Archive for the ‘ham’ Category
Calling Olivia-mode Operators (from All Regions)
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
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.
..
73 de NW7US
..
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!
So, You Want to Get into the Ham Radio Hobby
Come spend some time with me in this ride-along video blog episode, the first in a series that I am doing to help you begin your journey into the amateur radio hobby. This video is an experiment in that I am trying out this format as a type of “chat” in which I share my thoughts and experiences regarding the ham radio hobby, and how you might start out exploring the hobby.
Regarding the experiment: I have tried to edit the sound to reduce the road noise. Please comment on the noise level, and how well you can hear me talking about the topic. Should I ditch the ride-along format? Comments directly on the YouTube channel are better if you leave a comment on the actual video as displayed on my YouTube channel.
..
73 de NW7US
..
What is an Amateur Radio Repeater and How Do They Work?
What is an amateur radio repeater and how do they work?
In this video, with a non-amateur-radio viewer in mind, I chat about the very basic concepts of a repeater. This is a vlog (video blog) entry on my video channel, and it is shot in a relaxed, “ride along with me” format. Feel free to share this short overview with those who might be interested in our hobby. There are more of these sorts of ridealongs coming.
Thank you for watching, and for sharing…
..
ETH075 – RFinder
If you are anything like me you have used those little repeater
directories and strained your eyes in the process. I use to hate trying to find a repeater to use while I was on a trip. Most of the time, while I was on a trip, the town that I was in didn’t have any repeaters in it, but the next town over did. Maybe it was two towns over, or the third of fourth town that I look at in the directory. Either way, it was a pain in the…well you know.
Bob had the same thinking that I did all those years ago, but he acted on it. He went and digitized all the repeater data that was available and made it into an Android app. It is now available to IPhone, Android and on the web for just a small fee.
RFinder is the official repeater directory of Canada, the United Kingdom as well as 13 other countries. This year the ARRL partnered with RFinder to print the 2017 ARRL repeater directory. This years directory has 10,000 more listings and is the first time that the ARRL has crowd sourced the repeater information. The data that RFinder uses comes from many different places including Repeater societies, club websites and directly from repeater owners.
For more information about RFinder, hear it from Bob himself in the latest episode of the Everything Ham Radio Podcast at http://www.everythinghamradio.com/podcast/75
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












