Archive for the ‘hf’ Category
Calling Olivia-mode Operators (from All Regions)
August 13th, 2017 | 
Author: Calling all Olivia-mode operators with experience using the Olivia digital mode in all areas of the world:
Please join our Facebook group at the following link. We are discussing important operational changes!
If you are on Facebook, and interested in the Olivia HF radioteletype chat mode, please join the community group at the following link: https://www.facebook.com/groups/olivia.hf/
If you want to join our discussion by way of the Olivia group on Groups.io, please feel free to spread the news, and also to subscribe to that group email reflector. We’ll start discussions, soon. Here’s the link: https://groups.io/g/Olivia
OLIVIA (Also, Olivia MFSK) is an amateur digital radioteletype mode designed by Pawel Jalocha, SP9VRC, starting in 2003, and in use by 2005. The Olivia-mode goal was to be effective even in poor propagation conditions on the high frequencies (shortwave).
OLIVIA can decode well under noise, propagational fading (QSB), interference (QRM), flutter caused by polar path propagation and even auroral conditions and sporadic-E. Olivia uses a 7-bit ASCII alphabet. There were a handful of amateur digital modes that were derived from Olivia, including RTTYM and PAX.
Outside of amateur radio two-way communication, this mode is utilized during the tests run by the VoA every weekend. See the VoA RadioGram website, VoARadiogram.net, for the schedule.
The Olivia QSO between K4SOL and NW7US using 16/500 mode settings on shortwave, 2017-AUG-06 @1410UTC
The first on-the-air tests were performed by two radio amateurs, Fred OH/DK4ZC and Les VK2DSG on the Europe-Australia path in the 20-meter amateur band. The tests proved that the protocol works well and can allow regular intercontinental radio contacts with as little as one watt RF power. Since 2005 Olivia has become a standard for digital data transfer under white noise, fading and multipath, flutter (polar path) and auroral conditions.
Voluntary channelization
Since Olivia signals can be decoded even when received signals are extremely weak, (signal to noise ratio of -14 dB), signals strong enough to be decoded are sometimes below the noise floor and therefore impossible to search for manually.
As a result, amateur radio operators have voluntarily decided upon channelization for this mode. This channelization allows even imperceptibly weak signals to be properly tuned for reception and decoding. By common convention amateur stations initiate contacts utilizing either the 16/500 or 32/1000 modes and then switch to other modes to continue the conversation. The following table lists the common center frequencies used in the amateur radio bands.
The traditional channels are now under heavy use by newer modes. Thus, this Olivia group is working on refiguring the strategy for continued use and channelization. Please join us for discussion.
https://www.facebook.com/groups/olivia.hf/
[embedyt]https://www.youtube.com/watch?v=g-EXniWF79w[/embedyt]
[embedyt]https://www.youtube.com/watch?v=FUjiBVsXrzE[/embedyt]
[embedyt]https://www.youtube.com/watch?v=Yz7a–ePSNs[/embedyt]
Thank you,
Tomas / NW7US
What a Zoo!
The question I raised in my article about JT65’s success (“Who’s next?”) has already been answered: Joe Taylor. The same guy that brought us the JT mode of families has devised the mode FT-8, developed together with Steven Franke (K9AN). It’s basically turbo charged JT65, with a message length of only 12.64 seconds and transmission beginnings synced to the next 15 second interval. It’s not as sensitive as JT65, but that might change when a priori information is added at a later stage.
My version of WSJT-X was automatically updated to 1.8.0-rc1 on July 11th and just for fun I decided to check out if there was any FT-8 activity. There was: a couple of VKs and JAs. I was a bit surprised, because I had been monitoring FSQ which has been around for a while already and I couldn’t find any activity. FT-8 had only just been introduced so that was a good sign. It got even better when I noted some European stations popping up in the local evening. I tried my hand at making a QSO, but couldn’t get through, so my first ever FT-8 QSO was with HS7WMU from Thailand. The reason why I couldn’t get through became clear later: the delta loop for 6 meters was still hooked up to the rig! After switching to a proper antenna if became apparent that even my modest verticals didn’t have any problem in getting through to Europe. Even better, stations from the east coast of the US were also coming in fine early evening and I also had no problem working them. (Over here in Taiwan the eastern US is one of the more difficult regions of the world to work).
Over the course of the next few weeks I noticed a steady increase in the number of stations I could receive. The statistics page of pskreporter.info backs this up. As I write this the number of FT-8 spots over the last 2 hours outnumber the JT65 spots 2 to 1. JT9 has already been relegated to the margins, so it seems Amateur Radio’s new favourite mode has become FT-8.
I have always been critical of the JT modes, mainly because they reduce QSOs to a 599 exchange with no possibilities to engage in a more meaningful conversation. Plus, JT65 is boringly slow. So, how do I feel about FT-8? Well, it’s not slow at all. In fact, you don’t even have time to push the appropriate macro buttons on the screen, so let WSPR-X do all the work for you. Even answering a reply to your own CQ can be handled automatically, which frees your hands into doing something else (In my case practising guitar. I’m working on Lindsey Buckingham’s “Never Going Back Again“, but don’t expect any performance soon). Arm chair DXing but still no possibility to start a real conversation with the other party. Not great in my book.
Screen capture of WSJT-X with my first ever FT-8 QSO. Notice the checks with “Auto Seq” and “Call 1st”. Keep these on if you want smooth, automatically sequenced QSOs.
Still, I’ve been playing with FT-8 a lot and it is kind of fun. I normally only log some four hundred QSOs a year and in the last two years that has been reduced to forty or less. Honestly, till July 14 I only had 22 QSOs in my log for 2017. Now I’m way over 240 of which 212 are FT-8 QSOs. July 8th was the highlight so far: SSN of 11 and the K index only 1, so pretty good ionospheric conditions. Within 4.5 hours I worked 50 stations from 19 DXCC entities, working from the east coast to the west coast of the US (I added four new states for my WAS), then into Europe. I hardly had any time to put out CQs, because the next station was already calling me before the previous QSO was finished. The pass band on the scope was filled to the brim, when one anonymous ham sent out the cry that became the title of this post: “What a Zoo!”
Screen capture of pskreporter with all the stations I received on August 8 in the span of 4.5 hours.
He may have found it a zoo, but I like zoos, a lot. All joking aside, the one thing that really attracts me to FT-8 is the fact that you can do real time ionospheric observations. WSPR was meant for this, but the number of WSPR stations is too small and signals are too infrequent to be very accurate in my opinion. By constantly monitoring the FT-8 pass band I already noted a couple of sudden ionospheric disturbances and even a complete black out. Sometimes it only takes minutes for conditions to change from favourable to abismal and as a self reliant ham FT-8 is then a nice monitoring tool to have.
So apart from Antenna Summer, this has also become FT-8 Summer. Until the end of August (summer break) I will be active from 05 to 15 UTC most days, calling CQ a lot. I’m on 20 meters only, so if you see me on your waterfall there give me a call.
Hallicrafters Shortwave Radio; Winning WWII With Technology (1944)
Great film about a great radio manufacturer and radio set.
In 1944, this short subject film was produced by the Jam Handy Organization and sponsored by the Hallicrafters Company. It shows the construction of the SCR-299 and dramatizes its use during World War II. This is a B&W documentary presenting a look at the manufacturing and use of the (now defunct) Hallicrafters Company’s SCR-299 “mobile communications unit.” This 1944 film, produced with help from the US Army Signal Corps, and by the Hallicrafters Company, explains how, using radio gear such as this Hallicrafters shortwave radio transmitter and receiver technology, the US Forces and Allies were better equipped to win World War II.
The SCR-299 “mobile communications unit” was developed to provide long-range communications during World War II. The US Military sought improvements of range, flexibility and durability over its existing SCR-197 and SCR-597 transmitters. In 1942, Hallicrafters Standard HT-4 was selected as the SCR-299’s transmitter, known subsequently by its military designation as the BC-610. The SCR-299 was first used on November 8, 1942, during Operation TORCH involving companies of the 829th Signal Service Battalion establishing a radio net that could exchange messages between beach-landed forces and bases in Gibraltar. Despite initial problems unloading the sets from convoy ships, the SCR-299s served until the installation of permanent Army Command and Administrative Network stations. According to US Army military historians, “General Dwight Eisenhower credited the SCR-299 in his successful reorganization of the American forces and final defeat of the Nazis at Kasserine Pass.”
The SCR-299 was a “self-contained” receiving and transmitting mobile high-frequency (HF; or, shortwave) station capable of operating from 2 MHz to 8 MHz. Using conversion kits, it could operate from 1 MHz to 18 MHz. The transmitter output reached 350 watts.
The entire unit came in a K-51 truck except for Power Unit PE-95 which was in a K-52 trailer. Power could either be supplied by the Power Unit and a 12-volt storage battery or 115-volt 60-cycle AC commercial power and two spare 6-volt storage batteries. The power requirement was 2000 watts, plus 1500 watts for heater and lights.
The system could be remotely controlled up to a distance of one mile (1.6 km) using two EE-8 field telephones and W-110-B Wire kit. Remote equipment was provided for remotely keying or voice modulating the transmitter, remotely listening to the receiver, and for communicating with the operator of the station.
Read more details here: http://en.wikipedia.org/wiki/SCR-299
Public domain film from the Library of Congress Prelinger Archive.
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73 de NW7US
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Old, But Still Useful!
This old WWII military training video is still useful regarding Morse code:
[embedyt]https://www.youtube.com/watch?v=YqTn-165orw[/embedyt]
This is an antique United States Navy Training Film from 1943/1944, in which proper hand-sending of Morse code is demonstrated. The film covers some basic principles and mechanics of manual keying of the International Morse code, as used during WWII.
Amateur (Ham) radio operators find Morse code (and the ‘CW’ mode, or ‘Continuous Wave’ keying mode) very useful, even though Morse code is no longer required as part of the licensing process. Morse code is highly effective in weak-signal radio work. And, preppers love Morse code because it is the most efficient way to communicate when there is a major disaster that could wipe out the communications infrastructure.
While this military film is antique, the vintage information is timeless, as the material is applicable to Morse code, even today.
There’s more about Morse code, at my website: http://cw.hfradio.org
For additional joy, here are a few of old films regarding Morse code:
Morse Code – Principles and Basic Techniques (US Army Signal)
(Learn to Send Perfect Morse Code by Hand – Vintage Training Film (Ham Radio / CW))
[embedyt]https://www.youtube.com/watch?v=qmg1MlstxWM[/embedyt]
Vintage 1944 Radio Operator Training: How to Send Morse Code (CW) by Hand
[embedyt]https://www.youtube.com/watch?v=XjupJslRj5E[/embedyt]
This one is a pretty cool film:
1939 Film: New Zealand Shortwave Communications; Morse code (CW)
[embedyt]https://www.youtube.com/watch?v=H-KUat5WEkU[/embedyt]
I’ve also created a play list, and most of the videos are still online. Once and a while something changes and I have to update the list. Here is the list:
Original Title: TECHNIQUE OF HAND SENDING, by Department of Defense, Published 1944
Usage CC0 1.0 Universal
TECHNIQUE OF HAND SENDING
PIN 23735 1944
IMPORTANT PARTS OF THE TRANSMITTER, TENSION SPRING, ADJUSTING CONTACTS, ADJUSTING SPRINGS. ELEMENTS OF MORSE CODE, TIMING, AND PARTS OF BODY THAT FUNCTION WHEN TRANSMITTING CODE. IMPORTANCE OF CORRECT POSITION AND OPERATION.
Producer Department of Defense
Enjoy!
System Fusion DR-2X Repeater, Solar Eclipse and More – ETH079
In this episode we talk about the Yaesu System Fusion DR-2X repeater, the upcoming Solar Eclipse and more.
There is some interesting new features on the DR-2X repeater over the DR-1X that came out a couple years ago, but there is also something that it doesn’t have. Some of these features, I wish that we had on our club repeater, but those features are not enough for us to go out and buy this version.
There are a lot of special event stations that are going to be on the air around August 21st this year when the full solar eclipse occurs. This is the first time since 1918 that a full solar eclipse has gone from one side of the US to the other. I unfortunately am to far south to the see the full eclipse, but I should get about a 75% one here in the DFW area.
We also talk about some other stuff, but you are going to have to check out the show notes and listen to the episode to find out what that is.
73s de Curtis, K5CLM
ETH074 – 13 Colonies Special Event with Bob Josuweit, WA3PZO
It is hard to believe that June is almost over and Independence day will be here in less that ten days! It is time for that long weekend off, where families and friends get together to have a bar-b-que and “party” together. While celebrating the day is good, celebrating the week is even better, and that is exactly what we talk about in this interview.
This special event started back in 2009 and has grown every year since. Operators from each of the original 13 colonies will be on the air from Jul 1 through Jul 7 at different times. You can be part of this special event by making contact with any or all of the 13 colony stations or the two bonus stations.
Check out the show notes and listen to the episode for more information
Arduino Projects for Amateur Radio with Glen Popiel – ETH072
Do you want to get back to the original roots of Amateur Radio? Maybe you are a new ham and you have a DIY side? Maybe you just want to try something new? There are so many things that you can do with an Arduino that cost only $4 or so! Anything from a morse code keyer to a 40m QRP CW Radio and a whole lot in between. You can even do things with an Arduino that has nothing to do with amateur radio but you will find a use for.
In this episode with talk with Glen Popiel, KW5GP the author of the ARRL published books, Arduino for Ham Radio and his new book that just came out, More Arduino for Ham Radio. He is also the author of the ham mesh networking book, High Speed Multimedia for Amateur Radio.
We had a great conversation and it made me literally go to the ARRL website and buy his new Arduino book while we were recording! Check out the show notes of this episode to listen and to get more information about what we talked about. There are also links to his books that you can go to to buy one for yourself.
