News from YOTA 2019 Netherlands

Joe, MW6MQW

On the first day we were introduced to the geostationary satellite QO-100 on Es’hail-2. We found out the basics of working at high frequencies. Due to the deviation of crystal oscillators being a certain percentage of their operating frequency, they alone are not enough to ensure a stable SSB signal at very high frequencies. Because satellites need to have a stable frequency for their beacons, we can use this as a reference point to correct any instability.

To do this with QO-100, we can use the 400 baud BPSK beacon as the reference. This beacon operates at 10489.8MHz. Using this reference, any instability can be corrected. For the downlink, we used a 60cm parabolic dish with a Ku band LNB that down-converted the 10 GHz downlink to ~700 MHz. That then fed into an RTL SDR which was controlled by SDR console. For the uplink, we used an FT-847 on 70cm feeding into a homebrew up-converter followed by an amplifier to boost the signal to 4W.

Using this setup, we were able to work from Brazil to Johannesburg and beyond. Overall, this experience has got me very interested in operating satellites and using SHF which I can incorporate into my rotator project.

Category: YOTA 2019 Netherlands