On March 30, 2016, the radio amateur club was visited by Fabio, IK2SOB, and his dear friend Mike. After antenna inspection on the roof, the shack was visited. Radio conditions were rather poor today, but (at the very least) two QSOs with IZ6MVK and IU5FIA were successfully completed on 40m in Italian language.
Today was a beautiful sunny day and the institute’s roof was calling for another set of X-band trials. During the morning Viktor and I arranged a sked for 16:00Z between OE1XTU and OE1VKW on QRG 10.3682 GHz. The photo below shows the improvised set up of the X-Band transmitter on the institute’s rooftop antenna platform.
The X-band transmitter is visible on the right hand side: the FT-817ND transceiver is tuned to QRG 432,2 MHz and the Kuhne electronic transverter G3 converts up from 432 MHz to 10.368 GHz and feeds its output to a 16 dBi horn antenna. The FT-817ND delivers 5W output and we inserted a 10 dB attenuator to protect the input of the transverter.
On the left hand side, the FieldFox is visible which runs a spectral analyzer connected to an identical horn antenna. This is our local transmitter output check.
Gerald Artner assisted with the roof set up today … and, yes, this lead to first success.
We started with „AM“ modulation and the default settings on the radio. Viktor, OE1VKW, received our signal with a roof antenna at his QTH (around 6,1 km distance to OE1XTU with LOS blocked by the left block of the AKH – the big hospital). Viktor reports a clearly visibly rather noisy carrier with 20 kHz width and approximately 20 dB above the noise background.
Next, the transceiver was switched to „FM“ and the signal became significantly broader in extent (50 kHz of bandwidth). Also „USB“ was tested, but not quantitively evaluated. Many thanks to Viktor, OE1VKW, for helping us with these initial experiments.
73 de Chris, Gerald, Robert, Arpad.
First tests at the roof of the institute (see foot below) were only partially successful: reception level of the OE1XGA beacon is S9+, but the first transmission test to OM Viktor, OE1VKW, mysteriously failed.
In the meanwhile we measured that our 16 dBi horn antenna is well matched, |S11| < -15dB, and the transverter delivers approx. 100 mW output power with the current settings of the FT-817ND.
Two of these X-band set ups are used for practical exercises by electrical engineering students in the Master programme “telecommunications” at TU Wien within the course “centimeter- and millimeter waves“.
73 de Chris, Robert, and Arpad
The radio amateur club is preparing for its first QSOs in the X-Band (Wavelength 3cm). The foto below shows the most basic Rx set up: The 16 dBi horn antenna picks up the 10.368 GHz signal and feeds it via a WR90 adapter and coaxial line to the „Rx“ input of the transverter (Kuhne electronic MKU 10 G3 432 Professional). The transverter converts it to „IF“ at 432 MHz which is in turn forwarded to the all-mode QRP transceiver (YAESU FT-817ND).
First Rx tests were carried out successfully during March 07-08, 2016 with the X-band beacon OE1XGA operated by OM Wolfgang OE4WOG, QRG 10.36888 GHz, QTH Vienna, Kahlenberg, LOC JN88eg. The distance from OE1XTU to OE1XGA is 9,0 km. The beacon is clearly audible in both line-of-sight and non-line-of-sight conditions.
Next tests will be carried out with OM Victor OE1VKW.
Two of these X-band set ups (one for Tx, one for Rx) will be used for practical exercises by electrical engineering students in the Master programme „telecommunications“ at TU Wien within the course „centimeter- and millimeter waves„.
73 de Chris, Robert, and Arpad