Posts Tagged ‘Satellite’
Operating from countries outside the US can be a lot of fun. I just completed another another Slacker DXpedition, this time to the Cayman Islands. The formula for this type of operation is simple: identify an interesting vacation spot that is also considered DX, travel there with friends & family, take along some compact radio gear and get on the air. A key point is to not overdo the radio operating or the friends & family will veto any radio activity on future trips.
Licensing for the Cayman Islands is relatively easy if you hold a US FCC amateur radio license. Complete info can be found on the Ofreq web site. Licensing for the Caymans is typical of many Caribbean countries: fill out the application form, send it to Ofreq by email along with a copy of your US license, passport and $25US. Visitor call signs have the prefix ZF2 and you can request your favorite two-letter suffix. That’s how I got ZF2NR.
I was issued a Class A license which has all operating privileges. My spouse Joyce/K0JJW holds a US General Class license and was issued a Cayman Class B license, which has limited HF privileges (no phone on 40m, 20m, or 17m). So keep that in mind if you have a General Class license.
Grand Cayman is in grid EK-99 and is IOTA NA-016.
My equipment strategy was the same as my V29RW operation on Antigua (see V29RW: Slacker DXpedition to Antigua). The basic kit is a Yaesu FT-991 driving a end-fed halfwave (EFHW) wire antenna for the band of interest. Never underestimate the power of getting a halfwave antenna up into the air. The FT-991 fits in my carry-on bag and it covers all bands from HF through 70cm.
There is a 2m repeater (146.76 MHz) on Grand Cayman that works quite well. We received a friendly welcome on the repeater from Phil ZF1PB and several other Cayman hams.
Our group rented a nice vacation home near Rum Point on the north side of Grand Cayman. This place is right on the water with an excellent sand beach. Denny KB9PDF/ZF2PF and I put up the EFHW 20m antenna supported by my SOTAbeams pole strapped to a palm tree. This setup worked quite well and we soon had a nice pileup of stations calling us on 20m. We did have some issues with local noise sources, the worst of which was traced to some dimmer switches in the house. This is one of the problems with a portable setup like this…you never know what RFI problems you’ll encounter. Later in the week, we put up a 40m EFHW and made a few contacts on that band, too.
Bruce/K0BJ suggested that I check into using the Cayman Amateur Radio Society club station (ZF1A) which they make available to visiting hams. I connected with Eden/ZF1EJ who confirmed that the station was available later in the week. Again, I did not want to overdo the radio thing, so we settled on operating at ZF1A during the middle of the day on Wednesday.
This turned out to be a great move. ZF1A has multiple towers with some very capable antennas. Like I always say: Never underestimate the power of using a large directional antenna on top of a big tower. Eden/ZF1EJ met us at the station (it is literally in his backyard) and helped us get situated. Our operating strategy was simple: use the highest HF phone band that had good propagation and work as many stations as possible. We were also prepared to use FT8 if things were really bad but that was not needed. It turned out that 15m was dead but 17m was open into North America and Europe, so we did most of our operating there.
Here’s a short video to give you a taste of the pileup.
I did work some of the folks back home, which was a treat: K0AV, W0CP, K0BJ, W0RLY, W0GAS, WG0AT, KD0RQU. I had noticed that Steve/WG0AT was doing a Summits On The Air (SOTA) activation on Crooked Top Mountain (W0C/SP-090) and I gave him a call. Being QRP, his signal was very weak at my location but he could hear me with no problem.
Here’s the QSO audio that Steve recorded on his end:
We worked two OSCAR satellite passes (AO-91, AO-92) using a pair of handheld radios and an Arrow 2m/70cm yagi antenna. The pair of handhelds gave us full-duplex capability: I ran the 70cm uplink on my HT while Denny ran the downlink on 2m. No surprise to find the FM satellites quite busy and a bit frustrating to work. I logged these stations from ZF2NR: KI0G, K3SV, TI2CDA, TI4DJ, HP2VX.
My ZF2NR log shows 376 HF QSOs, most of them made by me. Joyce K0JJW/ZF2JW braved the pileup to make a few contacts. Denny/KB9DPF had some additional contacts as ZF2PF. QSL to our home callsigns.
I’ve loaded the ZF2NR log into Logbook of The World.
Band Mode QSOs 7 LSB 5 14 USB 65 18 USB 306 Total 376
In retrospect, I realized that we had the antenna pointed north most of the time and we probably should have looked in other directions. In particular, we only worked a few South American stations.
Most important is that a good time was had by all. Thanks to everyone that worked us while we were in the Cayman Islands.
73, Bob K0NR/ZF2NR
As you know, we are entering a period which could last very many years when the higher HF bands will not be good for F layer DX. OK, we will have Es to liven things up, but much of the time bands like 10m will seem “dead”.
To the rescue (if successful and this is a big “if”) could come amateur geosynchronous satellites using linear transponders at microwaves. One such is a Qatar satellite that may be launched next year. I say “maybe” as the launch has already been delayed. Geosynchronous satellites stay in the same place, so antennas can be fixed.
A 2.4GHz uplink and 10GHz downlink is quite an investment, but could be worth it if the satellite is a success.
In this episode, Linux in the Ham Shack discusses diverse topics including 915MHz operation, a new cube satellite, "smart" ham radio, a new Ubuntu distro with Budgie as the default desktop, games, ssh honeypots, a PHP-based logger and much more. Thanks for listening and all the best. Happy holiday season to all.
73 de The LHS Crew
Congratulations to AMSAT for the successful launch and initial deployment of the Fox-1A amateur radio satellite.This bird has been designated AO-85 and has an FM transponder on board (435.180 MHz uplink, 145.980 MHz downlink).
I have not heard or worked this satellite yet but early reports indicate that it has a strong signal on the downlink. So start out by trying to hear the bird on 145.980 MHz. To find out when it will be overhead, use the AMSAT pass prediction page or your favorite satellite tracking software.
Download the Special Issue of the AMSAT Journal to get the full story.
73, Bob K0NR
It is about time I updated one of my more popular posts about my favorite ham radio apps on the iPhone and IPad. As usual, I will focus on free or low cost (less than $5) apps that I am actively using. Some apps have just disappeared from iTunes and new ones have emerged. While this list is completely updated, it is still incomplete, because there are so many apps to choose from.
From the Simple Utility Category:
Ham I Am (Author: Storke Brothers, Cost: Free) A handy app that covers some basic amateur radio reference material (Phonetic alphabet, Q Signals, Ham Jargon, Morse Code, RST System, etc.) Although I find the name to be silly, I like the app!
Maidenhead Converter (Author: Donald Hays, Cost: Free) Handy app that displays your grid locator, uses maps and does lat/lon to grid locator conversions.
HamClock (Author: Ben Sinclair, Cost: $0.99) A simple app that displays UTC time and local time. This one reads out to the second.
There are quite a few good apps for looking up amateur radio callsigns:
CallBook (Author: Dog Park Software, Cost: $1.99) Simple ham radio callbook lookup with map display.
Call Sign Lookup (Author: Technivations, Cost: $0.99) Another simple ham radio callsign lookup with map display.
There are a few repeater directory apps out there and my favorite is:
RepeaterBook (Author: ZBM2 Software, Cost: Free) This app is tied to the RepeaterBook.com web site, works well and is usually up to date.
For a mobile logbook (and other tools):
HamLog (Author: Pignology, Cost: $0.99) This app is much more than a logbook because it has a bunch of handy tools including UTC Clock, Callsign Lookup, Prefix list, Band Plans, Grid Calculator, Solar Data, SOTA Watch, Q Signals and much more.
To track propagation reports, both HF and VHF:
WaveGuide (Author: Rockwell Schrock, Cost: $2.99) This is an excellent tool for determining HF and VHF propagation conditions at the touch of a finger.
If you are an EchoLink user, then you’ll want this app:
EchoLink (Author: Synergenics, Cost: Free) The EchoLink app for the iPhone.
There are quite a few APRS apps out there. I tend to use this one because my needs are pretty simple….just track me, baby!
Ham Tracker (Author: Kram, Cost: $2.99) APRS app, works well, uses external maps such as Google and aprs.fi. “Share” feature allows you to send an SMS or email with your location information.
Satellite tracking is another useful app for a smartphone:
Space Station Lite (Author: Craig Vosburgh, Cost: Free) A free satellite tracking app for just the International Space Station. It has annoying ads but its free.
ProSat Satellite Tracker (Author: Craig Vosburgh, Cost: $9.99) This app is by the same author as ISS Lite, but is the full-featured “pro” version. Although it is a pricey compared to other apps, I recommend it.
For Summits On The Air (SOTA) activity, there are a few apps:
Pocket SOTA (Author: Pignology, Cost: $0.99) A good app for finding SOTA summits, checking spots and accessing other information.
SOTA Goat (Author: Rockwell Schrock, Cost: $4.99) This is a great app for SOTA activity. It works better when offline than Pocket SOTA (which often happens when you are activating a summit).
For ham radio license training, I like the HamRadioSchool.com apps. (OK, I am biased here as I contribute to that web site.)
HamRadioSchool Technician (Author: Peak Programming, Cost: $2.99) There are a lot of Technician practice exams out there but this is the best one, especially if you use the HamRadioSchool.com license book.
Morse Code is always a fun area for software apps:
Morse-It (Author: Francis Bonnin, Cost: $0.99) This app decodes and sends Morse audio. There are fancier apps out there but this one does a lot for $1.
Well, that’s my list. Any other suggestions?
– Bob K0NR
The post The Completely Updated Incomplete List of Ham Radio iPhone Apps appeared first on The KØNR Radio Site.
Retired from Qualcomm, Karn seems to be staying busy with other interesting projects — like this one.
Filed under: Ham Radio Tagged: amsat, ka9q, satellite, space, video
As I mentioned in passing yesterday I have a number of Arduino based projects buzzing around in my head. One of them is to produce a satellite antenna pointer/indicator.
I have used an Android AR tracking solution before (flaky at best) and can see the relevant information in Orbitron or SatPC32 to know where to point the antenna but it is difficult to see a PC screen when stuck out in the middle of the lawn!
My idea is this, I will make a large tripod to which I can attach appropriate antenna as I need, then during the satellite pass it has indicators to show where to point the antenna manually.
I envisage the azimuth indicator to be a large horizontal circle with 36 LEDs positioned at 10 degree intervals, the elevation will be a quarter circle with 20 LEDs positioned at 5 degree intervals. Then during the pass the appropriate LEDs will light and assuming I keep the antenna aligned to these I should in theory get the best signal... Crazy??
Yes I know I could make or buy an azimuth/elevation rotator, eBay is full of low speed high torque geared DC motors with auto-stop/hold and numerous software solutions exist to drive them but this would require a bit more engineering and isn't something I can easily fabricate at the moment. My contraption would be much more rustic being made of rough cut timber!
Bright LEDs are ridiculously cheap and controlling this number from the Arduino will require the use of multiplexer drivers. The popular ones are the MAX 7219/7221
I won't go into the details of exactly what multiplexing is, other than to say that each display element (LED) is driven one at a time but by switching the electronics at high speed combined with the persistence of vision make the viewer believe the entire display is continuously active.
This technique can be used for individual LEDs, an LED grid matrix, or for 7 segment displays. Last night I successfully got a MAX7219 based 8-Digit 7-Segment LED module working.
The next stage was to investigate how an Arduino could calculate the appropriate azimuth and elevation data. Thankfully a library already exists qrpTracker (code is here), within this library is a port of the Plan-13 algorithm first written in Basic by James Miller G3RUH in 1990, subsequently ported to C by Edson Pereira, N1VTN and further updated by Howard Long, G6LVB.
Plan-13 processes keplerian elements, time and (optionally) observer location, and uplink downlink frequencies; it outputs satellite latitude and longitude, azimuth and elevation, and Doppler shifted frequencies. At the standard 16 MHz Arduino clock speed, this code can complete these calculations in approximately 30 ms. This code is reported to be highly accurate, if provided with proper data.
The important data are the observer location (longitude/latitude) and the current time. Step forward my well used GPS module which once lock is achieved can supply that data.
The next is get the appropriate up to date Keplerian twin element sets (TLE) and extract the appropriate information from it and pass that data to the Plan-13 functions.
The standard TLE follows the following format
You need to extract the Epoch Year/Day (including partial data), Inclination, Right Ascension, Eccentricity, Perigee, Mean anomaly and Mean Motion for a calculation (drag/orientation aren't critical) For the moment I have just extracted this manually from the latest TLE and entered it directly into the program.
After just an hour or so of research and programming I have the LED displaying the current azimuth and elevation of the FUNCube-1 satellite (AO73) based on the current position and time derived from the GPS!
The first four digits is the azimuth, the second four the elevation.