Saturday, April 16, 2016

April 11-14 2016 ISS SSTV Images Received

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

12-April 21:32 UTC

12-April 21:38 UTC

12-April 2309 UTC

12-April 23:15 UTC

13-April 00:51 UTC

13-April 02:25 UTC

13-April 02:30 UTC

13-April 04:03 UTC

13-April 04:09 UTC

13-April 05:38 UTC

13-April 05:42 UTC

13-April 20:39 UTC

13-April 20:46 UTC

13-April 22:16 UTC

13-April 22:21 UTC

13-April 23:56 UTC

14-April 01:33 UTC

14-April 01:39 UTC

14-April 03:08 UTC

14-April 03:12 UTC

14-April 03:18 UTC

14-April 04:45 UTC

14-April 04:51 UTC

Second Series of Images for the MAI-75 Event

15-April 17:23 UTC

15-April 18:53 UTC

15-April 18:59 UTC



Wednesday, April 13, 2016

A Tale of Two Antennas: What you can do in ideal locations with a handheld yagi

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:

Stations:
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.


Location, location, location.  

Friday, April 1, 2016

Satellite EO-79 (QB50p1 and FUNcube-3) - March 25, 2016

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.

Read more about EO-79 here http://www.amsat.org/?page_id=2944 on the AMSAT website.


Tuesday, March 29, 2016

Satellite radios: Don't lock those VFO's on LEO's (satellites)

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)



Final thoughts:

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.

Monday, March 28, 2016

Paul Stoetzer, N8HM, Operates Amateur Radio Satellites from the National Mall in Washington, DC

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.

For details on the ARRL National Parks on the Air program, visit http://www.arrl.org/npota.  To learn more about amateur satellites, the AMSAT website at http://www.amsat.org

Listen to Paul making contact with a few stations on SoundCloud:



Saturday, February 27, 2016

More fun with the Short Arrow

This week, I decided I'd try out some new LMR-240uf jumpers that had arrived. Most of the jumpers I use in my portable station are 10', either the LMR-240 (stiffer/solid center) or the LMR-240uf (UltraFlex, stranded center.)

For a few years I've really loved the stiffer LMR-240 and it's never been a problem.  However, at a friend's insistence I went ahead and made some LMR-240uf jumpers.  I've yet to notice a big difference however, I'd probably use the solid center if I was making some record-breaking attempt.


Since there was a LilacSat-2 pass rising, I decided to test the jumpers on that pass from my patio, facing east.  Here's the catch: I wanted to use a single Yaesu FT-817.  Yes, it would be semi or "half" duplex (not my favorite/recommended,) but it was a good chance to test both jumpers.  Before I used them on RF, I did do a quick continuity check with my VOM to make sure the cables had no short.

How can I test both jumpers on the FT-817 without using the Arrow diplexer you ask?

The FT-817 has two antenna ports.  Simply configure UHF for one port and VHF for the other.  You do this by going to the band and selecting the antenna in your menu: Front or Rear.

Since both jumpers are terminated with BNC males, I did need to use an adapter on the FT-817's rear SO-239.  It's not my recommendation to use adapters since they are prone to failure and can sometimes be lossy (especially cheap ones.)  


 
All in all, it was a quick and easy test.  I made 3 contacts on this pass: Tennessee, Ohio, and Colorado.

Wednesday, February 17, 2016

Recent AO-85 Observations - 17 February 2016 AMSAT-BB Post

For the past several days, I have observed the following:

- On ascending passes, I can activate the transponder at AOS very easily.  Either polarity V or H works.

- Previously, I needed 10-15 degrees at times on ascending passes to activate the transponder.  As I approached TCA, the challenge getting in always went away and I could get into the transponder easily.

- Descending passes have never been an issue for me. I could access the transponder at AOS and activate the transponder as low as 0.1 degrees elevation.

- Downlink receive polarity seems to flip almost constantly or be equal at times.  I'm running a V or H antenna configuration (not RHCP or LHCP.)

- Suspected reason is the spacecraft's spin rate has changed with it now in constant sun.

- As a result I'm hearing some newer stations working AO-85 with handheld transceivers.  I've worked 2 new stations in the last 2 days who emailed me directly after the pass stating they were seeing some success with an HT.