The LNB for the OSCAR 100 downlink receiver was sealed after the modification, and has replaced the temporary one mounted at the 60cm dish.
I still need to complete the indoor buffer circuit, but some preparations for other stuff had to be done first.
Next comes the transmitter up-converter to 2.4GHz. I am still waiting for a passive mixer module specified up to at least 2.5GHz, and they are on the way.
The configuration will likely be as follows:
432/439MHz transceiver frequency -->
attenuator and the LO *) signal -->
Passive Mixer -->
amplifier, probably made with the RF amplifier of a modified (filters) MMDS converter (when using 432/439MHz as IF, these filters should provide sufficient image rejection) -->
20 - 50mW amplifier -->
1W amplifier -->
cable to feed antenna system -->
"8W" amplifier, likely providing 4-5W at the feed -->
feed antenna --> dish antenna **)
*) LO signal provided by a ADF4350 synthesizer board controlled by an Arduino Uno board -->
about 20mW amplifier at 1962/1968MHz.
**) experiments with other antennas will be done. I already have a panel antenna for RHCP and a 1m long yagi, as well as a cheap, probably not very good, 17elm yagi about 40cm long, as well as a PCB LPDA antenna for test as a feed antenna.
This should provide a decent up-link signal to OSCAR 100, useable for SSB, and certainly for CW or digital modes.
The building activities will be halted for a few weeks, but mid april they should resume.
More than enough experimentation before the refinement of the system starts.
The buffer for the RX reference LO should be ready and tested soon, though.
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