Amateur Radio Satellite Station W5PFG chronicles his experiences, highlights some poor behavior, and admits a couple of mistakes he's made while operating. The opinions expressed on this page are just opinions. This is meant to be a fun blog. Don't take it too seriously.
On Thursday, May 26, I made a visit to gridsquare EL58hx in far southeastern Louisiana. It was a great adventure. I intend to write more detail for a future article but I wanted to share a few sneak peeks with my blog readers.
There is plenty of GoPro and DJI Phantom3 footage. I intend to put together a short montage available on YouTube at sometime in the future.
Until then, here are a few pictures of the operation:
Doing secondary GPS check before we dropped anchor.
Drone footage of me working a western pass.
More drone footage of me working a western pass.
Working an eastern FO-29 pass.
Another view to the west across the Gulf of Mexico.
I have made my recordings available from this past week's special event commemorating the 120th anniversary of Tomsk Polytechnic University and their CuteSat awaiting deployment aboard the International Space Station.
In May 2016 Tomsk Polytechnic University celebrates its 120th anniversary. As part of the celebrations from 0755 UTMay 10 until 1005 UT May 11 Tomsk-TPU-120 will be activated in the ISS and will transmit a greeting to Earth inhabitants, recorded by students of the university in 10 languages: Russian, English, German, French, Chinese, Arabic, Tatar, Indian, Kazakh and Portuguese.
The greeting signal will be transmitted once a minute on 437.025 MHz FM. One of the Kenwood transceivers (TM D700) on the ISS will provide a cross-band relay, re-transmitting the signal on 145.800 MHz FM.
Between April 11-14, 2016, the ISS had another SSTV event. I was away on business but I managed to capture all of these images with my station on autopilot.
All images were decoded live using MMSSTV straight from the USB soundcard interface on my Icom IC-9100. Normally I would record everything via SDR (FUNcube Dongle Pro+) and play back the images through something like Virtual Audio Cables but I was very busy and didn't have time to schedule recordings in HDSDR.
Quite a few of these partial images were on passes where the elevation of the ISS at my observation point was never over a degree.
First Series of Images Commemorating 15 Years of ARISS
March 2016, my family took a short holiday to the Quachita Mountain National Forest on the Arkansas/Oklahoma state lines. The grid square is EM24. We were camping in our travel trailer at Queen Wilhelmina State Park.
During the week, Dave KG5CCI came to visit. He lives in Little Rock in neighboring grid EM34. Dave has some family in the area so it was convenient for him to come play in the mountains with me for one afternoon.
While we didn't have the opportunity to work many satellite passes together, we did have a lot of fun on one AO-7 and one FO-29 pass. Dave made a good contact with the UK on a ~2 degree window from one of the many overlooks along the Talimena Scenic Road (Ark. 88.)
We stopped along another overlook as we made our way to camp and worked one FO-29 pass together. He setup his station a few meters away.
During station setup, we had a little fun demonstrating polarity (mis)alignment:
We worked a nice FO-29 covering most of North America. At the end of the pass, Dave and I played a little bit with "how low could we go." With me using the short Arrow and Dave using the full Alaskan Arrow, we were able to work each other below -1 degrees elevation. You can hear us talking about it to each other VIA FO-29 on this little clip:
KG5CCI - Icom IC-821h and Alaskan Arrow (10 ele 70cm, 4 ele 2m)
W5PFG - Icom IC-821h and Short Arrow (4 ele 70cm, 2 ele 2m)
Folks, Dave KG5CCI has a great place to play radio. You can see how this location is excellent for stretching the footprint and making extreme DX contacts in his backyard.
Over Easter weekend 2016, the ground station team for EO-79 activated the FUNcube-3 transponder on board for amateur radio use worldwide. I managed to make several contacts over the weekend. I worked two passes from home using my normal Icom IC-9100 station and two passes operating portable with my Icom IC-821 and Arrow.
During both passes from home, I recorded audio locally using Audacity software and simultaneously recorded the entire transponder passband using a FUNcube Dongle Pro+ and HDSDR software.
You can see some of the fading in this screenshot from HDSDR:
Coincidentally you can see AO-73's beacon. It was passing over my station at the same time as EO-79. Notice the "flaming comet" to the right side of the waterfall. I'm not sure what is it's source. I listened to it and it sounds like FM noise.
You can clearly see several QSO's taking place on the transponder. This is why I love SDR and have posted about it previously on this blog.
I noticed with SatPC32 that using computer control, I had to adjust my uplink +13,500-800. Like AO-73's transponder, this one is a little unstable due to temperature on board, so you are better of manually tuning. However, you can easily tune with the computer as long as you have your fingers ready to make adjustments during the pass.
Take a listen to a snippet from the first EO-79 pass I worked over the long weekend:
Overall, I found EO-79 relatively easy to work. It does tend to fade/shift polarity a little more than AO-73 but signals are overall strong. I hope that it can be made available to the amateur radio community for permanent use eventually.
DISCLAIMER: This entire blog post is focused on manually tuning your satellite radio to make contact via linear transponders (SSB/CW.) If you are using computer control of your rig for Doppler Shift correction, some of the comments below will not apply.
Most popular satellite radios such as the Kenwood TS-2000, Icom IC-910h, and the Yaesu FT-847 offer a mode to "track" satellite frequency movements. There are normally two types of tracking, Normal and Inverse. Your rig or software may refer to Inverse as Reverse.
Inverse tracking moves your uplink and downlink frequencies in opposing directions. If you move one VFO up 10 kHz, the other VFO will go down in frequeny 10 kHz. The majority of amateur satellite transponders in orbit utilize inverse tracking. Inverse tracking is the most common practice.
Normal tracking moves your uplink and downlink frequencies together in the same direction. Only one satellite operational today does this - AO-7 in mode A. (note: Mode B is inverse)
It is important you have the correct tracking mode selected for each satellite before you go any further.
Most of the manuals for true satellite radios explain how to find your own uplink or downlink signal. I won't go into that on this blog post. I want to cover an important topic: DO NOT DEPEND ON YOUR SATELLITE RADIO'S LOCKED VFO'S TO KEEP UP WITH DOPPLER SHIFT. I intentionally bolded and capitalized that entire sentence. It is very important. You will always need to make manual adjustments as long as you aren't controlling your rig's VFO's by computer.
The radio's internal VFO locking does not really have anything to do with Doppler shift. It simply locks the VFO's so that they move equally with each movement of the main VFO knob. This will not properly tune your station to the same frequency as another station on the satellite passband.
If you try to have a QSO with someone while your VFO's are locked, you will look like a lid because every time you move your VFO knob, the uplink/downlink frequencies are technically moving away from each other in an unnatural manner, not how Doppler shift is affecting the uplink/downlink relationship.
It's fine to lock the VFO's and move to another part of the passband but it is not sufficient for staying in one place and having a QSO. Once you "land" somewhere, unlock and tune the sub or main band VFO depending on the satellite mode (V/U aka J or U/V aka B.) This is where the Updated One True Rule comes into play.
Remember, we tune the higher of the two frequencies. Examples:
AO-7, AO-73, XW-2 linear transponders: tune uplink
FO-29: tune downlink
If you lock the VFO's, you will be tuning BOTH!
(that's okay if you are using computer control and it's done automatically and properly)
I highly recommend reading "The One True Rule for Doppler Tuning" by Paul, KB5MU and the updated "Bringing the One True Rule of Doppler Tuning into the 21st Century" by Alan, WA4SCA.
Buy a copy of AMSAT's "Getting Started With Amateur Satellites." It covers this topic well and includes the above two abstracts.
Amateur radio enthusiast Paul Stoetzer recently made history
by operating amateur radio satellites from the National Mall in the United
States’ capital city, Washington, DC. Amateur radio operators are licensed to communicate via Orbital
Satellites Carrying Amateur Radio (OSCAR) and have been building such
satellites for over fifty years.
The American Radio Relay League (ARRL,) the national association for amateur radio in the United States is sponsoring
an initiative to help the United States National Park service commemorate its
100th year in operation.
Amateur radio operators are encouraged by the ARRL to operate portable
stations at National Park Service Units throughout the country during 2016, an event known as National Parks on the Air. Operators
compete for points by activating parks on the air and by making contact with
other parks. The uniqueness of Mr.
Stoetzer’s activation of the National Mall is that it was done entirely
utilizing amateur radio satellites.
Many amateur radio satellites provide two-way communication
capability for operators using simple ground station equipment. The Radio Amateur Satellite Corporation
(AMSAT) partners with universities, The National Aeronautics and Space Administration
(NASA,) and others to launch scientific experiments along with two-way
communications transponders. Paul
Stoetzer, station call letters N8HM, is not only an amateur radio enthusiast
but is very active in the amateur satellite community.
Mr. Stoetzer transported his handheld antenna and two small
transceivers to operate from the National Mall inside a portable camera bag. During two orbits of satellite Fuji OSCAR 29
over Washington, DC, he made contact with twenty-two amateur radio
operators. Contacts were made with
stations from coast-to-coast. Mr.
Stoetzer indicates he would like to activate more National Park service units
around Washington, DC.