tirsdag den 6. marts 2018

Getting ready for AO-92 mode L/v

The satellite AO-92 was launched in January 2018. It carries an U/v transponder (uplink UHF, downlink VHF). One day in the week (usually Sunday) AO-92 runs in mode L/v with uplink 1267.350 MHz, and downlink 145.880 MHz.

I would like to operate AO-92 using the L-band uplink. I own some 23 cm equipment, which is unused right now, and can be put into service. Here is my concept of mode L/v:
Equipment for working AO-92 in mode L/v.
The upconverter is MKU 13 OTX from Kuhne Electronic. It converts 144 MHz to 1268 MHz at 1 W. The upconverter is keyed by injecting a DC voltage into the coax-cable.

The 20 W PA is based on the power module RA18H1213G from Mitsubishi. I bought the PA as a kit from PE1RKI Bert. You can find the circuit diagram and a description of the building process here.

The low-pass filter removes harmonic waves, and monitors the RF power.

The antenna is a helix-antenna for circular polarization (RHCP). As the AO-92 antenna is linear, there will be 3 dB loss when circular polarized waves are received by the satellite.

The 23 cm equipment is housed in an alu-box which is mounted near the antenna.

My 23 cm equipment in the alu-box.
I am looking forward to next Sunday where the L-band uplink is active. I hope to get some contacts via AO-92 in mode L/v!