 100cm one.

- I do have a 80cm dish, and I might replace the 60cm receive dish with this one.

- a better reference oscillator (set) 10/25MHz is on the way, so I know better which frequencies I work on

- a second receive converter , so I can use my dual band 2m/70cm TRX in satellite mode (70cm for the uplink and 2m for the downlink), and having the TX and RX tracking.

This is quite a list, so I will take my time and slowly improve/optimize the satellite system.