Archive for the ‘amateur’ Category
Wow. What a radio!
One of the most useful (and, to me, amazing) features of this Icom IC-7610, is the IP+ function, which, when turned on, improves the Intermodulation Distortion (IMD) quality by optimizing the direct sampling system performance. This function optimizes the Analog/Digital Converter(ADC) against distortion when you receive a strong input signal. It also improves the Third-order Intercept Point (IP3) while minimizing the reduction of the receiver sensitivity.
In short: I was listening to an s-0 (i.e., no strength-meter movement) weak signal of a DX station, when right adjacent to the frequency came an s-7 signal, wiping out my ability to copy that weak signal. I turned on the IP+ and the distortion of the adjacent signal disappeared, and once again, I heard the weak signal IN THE CLEAR! WOW!
This video is a quick capture of my running the Olivia Digital Mode on HF, on the 30-Meter band. The transmissions are of a two-way Olivia digital-mode radio conversation between station K8CJM and station NW7US on 12 November 2019 (UTC date). K8CJM is located in Dayton, Ohio, and I am located in Lincoln, Nebraska. I’m running the radio at full power. The radio is rated as being able to handle 100% duty cycle at full power. The radio ran cool, no significant heating.
A few months ago, a lightning strike took out my ham radio station. The antenna was NOT connected, but I did not unplug the power supply chain and my computer from the wall. The surge came in through the power mains, and fried my uninterruptable power supply, the interfaces between my PC and radio, and fried the radio. Thankfully, all of that was covered by my homeowner’s insurance policy, less the steep deductible. My insurance covered all of the blown items, and that provided me this chance to obtain a repack version of the Icom IC-7610. I bought an extended four-year warranty.
CAUTION: Check the documentation of your transceiver/transmitter. NEVER run your radio’s power out at a level that exceeds what it can handle in reference to the duty cycle of the mode you are using. Olivia, for instance, is a 100-percent duty cycle mode. Morse code is NOT quite 100% duty cycle. Nor is SSB, a mode that operates with a duty cycle much lower than 100%. Your radio’s manual should tell you the specifications regarding the duty cycle it can handle! If you run more power than your radio can handle with the given duty cycle of the mode in use, you will blow your radio’s finals or in some other way damage the radio! Beware! I’ve warned you!
Compression and ALC!?
Some have noted that it appears that I’ve left on the Compression of the transmitted audio. However, the truth is that compression was not being used (as is proof by carefully taking note of the zero meter movement of the Compression activity). I had the radio set for 20-Meter USB operation on the Sub VFO. Compression was set for standard USB operation. Note also that the radio was transmitting USB-D1, which means the first data/soundcard input to the radio.
Also, some people complain about my use of ALC, because, in their view, ALC (automatic level control) is a no-no for data modes.
The notion that one must NEVER use ALC when transmitting digital modes is not accurate.
Multi-frequency shift keyed (MFSK) modes with low symbol rate–such as the Olivia digital modes–use a single carrier of constant amplitude, which is stepped (between 4, 8, 16 or 32 tone frequencies respectively) in a constant phase manner. As a result, no unwanted sidebands are generated, and no special amplifier (including a transmitter’s final stage) linearity requirements are necessary.
Whether the use of ALC matters or not depends on the transmitted digital mode.
For example, FSK (Frequency-Shift Keying; i.e., RTTY) is a constant-amplitude mode (frequency shift only). In such a case, the use of ALC will NOT distort the signal waveform.
PSK31 does contain amplitude shifts, as an example, therefore you don’t want any ALC action that could result in distortion of the amplitude changes in the waveform.
On the other hand, the WSJT manual says that its output is a constant-amplitude signal, meaning that good linearity is not necessary. In that case, the use of ALC will NOT distort the transmitted signal-amplitude waveform. You can use ALC or not, as you choose when you run WSJT modes, or Olivia (MFSK).
Nowhere in this am I advocating running your audio really high, thinking that the ALC will take care of it. I am not saying that. I am saying that some ALC is not going to be an issue. You MUST not overdrive any part of the audio chain going into the transmitter!
Transmit audio out of the sound card remains at a constant amplitude, so there will be no significant change in power output if you adjust your input into the radio so that the ALC just stops moving the meter, or, you can have some ALC meter movement. You can adjust your audio to the transmitter either way.
If the transmitter filters have a significant degree of ripple in the passband then you may find that RF power output changes with the selected frequency in the waterfall when there is no ALC action. Allowing some ALC action can permit the ALC to act as an automatic gain adjustment to keep the output power level as you change frequencies.
Linear and Non-Linear
Regarding linear and non-linear operation (amplifiers, final stages): While a Class-C amplifier circuit has far higher efficiency than a linear circuit, a Class-C amplifier is not linear and is only suitable for the amplification of constant-envelope signals. Such signals include FM, FSK, MFSK, and CW (Morse code).
If Joe Taylor’s various modes (in WSJT software) are constant-envelope signals, than class-C works, right? At least, in theory.
Some Additional Cool History
The digital mode, Thor, came out of DominoEX when FEC was added. Here is an interesting history of FSQ that seems to confirm that FSQ is like MFSK, so no problem with a bit of ALC.
The following is from https://www.qsl.net/zl1bpu/MFSK/FSQweb.htm
History – Let’s review the general history of Amateur MFSK modes. The first Amateur MFSK mode developed anywhere was MFSK16, specified by Murray Greenman ZL1BPU, then first developed and coded by Nino Porcino IZ8BLY in 1999. Before MFSK16 arrived, long-distance (DX) QSOs using digital modes were very unreliable: reliant, as they were, on RTTY and later PSK31. MFSK16 changed all that, using 16 tones and strong error correction. Great for long path DX, but nobody could ever say it was easy to use, never mind slick (quick and agile)!
Over the next few years, many MFSK modes appeared, in fact too many! Most of these were aimed at improving performance on bands with QRM. Most used very strong error correction, some types a poor match for MFSK, and these were very clumsy in QSO, because of long delays.
The next major development, aimed at easy QSOs with a slick turnaround, was DominoEX, designed by Murray Greenman ZL1BPU and coded by Con Wassilieff ZL2AFP, which was released in 2009. Rather than using error correction as a brute-force approach, DominoEX was based on sound research and achieved its performance through carefully crafted modulation techniques that required no error correction. The result was a simpler, easier to tune, easily identified mode with a fast turn-around.
DominoEX is widely used and available in many software packages. A later development by Patrick F6CTE and then Dave W1HKJ added FEC to this mode (THOR) but did not add greatly to performance, and at the same time eroded the fast turn-around. The final DominoEX- related development was EXChat, a version of DominoEX designed specifically for text-message style chatting. While completely compatible with DominoEx, it operates in ‘Sentence Mode’, sending each short over when the operator presses ENTER. EXChat was developed by Con ZL2AFP and released in 2014.
Back in 2013, Con ZL2AFP developed an MFSK mode for LF and MF which used an unusual decoding method pioneered by Alberto I2PHD: a ‘syncless’ decoder, which used a voting system to decide when one tone finished and another began. The first use of this idea was in JASON (2002), which proved to be very sensitive, but very slow, partly because it was based on the ASCII alphabet. The new mode, WSQ2 (Weak Signal QSO, 2 baud) combined the syncless decoder with more tones, 33 in total, and an alphabet specially developed by Murray ZL1BPU, which could send each lower case letter (and common punctuation) in just one symbol, resulting in a very sensitive (-30 dB SNR) mode with a 5 WPM typing speed.
In the subsequent discussion in late 2014, between the developers ZL2AFP and ZL1BPU, it was realized that if the computer had enough processing power to handle it, WSQ2 could be ‘sped up’ to become a useful HF chat mode. This required a large amount of development and retuning of the software to achieve adequate speed was involved, along with much ionospheric simulator and on-air testing used to select the most appropriate parameters.
Tests proved that the idea not only worked well, but it also had marked advantages over existing HF MFSK modes, even DominoEX. As expected, the new mode was found to have superior tolerance of signal timing variation, typically caused by multi-path reception, and would also receive with no change of settings over a wide range of signaling speeds.
So this is how FSQ came about. It uses the highly efficient WSQ character alphabet, IFK+ coding, the same number of tones as WSQ (33), but runs a whole lot faster, up to 60 WPM, and uses different tone spacing. The symbol rate (signaling speed) is modest (six tones per second or less), but each individual tone transmitted carries a surprising amount of information, resulting in a high text transmission speed. And it operates in ‘Chat’ (sentence) mode, which allows the user to type as fast as possible since they type only while receiving.
The ability to send messages and commands selectively has opened a huge array of communications possibilities.
What Makes FSQ Different
Incremental Keying – FSQ uses Offset Incremental Frequency Keying (IFK+), a type of differential Multi-Frequency Shift Keying (MFSK) with properties that make it moderately drift-proof and easy to tune. IFK+ also has excellent tolerance of multi-path reception.
IFK was developed by Steve Olney VK2XV. IFK+ (with code rotation) was proposed by Murray Greenman ZL1BPU and first used in DominoEX. IFK+ prevents repeated same tones without complex coding and provides improved rejection of propagation-related inter-symbol interference. In the context of sync-less decoding, the IFK+ code rotation also prevents repeated identical tones, which could not have been detected by this method.
Efficient Alphabet – In FSQ, a relatively high typing speed at a modest baud rate comes about because the alphabet coding is very efficient. All lower case letters and the most common punctuation can be sent in just one symbol and all other characters (the total alphabet contains 104 characters) in just two symbols. (The alphabet is listed below). This is a simple example of a Varicode, where it takes less time to send the more common characters. The character rate is close to six per second (60 WPM), the same as RTTY, but at only 1/8th of the baud rate. (RTTY has only one bit of information per symbol, 7.5 symbols per character, and wastes a third of its information on synchronization, and despite this, works poorly on HF).
No Sync – Another important factor in the design of FSQ is that no synchronizing process is required to locate and decode the received characters. Lack of sync means that reception is much less influenced by propagation timing changes that affect almost all other modes since timing is quite unimportant to FSQ; it almost completely eliminates impulse noise disruption, and it also contributes to very fast acquisition of the signal (decoding reliably within one symbol of the start of reception). Fast acquisition removes the need for the addition of extra idle characters at the start of transmission, and this leads to a very slick system. Add high resistance to QRM and QRN, thanks to the low baud rate, and you have a system so robust that it does not need error correction.
See you on the bands!
In 2008, John Devoldere, ON4UN, and, Mark Demeuleneere, ON4WW, wrote a comprehensive document entitled “Ethics and Operating Procedures for the Radio Amateur.” The purpose of this document was for it to become a universal guide on operating ethics and procedures.
This document was accepted by the IARU (International Amateur Radio Union) Administrative Council as representing their view on the subject. During subsequent Regional IARU meetings it was emphasized that the document be made available to the Amateur Radio Community via all available means, at no cost, and in as many languages as possible.
The document has since been translated into more than 25 languages. In some countries, the document is also offered in printed format and many Amateur Radio websites have a link to the document. Our most sincere thanks go to all our friends who spent hundreds of hours to take care of these translations.
To achieve easier access to all of the existing versions and languages of the document, the authors have set up the Ham Radio Ethics and Operating Procedures web site at:
It contains a listing of all versions/languages, sorted by country, where you can download the translations in any of the following forms:
*PDF or Word documents from various countries
*Directly from the different Radio Societies’ web sites
*A downloadable PowerPoint Slideshow Presentation (available in one of three languages–English, French and Dutch)
John, ON4UN, and Mark, ON4WW
The Olivia digital mode on HF radio is a mode capable of two-way chat (QSO) communication (keyboard to keyboard, like RTTY) over long-distance shortwave (HF) ionospheric propagation paths, especially over polar regions.
If you are interested in more than a logbook QSO (such as is typical with FT8 and other propagation-checking modes) but want to chat with other hams around the world using digital modes, consider Olivia as one option.
This video captures a few moments of two-way conversation on the Twenty-Meter band, up in the sub-band where 1000-Hz digital modes are commonplace. More narrow-bandwidth settings are used in a lower subband in the digital slice of Twenty Meters. More details about the mode are in the files section of this website: http://OliviaDigitalMode.org.
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 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. One reason for this is that there are configurations that use much less bandwidth than 1000 Hz. 16 tones in 250 Hz is our common calling-frequency configuration, which we use lower down in the Twenty-Meter band, with a center frequency of 14.0729 MHz.
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!
+ NOTE: The MixW software doesn’t have RSID features. Request it!
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.
It is my observation that by enabling someone a taste of what can be accomplished on HF (shortwave) spectrum, especially using one of the newer digital modes, that someone has an opportunity for inspiration, perhaps enough to catch the HF fever that is required to move that someone from entry-level to experienced, skilled expert. Right now, the regulations limit the Technician-level license holder to digital operation only on bands that barely propagate (if at all!) during the weak solar cycles. It is a far stretch to postulate that having privileges on dead bands will inspire exploration and tempt the operator to upgrade to a higher license class.
I believe that Technician-class priveledges should be expanded so that entry-level amateur radio operators can get a practical taste of effectively-propagating HF signals on lower frequencies than those frequencies currently available to them for digital operation. And, the allowed mode on these subbands should include digital modes. This “would encourage a sustained interest in Amateur Radio and encourage further development of knowledge and operating skills,” a concept already proven by General-class operators that get enough of a taste that they then pursue the Amateur Extra license.
Comments to me are below the following video section. I also include my response.
In the following video, I share my opinion regarding the ARRL asking the FCC to grant more operating privileges across the many amateur radio allocations on shortwave (HF, or, High Frequencies). The video is my brief takeaway of ARRL’s petition: What is the issue, as a whole, and what the ARRL is addressing–the lack of desire by most current Techs to upgrade. The logic of my perspective concludes that if you give them a taste of lower-shortwave propagation and excitement, then they will want to upgrade. This logic is already proven as applicable by the fact that the General class exists. All this proposal will do is allow the tech to experience what could be very attractive. Just like for the General.
The next two videos are addendums to the first video:
I made a few technical mistakes in the first video. The last video contains corrections and further comments.
Comments Received, and My Response
I have received many responses–some in opposition, some in support. Here are example contrarian responses along with my reply:
[Dear] Tomas David Hood[:] Something for absolutely nothing has never taught anyone anything good, but to want another free lunch. 35 multiple guess easy questions was all that was asked to get general class privileges, but that’s just too hard for the current class. Something for nothing is what sell today, and the ARRL, and probably half the country thinks socialism is the way to reach the new hams I guess. But the ARRL will never get another dime from me. You want a trophy or additional privileges, Get them as everyone else did,, Work for them, study, just a little is all that was asked. Remember, If it didn’t cost anything, it probably isn’t worth anything!
If they are not willing to take a simple test, and yet they want to upgrade, then yes they are the same as saying that we are asking too much, but would participate, you are suggesting, as long as it didn’t require any work or effort on their part, Its a shame.. And I am embarrassed on their behalf… Alexandria Ocasio-Cortez could pass that test, but she would probably agree with you, that people are asking them to be smart and study, and that’s somehow probably racist and just over the line for you.
At this point the ARRL should just say, we are not protecting the spectrum, but about selling the ham radio spectrum to the highest bidders. In this case, they be;live that will be the techs who will purchase HF gear, and of course, the ARRL will benefit hugely from the equipment makers desire to market to the group.
My response is:
What the heck is wrong with selling radios?
But, seriously, which of the many Technicians say that they want to upgrade? That’s the point: the majority of Technician-class amateur radio operators are not upgrading. They get on VHF and above, and are stationary, with few realizing that there’s so much more than the aspect of the hobby evident in their local community.
With little to no exposure to other aspects of the hobby, the typical ham in the current ham-radio culture settles for what is presented by local mentors. Weather spotting, DMR, etc.
Because they have current HF privileges that have so little practical use (CW only on lower frequencies; voice on 10 meters which doesn’t propagate well during this period of no sunspot activity…), they see no incentive to delve into what appears like a waste of time.
The proposal is not giving away the farm. It simply adds a small slice on a limited set of HF bands (but where a signal has a better chance of propagation), allowing for Technician-class operators to get a real sense of the potential waiting for them if they pursue the General.
Then, once upgraded to General, they get even more exposure, and hopefully, see why it is great to be an Amateur Extra.
Tomas David Hood what’s wrong with selling radios. Nothing at all, but if I removed the test that drivers take to show they understand the rules and how to drive, then I can sell more cars and more insurance to poor drivers. Do you or anyone else think that’s a good idea. A few tech’s putting their hands on the plate of those high voltage amps, and maybe, just maybe, someone will believe me when I say some basic testing should be required for HF privileges. Now, all they will have is a cereal box license in my book, and in the opinion of many of my friends, so it;s not just me. If I am wrong, then there are a lot of people that are wrong like me, and they will fight for there hobby. I am a ARRL VE, but I will never test another Ham if this goes through, and I will spend the rest of my days making sure any newcomers realize what the ARRL did to what once was a good hobby, and how a few people didn’t seem to understand why giving away free privileges is always bad for our society, and always bad for our hobby.
Actually I have a real case study that is local,, and yes the guy doid put his hand on the plate, and yes he hit the floor.. and yes, after I found out he was ok,, I think it’s plenty funny,, Yes, they need to study more than that.
Your argument that Technician-class operators will kill themselves because the test is so easy that they will end up electrocuting themselves is yet another Red Herring. Technicians play with dangerous VHF, UHF, SHF equipment, with ominous dangerous aspects deserving respect. If you really think that the General test is the difference between life and death, why even worry? The number of technicians will be nicely reduced to a more acceptable, comfortable number.
I’ve seen Amateur Extra-class operators do the same sort of dangerous, life-threatening stunts.
The issue you are highlighting is a different problem that must be solved separately from the idea of creating a more practical incentive; all tests should be improved in such a way as to foster greater technical knowledge and awareness of all aspects of the hobby.
Better mentoring. Less us-vs-them. More education. More community. All of these should be explored and enhanced. Solve the problem, instead of ostracizing. And, realize that this proposed change is NOT a dumbing-down maneuver to give away the ham radio hobby to the unclean.
In the 1990s while living in eastern Montana, I had the amazing experience of reuniting two soldiers that served in the Devil’s Brigade. They both trained near Helena, Montana.
One day, I was operating on the amateur radio shortwave Ten-Meter band, and a gentleman answered my, “CQ, CQ, CQ, this is N7PMS in Montana, Over”. I took notes of our conversation.
The next day, when again I called for any station to answer my call for a conversation, another fellow, from Canada, answered me. I learned something amazing: Both of these two men mentioned that, during World War Two, they both were in the same special forces unit, training near Helena, Montana.
One of these Veterans served in the Canadian Armed Forces, and the other in the American Armed Forces. Listen to my story, for the full details of this amazing experience I had as an amateur radio operator.
Jump to 3:22 if you wish to skip my introduction to the story, during which I give some background on when and so on:
This certainly was one of the most memorable moments in my amateur radio hobby experience! The joy of reuniting friends is good.
The 1st Special Service Force (also called The Devil’s Brigade, The Black Devils, The Black Devils’ Brigade, and Freddie’s Freighters), was an elite American-Canadian commando unit in World War II, under command of the United States Fifth Army. The unit was organized in 1942 and trained at Fort William Henry Harrison near Helena, Montana in the United States. The Force served in the Aleutian Islands, and fought in Italy, and southern France before being disbanded in December 1944.
The modern American and Canadian special operations forces trace their heritage to this unit. In 2013, the United States Congress passed a bill to award the 1st Special Service Force the Congressional Gold Medal.
Thank you for watching, and sharing. Comments are welcome: do you have a memorable moment in your radio hobby experience on the air?
73 de NW7US
My first QSO (and, yeah, it was with Morse code) was petrifying and…
What’s your story of your first QSO?
73 de NW7US