I have now finished my QO100 Station in a way i Im happy with it.
I wanted to have a Station that i can switch on and go on Air with it. The Station should work without a Computer and it should work FullDuplex.
Let´s start on the Antenna on the Roof:
Im using a 1.2m Offset Dish wich i bought when QO100 was anounced Years ago. You can use much smaller Antennas because the Transponder is very Strong and Sensible. The Feed is a Dual Patchfeed with a RocketLNB Lens and a OCXO modified LNB to keep the Frequenzy drift as low as possible. The Feed is weatherprooved with a Canaltube and some Silicone.
I use 22m of normal 75Ohm TV Coax cable from the LNB into the Shack. In the Shack the RX Signal goes into an AMSATDL RX Mixer. The RX Mixer converts the Signal from the LNB (739MHz) into the 2m Band. The second Input from the Mixer converts the Signal up in the Range of about 1300MHz. This is used for WideBand Transponder reception with a normal SatelliteTV Receiver. The RX Mixer also has a Referenz Input where you can put a 10MHz Reference Signal into the Mixer to have a Driftfree Downlink Signal (as long as the LNB doesnt Drift…) The Mixer fits almost prefectly into the HackRF Metallcase.
From the Mixer the RX Signal goes into the 2m input of the ICOM IC-9700. The IC-9700 is also used for TX. The TX Signal is produced in the Radio on the 70cm Band. With the “Satellite-Mode” of the Radio you can setup the RX and the TX Frequency once and then the Radio sets the RX and TX Frequency automatically when you turn the Tune Knob.
On the TX Side the Signal goes from the 70cm Connector of the IC-9700 into the SG-Labs Transverter The Transverter converts the 70cm Signal with a power from 0.2-5W and puts out a 2W Signal on 2.4GHz. It also has a Reference Input to have produce a non drifting Uplink Signal.
For the Uplink Signal im using 1m of Hyperflex5 Cable and 22m of Airbourne10 Cable that goes from the Shack to the Feed. Due to big Losses on the Cable only 600-700mW of RFPower reach the Feed. But this is plenty of Power for SSB when the Signal has a good Modulation and the Antenna is acuratly pointed to the Satellite. I could also put a Poweramplifier after the Transverter if i would need that.
Everything crutial in my Setup is Frequency Stablilised. Im using an Rubidium Frequency Standard with an Output Frequency of 10MHz that i have had laying around for some time. I put it into a housing and made a Circuit that makes a 3.3V Square Signal (Circuit from DL4TMA). The cheapest thus far to get a good Reference Signal is a GPSDO from LeoBodnar. Also DM4DS has a promising project for a even cheaper homebrew GPSDO.
The Setup works very well thus far and i got good reports from several Stations around the Globe. I wanted to build a Station that works without much trouble and tuning once switched on. As far as i can say in the three weeks i use this Setup now it works great…
DISCLAIMER:
Every Product i listed here is bought by me and i dont get anything from the named Companies. I like the Products i use very well and they suit my needs but there are many, many ways to get on Air with QO100. You dont need to spend thousands of Euros and you can homebrew alot if you have the knowledge. Im not saying that my way is the way to go. Do whatever suits your knowledge and budget.
Links:
http://www.oe8hsr.at/blog/wp-content/uploads/Manuals/BuildingThePlates.pdf
http://www.oe8hsr.at/blog/wp-content/uploads/Manuals/PatchFeedAssembly.pdf
https://uhf-satcom.com/blog/patch_antenna
http://www.oe8hsr.at/blog/wp-content/uploads/Manuals/QO100RX.pdf
http://www.oe8hsr.at/blog/wp-content/uploads/Manuals/QO100TX.pdf
Best wishes Hoonse