UPDATE: The DXpedition has been postponed by the Venezuelan Navy. Check back for further updates.
The YX0V DXpedition to Aves Island, scheduled for August 31, 2016 – September 10, 2016, will include satellite operations. Aves Island, a dependency of Venezuela located west of Dominica and Guadeloupe in the Caribbean Sea (grid FK85eq), is currently the 17th most wanted DXCC entity on the Club Log DXCC Most-Wanted List and was last on the air in 2007. It was active on satellite during the YV0D expedition in 2004, but only three QSOs were made before the DXpedition was cut short due to rain.
Happy 20th Birthday to Fuji-OSCAR 29! FO-29, known as JAS-2 (Japan Amateur Satellite #2) prior to launch, was built by the Japan Amateur Radio League and launched on August 17, 1996 from Tanegashima Space Center on an H-II launch vehicle into a 1,323 km x 800 km orbit with an inclination of 98.5 degrees. In addition to a 100 kHz wide analog Mode V/u (JA) transponder, the satellite also includes a packet BBS and digitalker. While the packet BBS and digitalker are non-functional, the analog transponder continues to provide excellent service to the present day.
JAS-2 prior to launch. The satellite is a 26-faced polyhedron with a mass of approximately 50 kg.
With an apogee of 1,323 km, FO-29 provides satellite operators with excellent DX opportunities every few months when the passes over a certain area are at or near apogee. Intercontinental QSOs are regularly reported, including between Japan and Alaska as well as North America and Europe. Although the theoretical maximum range at apogee is 7,502 km, the excellent sensitivity of the transponder as well as it’s strong and solid 1 watt downlink signal allows that distance to be stretched when the conditions are suitable. The longest distance QSO made via FO-29’s analog transponder occurred on August 27, 2015 with an unscheduled 7,599.959 km contact between KG5CCI in Arkansas and F4CQA in France.
The sensitivity of the transponder and Mode V/u configuration also allow for the effective use of minimal equipment. QSOs have been reported using a single Yaesu FT-817 transceiver and the stock rubber duck antenna. Taking advantage of the large footprint and ease of use, the K1N DXpedition to Navassa Island made a total of 29 QSOs during two passes of FO-29 on February 12, 2015 using a single Yaesu FT-817 along with an Arrow antenna, activating that extremely rare DX entity on satellite for the first time since 1978. To this day, FO-29 remains the most widely used linear transponder satellite and an ideal satellite for beginners looking to become active on the linear transponder satellites to try first. The FO-29 control station maintains a blog (in Japanese) at http://blog.goo.ne.jp/fo-29. The JARL also offers an award for confirmed QSOs with ten different stations via FO-29.
The K1N Navassa Island satellite QSL card, showing operation via FO-29 using a single FT-817 and Arrow antenna.
Amater-Satellite “Fuji” Award available from the JARL for confirmed QSOs with ten different stations via FO-12, FO-20, or FO-29.
The Argentinian earth observation satellite ÑuSat-1 carries a linear transponder built by AMSAT Argentina. The satellite was launched on a CZ-4B rocket from Taiyuan Satellite Launch Center in China on May 30, 2016 into a 500 km sun-synchronous orbit with an inclination of 97.5 degrees and a Local Time of the Descending Node (LTDN) of 10:30.
The AMSAT Argentina U/v inverting transponder, named LUSEX, has an uplink of 435.935 MHz to 435.965 MHz and a downlink of 145.935 MHz to 145.965 MHz. Total power output is 250 mW. There is also a CW beacon at 145.900 MHz with a power output of 70 mW.
The transponder and beacon are currently active over Latin America and Europe.
First, we have a dual-band feed design update from Paul Wade W1GHZ.
He reports that what he’s come up with looks like it would work pretty well for an offset dish like the DSS dishes, with good efficiency at both bands. Simulation says the isolation from 5.8 GHz to the 10 GHz port is about 80 dB.
Performance plots are attached. He is going to work up a sketch for 3D printing.
He recommends a filter (like the ones in his QEX articles) that can easily provide 60 dB of second harmonic rejection. He believes that the second harmonic from any decent amplifier is 20 or 30 dB down, so that’s at least 80 dB down. Unless the signal is actually inband, a signal that far down won’t hurt.
He added that as for push-pull amps, we may be underestimating the difficulty of keeping them balanced at microwaves. Using a push-pull amplifier as part of the dual-band solution may not provide the performance we need.
Second, there’s plenty of action in the transmitter RF chain with results from measurements at the VHF super conference. Thank you to Eric Nichols, Mike W4UOO, John Petrich, W7FU, John Toscano, Mike Seguin and several others for stepping up to volunteer on this part of the project. We’ll be increasing our use of google forms to coordinate parts of the project, maintaining a list of all the forms on github, and possibly setting up a webpage to increase project findability.
Third, San Diego Microwave Group demonstrated the results of a project that Drew and Kerry Banke have been working on these last couple of weeks. It is the combination of a $4.24 Arduino processor board with a $29 ADF4350 PLL board to provide a programmable fixed LO in the 137-4400 MHz range. Once programmed, this set of off-the-shelf boards comes up on frequency at power up. The programming software utilizes the Analog Devices ADF4350 evaluation software to calculate the PLL data. This is entered by hand in to an Arduino program(sketch) written by Drew. This then is uploaded to the Arduino and that’s it. Kerry reports that the software is easy to use and free. Check out this video report from Paul KB5MU.