Archive for the ‘Technology’ Category
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
Some of you wanted to see the complete version, uncut, of this video in which I discuss the differences between CB and the Amateur Radio Service. This is in response to the recent episode in which the NCIS writers missed a great opportunity to discover the vibrant reality of the current amateur radio service in the United States of America.
The previous version of the video was prematurely cut short by just over three minutes. This version includes that ending. I also remove some of the low-end rumblings from the vehicle. This version should sound a little bit less annoying. Hopefully, the quality of the video is sharper, as well. This version was edited by Adobe Premiere CC 2017.
I appreciate the many comments, views, and shares. Please subscribe, too!
73 from Omaha!
The FCC has authorized amateur radio use of the 630 and 2200-meter bands, effective October 16, 2017, providing registration procedures have been followed and no objections are received within 30 days.
The PLC (Power Line Communications) database is live and hams may begin registering immediately. They may begin operating on 472 kHz (630 meters) and 137 kHz (2200 meters) as early as October 16 if they register today and receive no objection in the next 30 days. Hams may not operate on the bands without going through this process.
Please fill out the UPC Form, today, to register your station, even if you don’t have any plans on transmitting on these new bands.
It is imperative that all amateurs register, even if they don’t plan to use these bands in the near future, as the FCC rules prohibit UTC (the Utilities Technology Council) from deploying PLC in these bands closer than one (1) kilometer from registered stations. Registration now will protect your ability to use our new MF/LF bands in the future.
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
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
In this episode we talk about the Yaesu System Fusion DR-2X repeater, the upcoming Solar Eclipse and more.
There is some interesting new features on the DR-2X repeater over the DR-1X that came out a couple years ago, but there is also something that it doesn’t have. Some of these features, I wish that we had on our club repeater, but those features are not enough for us to go out and buy this version.
There are a lot of special event stations that are going to be on the air around August 21st this year when the full solar eclipse occurs. This is the first time since 1918 that a full solar eclipse has gone from one side of the US to the other. I unfortunately am to far south to the see the full eclipse, but I should get about a 75% one here in the DFW area.
We also talk about some other stuff, but you are going to have to check out the show notes and listen to the episode to find out what that is.
73s de Curtis, K5CLM
In this episode of the Everything Ham Radio Podcast, we talk with Garrett Dow, KD6KPC, the creator of RepeaterBook.com. RepeaterBook is a free online repeater directory that covers all of the US and Canada as well as several other countries around the world.
You can use RepeaterBook directly from its website, or through its app. You can find the app on IOS, Android and Kindle. RepeaterBook has done a great job on getting and maintaining the information of about 35,000 repeaters thank in a large part to about 95 admins that maintain the records in their assigned areas and from the ham community at large.