Posts Tagged ‘Digital’
Short Demonstration of Using Ham Radio Deluxe with WSJT-X and FT8 Digital Mode
April 1st, 2018 | 
Author: Ham Radio Deluxe can log your WSJT-X FT8, JT65A, and JT9 QSOs, via the JT-Alert software. This is a demonstration of my use of HRD and Logbook, during an FT8 QSO,today.
As some of you know, I have had some differences of opinion regarding the selection of frequencies chosen by the FT8 creators and advocates. Regardless, I do still use the mode. Here is proof:
Go ahead and share, if you would. And, please subscribe to my YouTube channel, as I will be creating many how-to videos in the near future.
Thanks and 73 … de NW7US
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
Digital Revolution Or Evolution?
 |
| courtesy: KD0WTE |
A recent reflector posting tended to confirm a rather intriguing trend that I have also been noticing over the past few years.
The poster lamented the fact that he often found very few or even no CW / SSB signals on the HF bands while at the same time seeing lots of activity throughout the digital portion of the bands.
It does seem like there is far less CW and phone activity on the HF bands now, than there was a few years ago and there is no question that digital activity has soared. Whether it's RTTY, PSK31, JT65, WSPR, JT9 or others, these digital signals are always prominent and, band plan or not, are slowly migrating further in the band as activity increases ... but is this the reason for the decline of traditional modes?
The digital weak-signal modes make these extremely popular for a number of reasons. Nowadays, many amateurs are living in antenna-restricted communities and are forced to develop smaller, lower and less effective stealthy antenna systems if they wish to get on the air and make contacts. Most of these modes perform well with minimal amounts of power and are capable of hearing well into the noise ... and unless you live out in the country, with well-separated neighbours, we all know that noise is increasing at horrific levels almost everywhere. These two factors alone might well explain much of the growth in digital activity.
Licencing requirements have also been slowly evolving and today, getting a ticket is much easier than it was several decades ago ... and in many cases, without the requirements of knowing anything about CW. Every month, North Americans see a large number of new amateurs, many with no code skills and possibly not much interest in acquiring them. From my own local observations, most of these new amateurs usually head straight to FM on the VHF/UHF bands and have little knowledge of or interest in HF radio. These factors must also play into the demise of activity on the traditional HF modes as well.
We also shouldn't overlook the influence that Old Sol is having on our HF bands as well. Solar Cycle 24 (begun in 2008) has been one of the poorest on record and continues to generate month after month of terribly poor HF propagation. As a young SWL who listened in Cycle 19, (the largest on record), I can vouch for the relationship between HF activity and good propagation. Those were amazing days, when 20 and 15m would stay open all night long ... even 10m would often still be open with F2 propagation at midnight towards VK and ZL! Everyday, month after month, the bands were simply bulging with activity, from end to end ... high solar flux numbers bring high activity numbers and we are now experiencing the downside effects of what happens when the sun dreadfully underperforms. The only exception to band-bulging activity today seems to be limited to major contest weekends only. Where these people go the rest of the time is a mystery.
There are surely other reasons as well for the gradual decline of traditional-mode HF activity, including the fact that the general ham population is getting older. Large numbers of stations are simply 'going away' as interest or opportunity declines and as more of the aging traditional-mode ops go 'SK'. I know of several hams that have just given-up because of insurmountable increases in their local noise floors. Our new and usually younger hams, have largely grown up in the 'digital age' and for those that do find themselves exploring the HF bands without CW skills, might logically settle into the digital modes first.
Things are changing quickly, of that there is no doubt. Last summer, on 50mHz, I noticed a large increase in the number of dedicated CW operators moving to JT65 and JT9 during openings and this summer has already seen another huge migration from one mode to the other.
Although this year's Sporadic-E season is just getting started, I have already heard many more countries on JT65 than I have on the traditional modes (Japan, Philippines, China, Formosa, Alaska, Venezuela, Cuba, Brazil). Yesterday I listened to a PY calling CQ on CW for some length, with no takers, while it seemed most of the usual west coast ops were watching the digital band. I fear that many good QSO possibilities will be lost as more stations switch to the much slower digital modes ... on 6m, many of the openings last for a very short time making CW or SSB the quickest way to complete a contact. The other problem I notice this summer is that there are several JT sub-modes and it is often difficult or impossible to figure out which mode is being used let alone having the time to switch to the other mode before signals are gone ... perhaps a case of having too much of a 'good thing'? Hopefully one mode will emerge as the '6m standard' so all are on the same page.
What will be the long-term outcome of these changes remains to be seen but I suspect we'll see more and more of our HF CW and SSB spectrum space gradually shrinking to make room for more digital activity, likely to become the dominant modes eventually.
As a life-time, almost exclusive CW operator since age 15, I find this somewhat disheartening but must admit that over the past few years, I have found my own level of weak-signal digital activity increasing by leaps and bounds. These are powerful, capable modes and offer amateurs new and exciting challenges from VLF to nanowaves. Are they as exciting as my much-loved CW? Ask me in a couple of years!
Digital Revolution Or Evolution?
|
| courtesy: KD0WTE |
A recent reflector posting tended to confirm a rather intriguing trend that I have also been noticing over the past few years.
The poster lamented the fact that he often found very few or even no CW / SSB signals on the HF bands while at the same time seeing lots of activity throughout the digital portion of the bands.
It does seem like there is far less CW and phone activity on the HF bands now, than there was a few years ago and there is no question that digital activity has soared. Whether it's RTTY, PSK31, JT65, WSPR, JT9 or others, these digital signals are always prominent and, band plan or not, are slowly migrating further in the band as activity increases ... but is this the reason for the decline of traditional modes?
The digital weak-signal modes make these extremely popular for a number of reasons. Nowadays, many amateurs are living in antenna-restricted communities and are forced to develop smaller, lower and less effective stealthy antenna systems if they wish to get on the air and make contacts. Most of these modes perform well with minimal amounts of power and are capable of hearing well into the noise ... and unless you live out in the country, with well-separated neighbours, we all know that noise is increasing at horrific levels almost everywhere. These two factors alone might well explain much of the growth in digital activity.
Licencing requirements have also been slowly evolving and today, getting a ticket is much easier than it was several decades ago ... and in many cases, without the requirements of knowing anything about CW. Every month, North Americans see a large number of new amateurs, many with no code skills and possibly not much interest in acquiring them. From my own local observations, most of these new amateurs usually head straight to FM on the VHF/UHF bands and have little knowledge of or interest in HF radio. These factors must also play into the demise of activity on the traditional HF modes as well.
We also shouldn't overlook the influence that Old Sol is having on our HF bands as well. Solar Cycle 24 (begun in 2008) has been one of the poorest on record and continues to generate month after month of terribly poor HF propagation. As a young SWL who listened in Cycle 19, (the largest on record), I can vouch for the relationship between HF activity and good propagation. Those were amazing days, when 20 and 15m would stay open all night long ... even 10m would often still be open with F2 propagation at midnight towards VK and ZL! Everyday, month after month, the bands were simply bulging with activity, from end to end ... high solar flux numbers bring high activity numbers and we are now experiencing the downside effects of what happens when the sun dreadfully underperforms. The only exception to band-bulging activity today seems to be limited to major contest weekends only. Where these people go the rest of the time is a mystery.
There are surely other reasons as well for the gradual decline of traditional-mode HF activity, including the fact that the general ham population is getting older. Large numbers of stations are simply 'going away' as interest or opportunity declines and as more of the aging traditional-mode ops go 'SK'. I know of several hams that have just given-up because of insurmountable increases in their local noise floors. Our new and usually younger hams, have largely grown up in the 'digital age' and for those that do find themselves exploring the HF bands without CW skills, might logically settle into the digital modes first.
Things are changing quickly, of that there is no doubt. Last summer, on 50MHz, I noticed a large increase in the number of dedicated CW operators moving to JT65 and JT9 during openings and this summer has already seen another huge migration from one mode to the other.
Although this year's Sporadic-E season is just getting started, I have already heard many more countries on JT65 than I have on the traditional modes (Japan, Philippines, China, Formosa, Alaska, Venezuela, Cuba, Brazil). Yesterday I listened to a PY calling CQ on CW for some length, with no takers, while it seemed most of the usual west coast ops were watching the digital band. I fear that many good QSO possibilities will be lost as more stations switch to the much slower digital modes ... on 6m, many of the openings last for a very short time making CW or SSB the quickest way to complete a contact. The other problem I notice this summer is that there are several JT sub-modes and it is often difficult or impossible to figure out which mode is being used let alone having the time to switch to the other mode before signals are gone ... perhaps a case of having too much of a 'good thing'? Hopefully one mode will emerge as the '6m standard' so all are on the same page.
What will be the long-term outcome of these changes remains to be seen but I suspect we'll see more and more of our HF CW and SSB spectrum space gradually shrinking to make room for more digital activity, likely to become the dominant modes eventually.
As a life-time, almost exclusive CW operator since age 15, I find this somewhat disheartening but must admit that over the past few years, I have found my own level of weak-signal digital activity increasing by leaps and bounds. These are powerful, capable modes and offer amateurs new and exciting challenges from VLF to nanowaves. Are they as exciting as my much-loved CW? Ask me in a couple of years!
LHS Episode #159: Digital Mode Interfaces
Hello, dear listeners! Thank you for tuning into another episode of Linux in the Ham Shack. In this week's episode, your hosts discuss a variety of topics from 600-meter operation to Linux in cars to Star Wars. Our featured segment tonight is a look at PC-to-radio interfaces for digital mode communication. Thanks for tuning into, and hope to see you next time.
73 de The LHS Team
What is the big deal with amateur radio? What is it that you hear? (Part 1)
Shortwave radio has been a source for great sci-fi plots, spy intrigue novels, movies, and so on, since radio first became a “thing.” But, what is the big deal, really? What is it that amateur radio operators listen to?
In this video, I share some of the types of signals one might hear on the high frequencies (also known as shortwave or HF bands). This is the first video in an on-going series introducing amateur radio to the interested hobbyist, prepper, and informed citizen.
I often am asked by preppers, makers, and other hobbyists, who’ve not yet been introduced to the world of amateur radio and shortwave radio: “Just what do you amateur radio operators hear, on the amateur radio shortwave bands?”
To begin answering that question, I’ve taken a few moments on video, to share from my perspective, a bit about this shortwave radio thing:
Link to video: https://youtu.be/pIVesUzNP2U — please share with your non-ham friends.
From my shortwave website:
Shortwave Radio Listening — listen to the World on a radio, wherever you might be. Shortwave Radio is similar to the local AM Broadcast Band on Mediumwave (MW) that you can hear on a regular “AM Radio” receiver, except that shortwave signals travel globally, depending on the time of day, time of year, and space weather conditions.
The International Shortwave Broadcasters transmit their signals in various bands of shortwave radio spectrum, found in the 2.3 MHz to 30.0 MHz range. You might think that you need expensive equipment to receive these international broadcasts, but you don’t! Unlike new Satellite services, Shortwave Radio (which has been around since the beginning of the radio era) can work anywhere with very affordable radio equipment. All that you need to hear these signals from around the World is a radio which can receive frequencies in the shortwave bands. Such radios can be very affordable. Of course, you get what you pay for; if you find that this hobby sparks your interest, you might consider more advanced radio equipment. But you would be surprised by how much you can hear with entry-level shortwave receivers. (You’ll see some of these radios on this page).
You do not need a special antenna, though the better the antenna used, the better you can hear weaker stations. You can use the telescopic antenna found on many of the portable shortwave radios now available. However, for reception of more exotic international broadcasts, you should attach a length of wire to your radio’s antenna or antenna jack.
LHS Episode #149: Coming Up Lemons
Hello again, and welcome to Episode #149 of Linux in the Ham Shack. In this episode we tackle a number of interesting and diverse topics: Starting with Field Day and an online course on Climate Change, we move to software patent legislation, deep topics like buildroot and custom Linux images, and then to hardware reverse engineering for your benefit and a utility for helping you save battery power on your laptop. We even manage to get in an interview with our ambassador to SELF, Darrell, KI4LLA. Don't miss one action-packed second.
73 de The LHS Guys
