Archive for the ‘qrp’ Category
QRSS experiments: FSKCW and Slow Hell
These last few days I’ve been experimenting with my QRPLabs Ultimate 2 and Ultimate 3s transmitting on 7 MHz. In addition to WSPR, the modes transmitted have been FSKCW with 6 second long dots, and Slow Hell with 17 second long characters. The result as received this morning can be seen on the display from the grabber of Les, G3VYZ in Northumberland, UK. This is a stack of 6 consecutive 10 second frames as can be found on the QRSS grabber site of AJ4VD.
FSKCW and Slow Hell reception of LA3ZA at G3VYZ |
My signal is on 7,039.870 kHz and has been set up with a FSK shift of 6 Hz. Power output was 0.2 W and the distance is about 890 km.
It works but the reception is much less reliable than for WSPR, which is not so unexpected. At the same time the WSPR signal was received all around Northern Europe (G, GM, DL, OON, OE, LX, LA, OY, OH, PA, SM) as well as on the Canary Islands, 3930 km away.
Update: More on Olivia, the Great Compromise Mode
Some HF digital modes were designed for long-distance (DX) radio-wave propagation via the ionosphere. One such keyboard-to-keyboard digital mode is Olivia.
Friday evening, 8 December 2017, at 0200 UTC {9-DEC}, Larry, N7ZDR, called an Olivia-mode 80-Meter digital roundtable net. The following video is a snapshot of about nine minutes of on-air net operations as received at my location in Omaha, Nebraska. My antenna is a wire run from an SEA marine autotuner mounted under the three-story-high roof’s eaves. I live in a high-RF environment within two miles of eight high-powered broadcast antenna facilities–TV, FM, AM–as well as business and public-service transmitters. All that RF desensitizes my receiver. The noise floor is also affected by industrial-level man-made RF noise.
No, Olivia is not lightening-fast keyboard-to-keyboard chatting, but it can get the job done. This following video shows some real-world operation in which the very weakest signals did not decode well. However, even with the 80-Meter band (center frequency is 3585 kHz) really difficult to work with, it did well in terms of what was available for the Ham Radio Deluxe DM780 software to decode.
Example QSO in Olivia Video:
In 2005, SP9VRC, Pawel Jalocha, released to the world a mode that he developed starting in 2003 to overcome difficult radio signal propagation conditions on the shortwave (high-frequency, or HF) bands. By difficult, we are talking significant phase distortions and low signal-to-noise ratios (SNR) plus multipath propagation effects. The Olivia-modulated radio signals are decoded even when it is ten to fourteen dB below the noise floor. That means that Olivia is decoded when the amplitude of the noise is slightly over three times that of the digital signal!
Olivia decodes well under other conditions that are a complex mix of atmospheric noise, signal fading (QSB), interference (QRM), polar flutter caused by a radio signal traversing a polar path. Olivia is even capable when the signal is affected by auroral conditions (including the Sporadic-E Auroral Mode, where signals are refracted off of the highly-energized E-region in which the Aurora is active).
Currently, the only other digital modes that match or exceed Olivia in their sensitivity are some of the modes designed by Joe Taylor as implemented in the WSJT programs, including FT8, JT65A, and JT65-HF–each of which are certainly limited in usage and definitely not able to provide true conversation capabilities. Olivia is useful for emergency communications, unlike JT65A or the newly popular FT8. One other mode is better than Olivia for keyboard-to-keyboard comms under difficult conditions: MT63. Yet, Olivia is a good compromise that delivers a lot.
Join us — not just on the HF waterfall, but by joining our email-based group at:
or, on Facebook at:
–> https://www.facebook.com/groups/olivia.hf
Thanks for spreading the Olivia love! See you on the waterfall.
Addendum:
Current CENTER Frequencies With 8/250 (eight tones, 250-Hz bandwidth):
1.8269 MHz
3.5729 MHz
7.0729 MHz
10.1429 MHz
14.0729 MHz
18.1029 MHz
21.0729 MHz
24.9229 MHz
28.1229 MHz
See the pattern?
The current suggested CENTER frequency with 16/1000 or 32/1000 on 20 meters is 14.1059.
(Why the xxx…9 frequencies? Experts say that ending in a non-zero odd number is easier to remember!)
Q: What’s a ‘CENTER’ Frequency? Is That Where I Set My Radio’s Dial?
For those new to waterfalls: the CENTER frequency is the CENTER of the cursor shown by common software. The cursor is what you use to set the transceiver’s frequency on the waterfall. If your software’s waterfall shows the frequency, then you simply place the cursor so that its center is right on the center frequency listed, above. If your software is set to show OFFSET, then you might, for example, set your radio’s dial frequency to 14.0714, and place the center of your waterfall cursor to 1500 (1500 Hz). That would translate to the 14.0729 CENTER frequency.
The standard Olivia formats (shown as the number of tones/bandwidth in Hz) are 8/250, 8/500, 16/500, 8/1000, 16/1000, and 32/1000. Some even use 16/2000 for series emergency communication. The most commonly-used formats are 16/500, 8/500, and 8/250. However, the 32/1000 and 16/1000 configurations are popular in some areas of the world (Europe) and on certain bands.
These different choices in bandwidth and tone settings can cause some confusion and problems–so many formats and so many other digital modes can make it difficult to figure out which mode you are seeing and hearing. After getting used to the sound and look of Olivia in the waterfall, though, it becomes easier to identify the format when you encounter it. To aid in your detection of what mode is being used, there is a feature of many digital-mode software implementation suites: the RSID. The next video, below, is a demonstration on how to set the Reed-Solomon Identification (RSID) feature in Ham Radio Deluxe’s Digital Master 780 module (HRD DM780).
I encourage ALL operators, using any digital mode such as Olivia, to TURN ON the RSID feature as shown in this example. In Fldigi, the RSID is the TXID and RXID; make sure to Check (turn on) each, the TXID and RXID.
Please, make sure you are using the RSID (Reed Solomon Identification – RSID or TXID, RXID) option in your software. RSID transmits a short burst at the start of your transmission which identifies the mode you are using. When it does that, those amateur radio operators also using RSID while listening will be alerted by their software that you are transmitting in the specific mode (Olivia, hopefully), the settings (like 8/250), and where on the waterfall your transmission is located. This might be a popup window and/or text on the receive text panel. When the operator clicks on that, the software moves the waterfall cursor right on top of the signal and changes the mode in the software. This will help you make more contacts!
RSID Setting:
+ NOTE 1: The MixW software doesn’t have RSID features. Request it!
+ NOTE 2: A problem exists in the current paid version of HRD’s DM780: the DM780 RSID popup box that lists the frequency, mode, and configuration with a link to click, does not work. HRD support is aware of the problem. You can still use the textual version that shows up in the DECODED TEXT window, a feature of RSID that you can select in the HRD DM780 program settings. This setting ensures that the detected RSID details appear in the receive text area. If you click the RSID link that comes across the text area, DM780 will tune to the reported signal, and change to the correct settings.
Voluntary Olivia Channelization
Since Olivia signals can be decoded even when received signals are extremely weak, (signal to noise ratio of -14db), 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 8/250, 16/500, or 32/1000 configuration of the Olivia mode. After negotiating the initial exchange, sometimes one of the operators will suggest switching to other configurations to continue the conversation at more reliable settings, or faster when conditions allow. The following table lists the common center frequencies used in the amateur radio bands.
Olivia (CENTER) Frequencies (kHz) for Calling, Initiating QSOs
It is often best to get on standard calling frequencies with this mode because you can miss a lot of weak signals if you don’t. However, with Olivia activity on the rise AND all the other modes vying for space, a good deal of the time you can operate wherever you can find a clear spot–as close as you can to a standard calling frequency.
Note: some websites publish frequencies in this band, that are right on top of weak-signal JT65, JT9, and FT8 segments. DO NOT QRM weak-signal QSOs!
We (active Olivia community members) suggest 8/250 as the starting settings when calling CQ on the USB frequencies designated as ‘Calling Frequencies.’ A Calling Frequency is a center frequency on which you initially call, ‘CQ CQ CQ. . .’ and then, with the agreement of the answering operator, move to a new nearby frequency, changing the number of tones and bandwidth at your discretion. Even though 8/250 is slow, the CQ call is short. But, it is narrow, to allow room for other QSOs nearby. It is also one of the best possible Olivia configurations for weak-signal decoding.
– End of Addendum –
73
uBITX now on back order.
Demand has just outstripped supply, by what the thinking was there was enough stock to last for 2 months?
Anyone ordering the uBITX now, will not get shipped until after at least the 25th December. This is now being flagged up when you come to order.
Did the uBITX become more successful overnight than the ICOM IC-7300, did it sell more in it's first days of sale? Or does it say to the main three radio manufacturers, you missed a market for a plain no bells and whistles multiband radio that everyone can afford and muck into and understand?
One thing for certain Asharr Farhan has proved without a doubt that he has been the first to achieve and do this, putting into mass production a multiband rig at a price point that everyone can be part of and enjoy! I am sure as well as the uBITX there is a lot more to come from HF Signals in the future!
Well done VU2ESE!
Come Join the Fun With Olivia on HF (Shortwave Digital Mode Olivia)
For those of you who have dived into the crowded but fun pool of FT8 operation or one of the other Joe Taylor modes (such as JT65 or JT9) and are excited now about digital modes, here’s something you might enjoy, too. Unlike those modes that allow you to make quick work of getting DX stations into your logbook, simply by exchanging callsigns, a signal report, and a grid square, there are other modes that offer keyboard-to-keyboard conversational QSO opportunities.
One such mode is known as Olivia and this mode offers keyboard-to-keyboard chatting for when you want to relax, and maybe make a friend. Ham radio is the oldest electronic social networking infrastructure.
In 2005, SP9VRC, Pawel Jalocha, released to the world a mode that he developed starting in 2003 to overcome difficult radio signal propagation conditions on the shortwave (high-frequency, or HF) bands. By difficult, we are talking significant phase distortions and low signal-to-noise ratios (SNR) plus multipath propagation effects. The Olivia-modulated radio signals are decoded even when it is ten to fourteen dB below the noise floor. That means that Olivia is decoded when the amplitude of the noise is slightly over three times that of the digital signal!
Olivia decodes well under other conditions that are a complex mix of atmospheric noise, signal fading (QSB), interference (QRM), polar flutter caused by a radio signal traversing a polar path. Olivia is even capable when the signal is affected by auroral conditions (including the Sporadic-E Auroral Mode, where signals are refracted off of the highly-energized E-region in which the Aurora is active).
Currently, the only other digital modes that match or exceed Olivia in their sensitivity are some of the modes designed by Joe Taylor as implemented in the WSJT programs, including FT8, JT65A, and JT65-HF–each of which are certainly limited in usage and definitely not able to provide true conversation capabilities. Olivia is useful for emergency communications, unlike JT65A or the newly popular FT8.
Here is a demonstration of a two-way transmission using the Olivia digital mode on shortwave. I am in QSO (conversation) with KA5TPJ. There are two other Olivia QSOs just below our frequency. Just above us is a lot of FT8 activity. Below the two other Olivia QSOs are PSK31 QSOs. The band is active. Olivia is not dead!
The standard Olivia formats (shown as the number of tones/bandwidth in Hz) are 8/250, 8/500, 16/500, 8/1000, 16/1000, and 32/1000. Some even use 16/2000 for series emergency communication. The most commonly-used formats are 16/500, 8/500, and 8/250. However, the 32/1000 and 16/1000 are popular in some areas of the world and on certain bands.
This can cause some confusion and problems with so many formats and so many other digital modes. After getting used to the sound and look of Olivia in the waterfall, though, it becomes easier to identify the format when you encounter it. To aid in your detection of what mode is being used, there is a feature of many digital-mode software implementation suites: the RSID. The video, below, is a demonstration on how to set the Reed-Solomon Identification (RSID) feature in Ham Radio Deluxe’s Digital Master 780 module (HRD DM780).
I encourage ALL operators in any digital mode such as Olivia, set the RSID feature on as shown in this example. In Fldigi, the RSID is the TXID and RXID (I believe).
Please make sure you are using the RSID (Reed Solomon Identification – RSID or TXID, RXID) option in your software. RSID transmits a short burst at the start of your transmission which identifies the mode you are using. When it does that, those amateur radio operators also using RSID while listening will be alerted by their software that you are transmitting in the specific mode (Olivia, hopefully), the settings (like 8/250), and where on the waterfall your transmission is located. This might be a popup window and/or text on the receive text panel. When the operator clicks on that, the software moves the waterfall cursor right on top of the signal and changes the mode in the software. This will help you make more contacts!
+ NOTE 1: MixW doesn’t have RSID features. Request it!
+ NOTE 2: A problem exists in the current paid version of HRD’s DM780: the DM780 RSID popup box to click does not work. HRD support is aware of the problem. You can still use the textual version that you can select in the settings so that it appears in the receive text areas. If you click the RSID link that comes across the text area, DM780 will tune to the reported signal, and change to the correct settings.
+ NOTE 3: some websites publish frequencies that are right on top of weak-signal FT8, JT65 and JT9 segments. Even if that is a matter of contention, follow the regulations and be kind: DO NOT QRM weak-signal QSOs! AGAIN: make sure that your signal does not cross into other sub-bands where weak-signal modes are active. For instance, do not have any part of your signal at x.074 or higher, as this is the sub-band for FT8, JT65A, and JT9.
Quick Reference: we in the active Olivia group suggest 8/250 as the starting settings when calling CQ on the USB dial frequency of 14.072 MHz with an offset of 700 Hz, on 20m–that translates to a CENTER frequency of 14.0729 MHz. On 40m, 7.072 MHz on the dial with an offset of 700 Hz (and again 8/250) which translates to a center frequency of 7.0729 MHz.
Also, do not quickly switch to other modes without calling CQ for at least a five-minute window. It is really horrid when people call CQ and change settings, modes, bandwidths, tones, every time they call CQ during the same session!
There are several key resources that we in the Olivia community are developing, to make it easier for you to enter into the great world of Olivia. One is an active support e-mail group to which you can subscribe at https://groups.io/g/Olivia — a group containing topical areas of interest which can be filtered so that you are not flooded by email containing topics of which you are not interested. It has a files section, as well, in which we will add helpful how-to instructions and so on.
Another resource is our Facebook group, at https://www.Facebook.com/groups/olivia.hf — also with a files area containing help files. This group is a great resource for getting help from like-minded Olivia digital mode enthusiasts.
Some more eavesdropping on an Olivia QSO:
And, two more:
One last note: Olivia is NOT a weak-signal mode. There are no points won by barely making a contact. In the USA FCC regulations, you are directed to use only the power necessary to make the QSO. Typically, with poor propagation, using Olivia with an output power of 100w is the minimum to establish a reliable circuit. You just cannot go beyond your rig’s duty cycle (don’t burn out the finals in your radio!). You also must be sure that you do not overdrive the audio chain into your radio. Be sure that you do not have RF coming back into your audio chain. Yes, 100 watts is acceptable. Don’t let anyone convince you otherwise. After all, think about RTTY.
Welcome to Olivia! See you on the waterfall.
73 de NW7US
Old, But Still Useful!
This old WWII military training video is still useful regarding Morse code:
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))
Vintage 1944 Radio Operator Training: How to Send Morse Code (CW) by Hand
This one is a pretty cool film:
1939 Film: New Zealand Shortwave Communications; Morse code (CW)
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!
Flight of the Bumble Bee QRP contest
Setting up |
The view from the op table |
Setting up the loop |
The outdoor shack. |
Chameleon CHA P |
Fuelling up before |
Flight of the Bumble Bee QRP contest
Setting up |
The view from the op table |
Setting up the loop |
The outdoor shack. |
Chameleon CHA P |
Fuelling up before |