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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:

–> https://Groups.Io/g/olivia

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

Visit, subscribe: NW7US Radio Communications and Propagation YouTube Channel

The uBITX kit as I predicted, proved so successful when it went on sale on Saturday 9th December, by Monday 11th, Asharr Farhan was telling us all on the BITX20 group, current stock of the first uBITX production run was exhausted!


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!


Steve, G1KQH, is a regular contributor to AmateurRadio.com and writes from England. Contact him at [email protected].

For some time I had been considering the purchase of the MFJ259 antenna analyzer but after a little online sleuthing, came across this little beauty, the FA-VA4 Antenna Analyzer by Funk Amateur in Germany and available through their Box73 website here.





I liked the fact that the cost of the analyzer was about half that of anything else comparable ($140 US including shipping) and that it covered the new 2200 / 630m bands!

I think many amateurs planning on building a system for either of these new bands will find the very affordable FA-VA4 a handy piece of equipment when it comes to working on their LF / MF antenna since most available SWR meters do not cover these frequencies accurately.

Delivery time was fast and everything was very well packaged. The FA-VA4 comes in partial kit form and requires only a short amount of time to put together.


The necessary assembly consists of soldering pin strip connectors, switches, AA cell holders, and the BNC connector. All of the tricky SMD components have been pre-mounted ... total assembly time was less than 60 minutes and everything fired-up nicely, without problems, thanks to the well written instruction / user manual.


Included with the kit are three BNC connectors needed to calibrate the instrument for the highest accuracy. These consist of a 'Shorted' connector, an 'Open' connector and a 50 ohm 'Load' connector (SOL). A simple three-part calibration procedure for all frequencies takes about 15 minute to complete, while the instrument calibrates itself as it scans through all frequency ranges with each connector plugged into the output. Once this task is completed, the analyzer is ready for use.


If you're like me, I think the main use will be to check out and tweak some of your HF antennas using the SWR or Z sweep function. This allows you to set a desired 'center' frequency along with a + / - sweep range and have the display draw a nice plot of your system.

Had my 630m antenna not already been tuned and matched, I would have found the analyzer to be a great help but, thanks to my 'scopematch', that antenna has already been optimised.

All menu features and data entry is via three momentary-contact push switches. Although this might initially seem awkward, it is not, and operation is pretty intuitive.

The main modes of operation are:

Single Frequency SWR  Measurement

courtesy: http://www.box73.com/product/5

Single Frequency Impedance Measurement

courtesy: http://www.box73.com/product/5

Single SWR Measurement Run

courtesy: http://www.box73.com/product/5

Single Run For Impedance Measurement (Resistance and Reactance)

courtesy: http://www.box73.com/product/5

SWR Measurement On Five Frequencies (5 Band Measurement)

courtesy: http://www.box73.com/product/5

As well, all of the above can be viewed in a continuous 'cycle' mode, as inputs are changed and all screens can be saved for future reference.

Additional capabilities include use in an HF Signal Generator Mode (~ 1V square wave @50 ohms), the ability to measure C and L at a given frequency, as a 'dip meter' and to measure cable resonances and determine lengths.

The complete manual may also be downloaded from their website here.

I will soon put all of my antennas to the test and see what work might need to be done to optimize them, particularly my HF half slopers, which, in spite of their great performance, have always proven a bit of a mystery when it comes to pruning them to resonance ... I rather suspect that the sloping wires are more of an impedance tuning stub than a radiator and that most radiation comes from the vertical support tower, not the sloping wire.

All-in-all, the FA-VA4 appears to offer very good value for the money and is a well built, quality test instrument. I think it will become a popular choice among hams, especially those on LF / MF. The only thing different that I would have liked, would be to have a UHF (SO 239) connector rather than a BNC on the output, since most amateurs are using these on their HF systems ... or, the inclusion of a BNC-to-UHF adapter.

If you already use this device, please feel free to add your comments below!
Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

CW - emergency communication ?

Why no love for CW?

Operating CW in Emergencies

Richard Carpenter, AA4OO, is a regular contributor to AmateurRadio.com and writes from North Carolina, USA. Contact him at [email protected].

Many small electronic devices have switching regulators in them that can generate a bunch of Radio Frequency Interference (RFI). This is not my first encounter with RFI-spewing devices. See this article about a automotive 12V-to-USB adapter giving me trouble: This Interference Seems To Follow Me Everywhere

I recently bought a couple of adapters that are physically larger than the one I wrote about. I was thinking that a larger size might allow for a little more filtering and a design that does not radiate. I was half right: one of them works pretty well, the other is an RFI Bad Boy.

Take a look at this short video where I check them out.

 

 

 

This is an Amazon link to the adapter that works pretty well.
Enercell® 2-Port USB CLA Car Charger

 

73, Bob K0NR

The post Radio Frequency Interference From 12V-to-USB Adapters appeared first on The KØNR Radio Site.

Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

In this episode, Colin M6BOY is joined by Martin M1MRB, Edmund Spicer M0MNG and Bill Barnes N3JIX to discuss the latest Amateur / Ham Radio news. Colin M6BOY rounds up the news in brief, and this episode’s feature is The Art of De-soldering.

We would like to thank Kevin Murphy (W8VOS) and our monthly and annual subscription donors for keeping the podcast advert free. To donate, please visit - http://www.icqpodcast.com/donate

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Colin Butler, M6BOY, is the host of the ICQ Podcast, a weekly radio show about Amateur Radio. Contact him at [email protected].

AmateurLogic.TV Episode 112 is now available for download.

Tommy’s battery power solution for Arduino. Peter wants to make new Hams. George builds the ultimate color ‘Heads Up’ Display. And Mike joins us for some special holiday fun.

1:28:37

Download
YouTube

George Thomas, W5JDX, is co-host of AmateurLogic.TV, an original amateur radio video program hosted by George Thomas (W5JDX), Tommy Martin (N5ZNO), Peter Berrett (VK3PB), and Emile Diodene (KE5QKR). Contact him at [email protected].