Getting to know GNURadio

Make a working receiver and more on your computer

At our January 2024 monthly general meeting (held via Zoom) Kevin McQuiggin VE7ZD/Kn7Q presented on GNURadio,

What is this GNU?

Aside from the wild beasts of Africa, GNURadio is an open-source software toolkit that provides signal processing blocks to implement software-defined radios (SDRs) and other digital signal processing systems. It allows users to design, simulate, and deploy radio systems in software, enabling the development of a wide range of radio communication applications.

Here are some key aspects of GNU Radio:

Software-Defined Radio (SDR): GNU Radio is widely used in the field of SDR, where radio functionality is implemented in software rather than hardware. This provides flexibility, allowing users to modify and experiment with radio protocols, waveforms, and processing algorithms.

Signal Processing Blocks: GNU Radio provides a collection of signal processing blocks that users can connect to create custom signal flow graphs. These blocks perform functions like modulation, demodulation, filtering, frequency shifting, and more. Users can combine these blocks to create complex radio systems.

Wide Range of Applications: GNU Radio can be used to develop a variety of applications, including but not limited to:

• Communication Systems: Design and implement various communication protocols, such as AM, FM, SSB, LTE, Wi-Fi, etc.
• Radar Systems: Create radar signal processing chains for applications like target detection and tracking.
• Radio Astronomy: Process and analyze radio signals from space to study celestial objects.
• Wireless Sensor Networks: Implement communication protocols for distributed sensor networks.

Extensibility and Customization: Users can extend GNU Radio by creating their own signal processing blocks, allowing for customization and the integration of specialized functionality.

Graphical User Interface (GNU Radio Companion): GNU Radio comes with a graphical tool called GNU Radio Companion (GRC), which allows users to visually design signal processing flow graphs. GRC simplifies the creation of complex radio systems by providing a drag-and-drop interface for connecting signal processing blocks.

Active Community: GNU Radio has a vibrant and active user community that contributes to its development. This community-driven approach results in continuous improvement, updates, and the sharing of knowledge and resources.

GNU Radio is widely used in academia, research, and industry for prototyping, experimenting, and implementing various radio communication systems. It plays a crucial role in advancing the field of software-defined radio and empowering individuals and organizations to explore and innovate in the domain of wireless communications.

You can watch Kevin's presentation on YouTube;

Kevin has included several links at the end of his presentation

Further Information:

In September 2023 Our Communicator journal included an excellent article by Kevin titled: "The  “What’s It?” Of WSPR" that touched on many of the same principles as GNURadio. 

Another of Kevin's articles, titled: "Introduction to Digital Radio" was published in our January 2024 edition. Both of these will provide excellent supporting information for Kevin's GNURadio presentation.

 

~

The January - February 2024 SARC Communicator

A great way to start 2024!

The January - February 2024 Communicator, digital periodical of Surrey Amateur Radio Communications is now available for viewing or download.

Read in over 145 countries, we bring you 120 pages of Amateur Radio content from the Southwest corner of Canada and elsewhere. With less fluff and ads than other Amateur Radio publications, you will find Amateur Radio related articles, projects, profiles, news, tips and how-to's for all levels of the hobby.

You can view or download it as a .PDF file:  

Download the Communicator January - February 2024

or read it on-line

Previous Communicator issues are at:

https://ve7sar.blogspot.com/search/label/The%20Communicator

and a full index is HERE.  

As always, thank you to our contributors, and your feedback is always welcome. 

The deadline for the next edition is February 15th.

If you have news or events from your club or photos, stories, projects or other items of interest from BC or elsewhere, please contact us at communicator@ve7sar.net

73,

John VE7TI
'The Communicator' Editor

The January - February 2022 SARC Communicator

 

Over 120 Pages Of Projects, News, Views and Reviews

2022 here we come! 'The Communicator' digital periodical of Surrey Amateur Radio Communications is now available for viewing or download at https://bit.ly/SARC22JanFeb

Read in over 140 countries now, we bring you Amateur Radio news from the South West corner of Canada and elsewhere. You will find Amateur Radio related articles, projects, profiles, news, tips and how-to's. 

This month a special feature on CW, including its history, modern day mentions and how to best learn it.

You can view or download it as a .PDF file from:  

https://bit.ly/SARC22JanFeb

Previous Communicator issues are at https://ve7sar.blogspot.com/search/label/The%20Communicator

As always, thank you to our contributors, and your feedback is always welcome. 

The deadline for the next edition is February 20th.

If you have news or events from your club or photos, stories, projects or other items of interest from BC or elsewhere, please email them to communicator@ve7sar.net

Keep visiting our site for regular updates and news: https://ve7sar.blogspot.ca    

73,

John VE7TI

'The Communicator' Editor

SARC-SEPAR November 10 Presentation on DMR

 Here is a guide to getting started on DMR

DMR stands for Digital Mobile Radio and is a European-developed international standard of digital radio. This new and versatile technology covers voice and data transmissions, along with conformance testing. It is an affordable digital solution to analog radio.

The only drawback is programming, which is more complex than standard amateur radio. DMR requires a 'codeplug' which is a file containing program information. With most analog ham radios you can convert a DMR code plug from one radio brand to another, using CHiRP for example. As mentioned during the presentation, every manufacturer seems to roll their own software, thus ensuring different nomenclature, and organization of their dialog boxes.

Its not for the faint of heart or for the beginner, so its best to consult someone in your area who may have a codeplug ready to go. For us that resource is Doug Pattengale VE7CQT, who gave an excellent PowerPoint presentation on the subject to a combined Zoom audience of SARC and SEPAR members. 

According to Doug, some of the worst radios don't include the ability to fully export or import the code plug elements so that tools like spread sheets can be used for bulk editing. There are tools 'out there' that facilitate this conversion from one proprietary software to another. For free! Have a look at this tool as it handles the TYT MD UV380 or 390 model in question. 

Doug has used it to convert an AnyTone code plug in the past, and he reports that its amazingly powerful and convenient. Once you get to know how it works, it can do in a few minutes what would take hours of work to manipulate in a spread sheet. An added benefit is that it compensates for missing functionality like sorting, re-ordering and cut / paste that the native CPS software lacks.

http://n0gsg.com/contact-manager/

- this is a stand alone .exe file. You just drop it into a folder and run it. No hidden files, overhead, install or uninstall. Just delete it, and its gone.

 

Here is a link to Doug's presentation:

https://drive.google.com/file/d/1d4qRTKzhX46fFVagdHUq1UAy2SLNrc55/view?usp=sharing

And here is a complete guide to getting started in digital radio, courtesy of the Galway Radio Club:  Digital-Radio-Operating-Manual-v2.pdf (galwayradio.com)

~

An Inexpensive Interface Cable for Baofeng Transceivers

Much less expensive than the individual components 

I know many of us have Baofeng and Wouxon transceivers. I recently came across this tip to cannibalize an inexpensive mic for the cable, which can then be easily interfaced to a TNC or other digital device.

The Baofeng UV-5R and similar radios are extremely inexpensive dual band (2m/70cm) HT's that are widely used for FM voice communication. But what about using them on packet radio? Yes, this is possible, but a number of people have had problems with either home made cables are some that were bought commercially. The major problem is that the radio keys, but does not unkey. It seems to be a grounding problem because when you bring your hand close to the radio, it then unkeys. More information on how to fix this momentarily. 

One way to overcome this is to make your own radio/TNC cable using a speaker/microphone that is designed for the Baofeng radio. You then cut off the microphone and just use the cable and connector. This may sound expensive, but as it turns out, speaker/mics are available for the Baofeng on line in the US$5 range. Do a search on Amazon for "Baofeng Speaker" and you will find them. You will also need a 5 pin DIN or 9 pin serial plug for the other end of the cable. 

You can buy these DIN Plugs on the TNC-X web site for $2 and serial plugs are universally available. Locally Lee’s Electronics is my choice for supplier.

Here is the Baofeng Speaker/Mic purchased from Amazon.The pin out for the plug is:

• TX Audio: Ring on big plug
• Ground: Sleeve on small plug 
• PTT: Sleeve on big plug 
• RX Audio: Tip on small plug

In the photo above, the 3 screws that hold the microphone rear plate in place have been removed and it is opened up. You can see that the wires are labelled on the printed circuit board, which makes it easy to figure out which wire is which. On this microphone the connections are as follows:

• Red = TXAudio
• White = Ground
• Black = PTT
• Green = RXAudio

NOTE 1: Some of these mics have the M- (ground) and SP+ (RXAudio) wires reversed. Since these wires are connected to the speaker, this doesn't matter for the operation of the speaker/mic, but it does matter for TNC connections. Typically the white wire is ground and the green wire is RXAudio. To be certain, clip the microphone off the cord and check the continuity between the white wire and the sleeve on the small plug. 

NOTE 2: A few Baofeng speaker/mics don't work.  It is suggested that before you cut the cable, make sure the speaker/mic works with your Baofeng HT.  If it does not work, the cable probably won't work either. 

The next step is to strip the wires and tin them with solder. Notice that the black wire is significantly shorter than the other wires. 

Solder a 2.2K resistor onto the pin where the PTT (black) wire is going to be attached. (This will solve the problem of the TNC getting stuck in transmit. Use as small a resistor as will fit, wattage is not important. Next solder the connector on to the remaining wires. 

Here's the completed cable, ready to go! As you can see it is not a difficult assembly process. However, if you would like to buy one already built, they are available for $20 plus shipping from https://www.tnc-x.com/ This company also sells TNC kits.

 ~ John VE7TI 

   19-02

HamShack Hotline

 

Yet another emergency communications option

Started in 1998, Hamshack Hotline (HH) is a FREE dedicated Voice over IP (VoIP) telecom service for the Ham Radio community. It is incorporated and not for profit.

You may ask: “Why do we need this?” In an emergency, it is proven time and again that any communications are an asset, and as Amateurs, that’s what we do best.

The next SARC Communicator will have a complete story on this service, and suggestions on how to get started. I did a presentation via Zoom about HH at our December meeting and since then 3 members have joined with more indicating an interest in joining.

It was pretty lonely on HH here in Surrey but the map is getting fuller...

HamShack Hotline as of 20-12-13 - https://www.google.com/maps/d/viewer?mid=1Awk65-qRwUWTGWaN3TjOO63GSoJJyu_3&usp=sharing 

I'm not feeling as lonely anymore.  Watch for story in next Communicator https://ve7sar.blogspot.ca

Watch this video for an overview: https://youtu.be/dMr9a_6CuNE

Lots of additional information on the HH FaceBook page as well: https://www.facebook.com/groups/hamshack

~ John VE7TI

More On SDR Dongles

 

A Closer Look

We had an earlier article about SDR and SDR dongles. I recently played with a nano version. It is probably a knock-off of the NooElec.

I can tell you my findings:

• It has to be connected on the USB computer port with an extender, otherwise the electric noise generated by the computer makes it unusable and completely deaf.
  
  
• It has not much shielding it; acceptable if it is not case to case to the electric noise generator, but at several centimeters apart, it is fine. I tried to shield it in metal, and it did not make any difference, in various test situations. I suspect it is already shielded somehow inside, or partly shielded inside.
  
  
• In the commercial FM band it is a cheap stereo and more important, an RDS receiver. It knows to display the name of the station, the songs that are played in that moment and whatever digital info the station sends in addition to the analog signal. The sensitivity in FM is way worse than 2 microvolts. Any dedicated commercial receiver amplifier, including my roommate’s Yamaha 2 micro V (and every single FM radio in the apartment we have, including clock radios, MP3 portables (the radio part) are more sensitive than the SDR dongle. Also, I am using a proper dipole antenna on the balcony, connected with coax cable to the SDR dongle, while all other 7 receivers have just a small piece of wire. I estimate somewhere at 30 – 50 microvolts sensitivity in the 88 – 108 MHz band.
  
  
• The characteristics differ very much on the Rx bands and require adjustment from the RTL dongle settings. That means RF Gain; RTL AGC; Tuner AGC. It seems it does not like the 50 MHz band and the sensitivity is not great in this band. I confirmed the bad findings of everybody writing about this issue on the Internet.

• In the 144 MHz band, with a good dipole, it receives everything the Kenwood 7950 and the Chinese walkie-talkie receives. It likes this band and it has good sensitivity. All repeaters from Victoria, Port Angeles, Nanaimo, Cowichan are 59.

• It also likes the marine band, air traffic band and the weather band. They are all around 150 MHz and once the settings are done for one station, they can be kept in the weather, marine, 2 meter bands.

• It is stable. I did not feel the need for a more stable oscillator. It did require adjustment in the software, -200 ppt for my dongle. This is considered a huge adjustment. I verified with encapsulated quartz oscillators (32 MHz, 125 MHz, 150 MHz, the 28.197 CW beacon), and indeed it needs that huge adjustment.
  
  
• The CB band and the beacon on 28.197 MHz (VE7MTY, Pitt Meadows, continuous, CW) are in a band where the RTL dongle is not so sensitive. The beacon (nearby me) booms in my SONY ICF7600G portable radio, with its telescopic antenna. The SDR dongle with a CB whip on the balcony receives it almost OK, but only because I was hunting for the beacon and I knew where it is. The beacon’s signal barely produces a trace in the display spectrum, and I am nearby it (exactly 13.89 km away).
  
  
• There are images everywhere. The FM band (88 – 108 MHz) can also be received on 30-50 MHz. The worse thing to do is to use an upconverter, as I saw so many on the Internet, with an NE612, and wide non-tuned input. I tried, and the images kill any useful signal. In the end I did 2 converters, in order to cover 3.5 MHz to 30 MHz, one for the lower part and one for the upper part. I used NE612, attacked by an amplifier with a BF998 in front. I have a tuning circuit just at the antenna, and 2.4 K resistor + coil in the output of the BF998 drain. The source terminal is connected directly at the ground and the BF998 is power supplied with 9 V (12 V is max in datasheet, and it does burn-up beyond 12 V). The oscillator is an encapsulated 3.3 V powered oscillator, in a socket, to easily changed. The best it worked for me is at 150 MHz, so stay away from FM commercial band and upconvert the shortwaves into a sensitive band that the SDR dongle likes. I can adjust the signal from the oscillator to the value from the NE612 datasheet, but actually it does not make any difference even if it is provided with 3 V (NE612 has a buffer in it before the mixer).
  
  
• The only program that totally works in Windows is SDR Sharp. It has plugin to decode CTCSS tones and display their value. All other programs partly work (not all modulation types; there are workarounds for stereo; workarounds for drivers and so on). SDR Sharp simply works, all options, everything that the hardware is capable of.
  
  
• The noise of the first element in the SDR dongle must be better than the BFR91A. I tried a wide range untuned amplifier with 1 BFR91A, and it did not bring in anything, just noise. The situation changed when I put a SAW 88 – 108 MHz (3 pin filter) in front of the BFR91A, and it helped.
  
  
• It does not run hot. Whatever other users noticed with old SDR dongles is no longer an issue with my SDR small dongle.

[Right] This is my upconverter for the SDR dongle, inspired from many articles, but not a copy. I always put the dual gate MOSFET BF998 with the S at the ground and the D in a series 2.2 KΩ plus 1 mH molded shock. The BF998 has a different behaviour than a BF981, and very much different than a 40673.

The values are for the 10 MHz - 30 MHz upconverter. With this upconverter in front the combination SDR dongle + converter is more sensitive than the SONY 7600G - probably somewhere close to 1 micro V. But it has to be adjusted every 500 KHz or so, otherwise the 28.197 MHz beacon is lost .

Final conclusions:

• The SDR dongle is the cheapest 2 meter receiver a ham radio can buy, and works as a receiver on par with dedicated equipment, which is generally limited by the line of sight, not by sensitivity. A beginner can listen to the weekly nets for some $8–11 CAD, shipping and taxes included.
  
  
• The SDR dongle is the cheapest FM commercial RDS receiver one can have, capable of displaying the digital data continuously transmitted by almost all stations in Vancouver.
  
  
• The SDR dongle was not meant as a general coverage receiver. It was designed as a DVB-T television European standard receiver, and probably it is best for that purpose.
  
  

~ Daniel VE7LCG

19/01

Tech Topics: Review Of An SDR Dongle

The SDR Dongle 

SDR = software defined radio

Having already a conversation with VE7TI (John) about an older generation of SDR dongles I felt compelled to buy a new one, in 2018, a much smaller one, also from China. Most probably what I bought is a knockoff of a NooElec micro dongle. It was in sale at the time, for $7.87 CAD, shipping and taxes included, from aliexpress.com. It came with a remote control, an antenna and a CD with drivers. I discarded all those accessories, which are totally unusable if somebody wants to use the SDR dongle as a general receiver, and not as a DVB-T PC adapter, as intended.

I would like to start my review by underlining exactly that, the SDR dongle I am reviewing was not designed to be a general receiver, as I use it.

My first action was to install it on the computer, on a USB port, and to install drivers and software for it. I followed the instructions from www.rtl-sdr.com. It is tricky to have the drivers work in Windows 10, but if the instructions are followed exactly as in the given website, it works.

Some conclusions

• 
  The only software that completely works in Windows 10 is SDR sharp. It has various useful plugins, like a plugin for detecting the CTSS tones. Many plugins do not work with the last version of SDR sharp. It is free. A close competitor is HDSDR, which does not know how to decode stereo FM. All other programs I tried partially worked (they do not know all modulations types, have unclear settings, and so on).
  
  
• It has to be connected on the USB computer port with an extender, otherwise the electric noise generated by the computer makes it unusable, completely deaf for useful radio signals. I used my own accessories, in order to adapt the MCX antenna connector from the dongle to my antennas: 
  
  
• Caging the SDR dongle does not help much; if it is not case to case to the electric noise generator, but several centimeters apart, it is fine. I tried to cage it in metal and it did not make any difference in various test situations. I suspect it is already somehow shielded or partly shielded inside.
  
  
• In the commercial FM band it is a cheap stereo and more important, a RDS (radio data system) receiver. It knows how to display the name of the station, the songs that are played at that moment and whatever digital info the station sends in addition to the analog signal. The sensitivity in FM is way worse than 2 microvolts. Any dedicated commercial receiver-amplifier, including my roommate’s Yamaha 2 microV, every single FM radio in the apartment we have, including clock radios, and MP3 portables (the radio part) are more sensitive than the SDR dongle. I am using a proper horizontal dipole antenna on the balcony measuring 71 cm each leg, connected with coax cable to the SDR dongle, while all other 7 receivers have just a small piece of wire as antenna. I estimate the sensitivity in the 88 – 108 MHz band somewhere at 30 microvolts . It is expected the SDR dongle would be less sensitive in the FM band, due to the wide frequency bandwidth. I limited the bandwidth from 250 KHz to 180 KHz and there was a slight improvement.
  
  
  
• The sound in the FM band is not great. Even at 250 KHz, wide band FM (maximum in SDR sharp program), has audio quality that is just bearable. This is not exactly acceptable. I will not replace any of the radios with this SDR dongle, even though it displays data.
  
  
• The characteristics differ very much on the Rx bands and require adjustment at the RTL dongle settings. That means RF Gain; RTL AGC; Tuner AGC. 
  
  
• It is stable. I did not feel the need for a more stable oscillator. It did require adjustment in the software, 218 ppm as in the above picture for my dongle. This is considered a huge adjustment. I verified this with encapsulated quartz oscillators (32 MHz, 125 MHz, 150 MHz, the 28.197 CW beacon), and indeed it needs that huge adjustment.
  
  
• It seems it does not like the 50 MHz band, and the sensitivity is not great in this band. I confirmed the poor reports as everybody writing about this issue on the Internet experienced the same result, although I hear some local ham radios almost every evening. They never say their callsigns, so I just presume they are ham radios since they are in a ham band.
  
  
• On the 144 MHz band, with a good dipole, it receives everything the Kenwood 7950 and the Chinese walkie-talkie receives. It likes this band and it has a good sensitivity. All repeaters from Victoria, Port Angeles, Nanaimo, and Cowichan are 59. Probably the path is more important than the sensitivity in this case, too. I am at 103 meters above sea level. There are some images for strong local repeaters.
• It also likes the marine band, air traffic band and the weather band. They are all around 150 MHz and once the settings are done for one station, they can be kept for the weather, marine, 2 meter bands.
  
  
• The CB band and the beacon on 28.197 MHz (VE7MTY, Pitt Meadows, continuous, CW) are in a band where the RTL dongle is not so sensitive. The beacon (nearby me) booms in on my SONY ICF7600G portable radio, with its telescopic antenna. The SDR dongle with a CB whip on the balcony receives it almost OK, but only because I was hunting for the beacon and I knew where it was. The beacon’s signal barely produces a trace in the display spectrum, and I am nearby it (exactly 13.89 km).
  
  
• There are images everywhere. The FM band (88 – 108 MHz) can also be received on 30-50 MHz. The worse thing to do is to use an upconverter, as I saw so many do on the Internet, with a NE612 integrated circuit, and wide non-tuned input. I tried, and the images kill any useful signal. In the end I did 2 converters, in order to cover 3.5 MHz to 30 MHz, one for the lower part and one for the upper part. I used an NE612, attached to an amplifier with a BF998 in front. I have a tuning circuit just at the antenna, and a 2.2K resistor + coil in the output of the BF998’s drain. The source terminal is connected directly at the ground and the BF998 is supplied with 9 Volts (12 V is max in the datasheet, and it does burn after 12 V). The oscillator is an encapsulated 3.3 V powered oscillator, in a socket, to easily change it. The best the dongle worked for me is in the 150 MHz band, to stay away from the FM commercial band and to upconvert the shortwave into a sensitive band that the SDR dongle likes. I can adjust the signal from the oscillator to the value from the NE612 datasheet, but it actually does not make any difference, even if it is attached with 2 Volts (NE612 has a buffer in it before the mixer).

• The noise of the first element in the SDR dongle must be better than that in the  BFR91A. I tried a wide range untuned amplifier with one BFR91A, and it did not bring anything new, just noise. 
  
  
• The situation changed when I put a SAW 88 – 108 MHz (3 pin filter) in front of the BFR91A, and it helped.

• It does not run hot. Whatever other users noticed with old SDR dongles is no longer an issue with my 2018 SDR small dongle.

Final conclusions

• The SDR dongle is the cheapest 2 meter receiver a Ham can buy, and works as receiver on par with dedicated equipment, which is generally limited by line of sight, not by sensitivity. A beginner can listen to the weekly nets for some $8–11 CAD, shipping and taxes included.
  
  
• The SDR dongle is the cheapest FM commercial RDS receiver one can have, capable of displaying the digital data continuously and transmitted by almost all stations in Vancouver. 
  
  
• The SDR dongle was not meant as a general coverage receiver. It was designed as a DVB-T television European standard receiver, and it is probably better for that purpose.

A Postscript…

In the NI Multisim schematic you see a LED with a big resistor in series. It is not a mistake.

All LEDs I use are from China. The 3 mm ones I bought extremely cheap (I think they were 200 or 500 in the bag). The white ones are the most sensitive, and light at several microamps. I need to use resistors between 150 K (for BLUE) and 300 K (for WHITE) in series with the LEDs for 12 Volts power supply.

Now I understand what kind of LEDs they use in the portable lit antennas for walkie-talkies they sell for Baofeng. They light OK. Smaller resistances means burned LEDs. I tried the old values from various published schematics, and NO, they are not OK for the bags of LEDs I have.

~ Daniel VE7LCG

18/12

A Windows 10 Tip For Hams

Keep those specific drivers from updating

Does this sound familiar? You install a new piece of hardware and finally get it working. Then Windows updates and it no longer works! Likely what has happened is that the device driver also updated and is no longer compatible. The solution for older Prolific PL-2303 HXA/X  clone chips used in serial to USB converters is to use a driver release older than vn3.4 Each time you turn your computer off, the latest driver is reloaded due to windows auto-update (or if you unplug and re-plug the device into a USB port). Note that this generally does not affect genuine Prolific devices.

To avoid that, a recent work-around exists and has been published by Microsoft. It's a tool named ‘wushowhide.diagcab’ (Show and Hide Update). It allow you to inhibit auto-update for a particular program or driver (Prolific in this case).

For more information and where to download this tool, take a look at this article: KB3073930 How to temporarily prevent a driver update from reinstalling in Windows 10.

I have tested it and it works fine. The only problem
with it is that it reloads the latest driver when you plug the device into a never before used USB port. So, if you change the place of connection, you should manually set the driver to vn3.3, but you have to do that only the first time you use this port. Next time, the driver remains at vn3.3 and never upgrades to vn3.6. 

More information: https://support.microsoft.com/en-ca/help/3073930/how-to-temporarily-prevent-a-driver-update-from-reinstalling-in-window

Download: http://download.microsoft.com/download/F/2/2/F22D5FDB-59CD-4275-8C95-1BE17BF70B21/wushowhide.diagcab 

18/09

My Weekend Test of FT-8

It gets through, even on a compromised antenna

I haven’t been keeping up with my QST magazine reading but had heard about FT8 when it showed up online at some point in 2017. When my friend Clyde Feero VE7CKF mentioned he had set it up recently I knew it was time for me to try it out too.  So this weekend I decided I should spend some time reading about FT8 and see what all the hype is actually about. I watched some YouTube videos and I decided to set it up myself. It was far easier than I thought it would be.

First let me give you an idea of my previous experience with digital modes. I have made less than 100 contacts using PSK31 on Ham Radio Deluxe Digital Master 780. I’ve used it enough to confirm my abilities and my shack’s setup.  I have an iCom 7300 with an end fed wire and 20m dipole for antennas. Both of my antennas are very low from to ground at only about 8 feet up. Even with this compromised antenna system, I’ve made PSK31 contacts as far as South America and Europe.

FT8 is one of the newest digital modes available to amateur radio operators.  It is very popular with anyone wanting to make distant contacts using low power or compromised antennas.  If you’ve ever thought about trying a digital mode like JT65 or PSK31 you might just want to try FT8 for yourself.

Compared to the DM780/PSK31 I found WSJTX/FT8 extremely simple only requiring a few things. You need to configure your radio, sound card and enter your callsign/gridsquare.  With DM780/PSK31 you need to setup some macros. I setup WSJTX software in as little as 5-10 minutes. If your like me and use Ham Radio Deluxe you can still use it for advanced rig control and use WSJTX for FT8. It has an option to select HRD as your radio.  There are also logging abilities supported by WSJTX but I didn’t experiment with them yet. LOTW is still being setup to accept FT8 contacts and contesters are waiting for N1MM to support FT8 as a mode, but it’s only a matter of time.

An FT8 QSO exchange is completely automated by the software. There is an option to perform each step in the QSO exchange manually but when it comes to digital modes there seems to be some desire to have everyone follow a common flow. You probably won’t be actually having a conversation with basic FT8 but instead a quick exchange of contact info.

It’s important that your computer’s clock be accurate because every 15 seconds a cycle completes and a new one begins. If you monitor for awhile you’ll notice every 15 seconds call signs will show up.  Some of the call signs are people calling CQ and others are those in the middle of their QSO exchanges. I’ve provided some reference links below and you can setup NTP (Network Time Protocol) to keep your PC clock in sync.

When you respond to CQ you’ll be sending your callsign and grid square. So this can be a little confusing at first when you notice the callsigns and other numbers displayed. You only need to double click on a CQ and the software will start transmitting. If the contact responds back to you they will send you your signal report. Once you each have these details your 73’s begin and your finished with your QSO.

I made my first FT8 contact with N4CAP Jeff Clouse in Jamestown North Carolina, who was 3857 km away from me using the grid square reference.  I was only running 25 watts on 20 meters and I must emphasize that for me to make this contact I just picked his call sign in a list I saw every 15 seconds.  I then double clicked his call sign on my mousepad.  I did nothing else!! Yes it was just that easy.

You can view a screenshot [right] but the software automatically sent him my callsign and grid square. He then responded to me giving me a -22db signal report. I sent him a -14db signal report for his CQ call. He sent me a roger roger 73 and I returned with a 73. End of call, and he began to call CQ again. All of this took less than 1 minute 15 seconds!!

Call it beginners luck I guess but I tried a second contact and didn’t have the same success I had the first time.  You can view [below] where I responded to the CQ of W1JGM but he didn’t answer me. Since I was already monitoring his frequency I noticed someone else exchanging with him and the software stopped transmitting automatically. When the exchange was done I only needed to time my ‘Enable Tx’ again to try a second time. This is where the computer clock and the 15 seconds cycle applies.  I needed to transmit during the send period and not after. I had no luck, but again it either means he could not hear me or chose not to respond to my weak signal.

To get setup for FT8 you’ll need to download and install WSJTX software for your computer.  Since it is available on Windows, Linux, and Mac I decided to try setting it up on my MacBook. This is my first attempt at using digital modes on my Macbook using Apple’s native MacOS, but have previously used Windows on BootCamp for HRD.

For me using the iCom 7300 for digital modes is a little easier than some radios because it is essentially seen as a sound card when you plug in via USB to a computer; so I didn’t need to use a SignalLink sound card. The WSJTX software lets you pick which audio interfaces you want to use and has a huge selection of predefined radios for CAT control.  There is also a “Test CAT” and “Test PTT” feature so you’ll at least be able to confirm your radio is connected well.

Some advanced setup steps might be required to ensure your radio is setup for data mode and not SSB.  You’ll want to confirm your power output is low 25 watts or less to start with and the ALC is not overdriving the radio.  Your computer will be sending audio to the radio and it may be too strong and overdrive the transmission. The main reason you don’t want to overdrive the transmission is to keep your signal clean and not produce splatter.

While I was trying to respond to a few CQ calls that didn’t get picked up I did notice my signal was getting out all over the world.  Kazuhiko Nishimura JG0CQK located near Japan’s Eastern coastline was approximately 7453 km away picked up my attempts at answering other calls in North America. How do I know this? Well the http://pskreporter.info site supports FT8 mode and provides me this info along with all the other stations that received my transmissions.  This is an excellent tool for proving the low power/efficiency of the FT8 mode at my station without even making a single contact. It also proves the FT8 mode is very popular because so many people are listening and volunteering their signal reports. The reporting feature of WSJTX is turned off by default, but I would encourage everyone to enable it to help others with their reports.

My 25 watt compromised antenna signal also made it to Hawaii, and Bermuda. I covered the East coast of North America, Florida, Southern California and various places in between.

If you’re interested in long distant contacts using low power or have a compromised antenna system like I do, the FT8 mode might be for you.  It’s not really a mode for any kind of ragchew but it is great for very fast QSO exchanges so it will likely be wildly popular for Field Day and contesting.

I found several YouTube videos talking about FT8 and how to setup WSJTX but none were to the point and did not contain the level of detail I wanted to share.  Check out the links below and try FT8 yourself. It works extremely well once you get the hang of it.

~ 73, Jeremy VE7TMY

   18-03

References:

http://www.physics.princeton.edu/pulsar/K1JT/FT8_Operating_Tips.pdf

http://www.arrl.org/news/ft8-mode-is-latest-bright-shiny-object-in-amateur-radio-digital-world

https://physics.princeton.edu/pulsar/k1jt/wsjtx.html

https://www.facebook.com/groups/FT8.Digital.Mode/

More About Antennas, And How To Hide From Apartment Managers

Working the world from my apartment balcony

This type of antenna works well mounted horizontally or vertically, high as a dipole or low as an NVIS antenna for emergency use. -Ed.

Last time, I told you of my costly experiences trying to install an antenna on my 3rd floor apartment balcony. Like many people, I live with antenna restrictions and the management of most complexes have rules regarding what can and can not be placed on the patio. My apartment management is no exception. 

In the previous article, I mentioned the high cost of antennas that claimed super abilities but failed to perform as claimed. I now know, to my cost, that a long wire antenna is about the best you can get but not apartment patio friendly. During one of my recent searches on the Internet for an antenna that would work at my apartment, I found an item about a fellow that was using two reasonably affordable car antennas assembled as a center fed dipole. At the next Saturday morning coffee meeting, I mentioned it to one of the other club members. Low and behold, he mentioned that he had built one using ‘HamStick’ antennas for camping and RV'ing and it performed in a very satisfactory manner. 

When taken apart, which takes only a few minutes, it is very light and very portable. He mentioned that he was not, at the moment, using it. "Would you like to borrow it for a while?" As this was my first opportunity to 'Try before I buy' I jumped at the chance and arrangements were made to pick up the antenna at his earliest convenience. I arrived home at about mid day and was soon out on the patio deck fixing the mount to my portable mast. The mount has two studs instead of the usual one. One stud is the type that grounds itself to the mount and the other faces in the opposite direction and is of the usual coax connector type. The antennas themselves are the MFJ HamStick types, a 48” fiber glass rod wound with the appropriate wire coil for the band you wish to work. They are available for the common Ham bands, and in my case, it was wound for 20 meters. There is a 48” wire whip (sometimes called a 'stinger') that is inserted into the end of the fiber glass rod and is moved in or out to tune the SWR of the frequency you are using. My friend had very conveniently marked the spot to where the two whips should be inserted, which made it very easy for me to get things up and running. I soon realized that a horizontal dipole can be rotated just like a beam antenna, My patio is about 12 feet wide and the assembled antenna is about 16 feet long so only 4 feet of the second whip extends from the end of my patio. My patio faces East so I rotated the antenna to face about South of East.

Since a dipole is Balanced and Coax is Unbalanced, a 1 to 1 Current Balun should be used at the antenna end of the coax or RF will migrate down the Coax braid and could cause painful RF burns to the hands or fingers and create havoc with Computers, TVs and other electronic gear in the room.

I soon had the Coax connected to my radio and I found that the SWR was no more than 1.5 to 1 across the 20 Meter band. With little hope of success, I turned on my radio and started to tune up the 20 Meter band. Suddenly, my speaker loudly announced a CQ call. The caller informed those he hoped were listening that he was located 25 miles North of Cincinnati in the State of Ohio. I answered his CQ call but to my disappointment, he answered another caller. I looked at my power output and found that it was set at only 50 Watts. I hurriedly increased to 100 Watts, to be ready for my next call. Again, to my surprise before I could repeat my call, he said, “I now have VA7FMR” so he had heard me after all, on only 50 Watts. He was not calling in a contest so we had a great chin wag and he was very surprised that I had called on a whip dipole with only 50 Watts. My next contact was a CQer in Hawaii. 

So, for about $150 Canadian you too can have a great dipole Antenna on your Patio that you can rotate as much as your patio permits and no one will notice. I have been using this antenna now for about 2.5 weeks and I have spoken to the apartment manager and he has not mentioned that he had even noticed the antenna. None of my neighbors have mentioned it, nor have they made any complaints. Since you already have the mount and other gear, all you need to change bands is another two stick antennas for say 40 or 80 , meters and it would only take a few minutes to change bands. I have an antenna tuner so I thought that I would try 10 meters and it worked like a charm. I then tried the antenna tuner on the 40 meter band, again with great success. When you are tuning the antenna, tune it for the lowest SWR on the center frequency of the band you are working. That should give you a decent SWR all across the band.

In another article I wrote regarding the purchase of equipment and the need for caution when selecting suppliers, you may remember the digital interface that I purchased because it sounded so good on the manufacturers web page and after it was purchased found it impossible to set up because of the lack of information from the manufacturer. His after sale service was equally bad since he provides none and would hang up the telephone if you asked a question about something not covered in his so called manual. I must admit that parts of the above problems were because of my inexperience and lack of knowledge of the setup procedures of software such as MMTTY, N1MM+ and FLDIGI. There are dozens of settings in each of these pieces of software and since they are used together, if you make a mistake in one of them, the whole fandangle does not work. My experience setting up a SignaLink sound card has given me hope that I may yet get that $275 boat anchor working. I have had success using it for CAT control and a degree of success with CW. My next adventure will be integrating MMTTY with FLDIGY and getting digital to work on it. The most difficult part of my entry into the World of Amateur Radio has not been with the radio equipment that I use, it has been the computer software that actually controls the radio and the sound card and the integration of the three, computer, Radio and sound card. Of course, without an antenna, nothing would work. If there is one piece of advise that a greenhorn like myself could pass on to you, it is, “Never give up” I have spent literally days on the internet and gleaned tons of information that has allowed me to improve my knowledge and understanding of many things in this great Hobby of ours. I hope you learn to enjoy it as much as I do!

~Robert VA7FMR   

A DMR Primer

Our meeting presenters say its the way of the future...

A recent SARC meeting featured two guests, Doug Pattengale VE7CQT and Brad Wilson VA7BWX, who have been heavily involved in local Digital Mobile Radio (DMR). They have kindly agreed to share their presentation slides. 

DMR is a limited open digital mobile radio standard defined in the European Telecommunications Standards Institute (ETSI) Standard TS 102 361 and used in commercial products around the world. In the commercial world, DMR, along with P25 phase II and NXDN are the main competitor technologies in achieving 6.25 kHz equivalent bandwidth using the proprietary AMBE+2 vocoder. DMR and P25 II both use two-slot TDMA in a 12.5 kHz channel, while NXDN uses discrete 6.25 kHz channels using frequency division and TETRA uses a four-slot TDMA in a 25 kHz channel.

DMR was designed with three tiers. DMR tiers I and II (conventional) were first published in 2005, and DMR III (Trunked version) was published in 2012, with manufacturers producing products within a few years of each publication.

In our Amateur Radio world, DMS is one of three main digital radio technologies, with iCom D-Star and Yaesu System Fusion as earlier players.

The primary goal of the standard is to specify a digital system with low complexity, low cost and interoperability across brands, so radio communications purchasers are not locked into a proprietary solution. In practice, given the current limited scope of the DMR standard, many vendors have introduced proprietary features that make their product offerings non-interoperable with other brands.

To view or download the presentation, visit:
https://drive.google.com/file/d/1f9U1mXGQ6nOuE_umJCsPSIPiep-LLieD/view?usp=sharing

Our thanks to Doug and Brad for an informative evening.

Internet Security For Amateurs

Yes, we're susceptible to malware with all these new connected gadgets!

At our February 2020 general meeting we had a guest speaker who is an internationally regarded expert on Internet security. For the past 20+ years, Hardeep Mehrotara has worked for the military, law enforcement and news organizations. He has co-
authored several books on critical controls and security benchmarks, and has participated in hacking operations to test system security. Best of all, he is also a Ham operator as VA7HKM.

The discussion points from the presentation covered

• What is cyber security?
• Importance of cyber security in amateur radio
• evolving cyber security threats
• practice basic cyber hygiene

He covered the importance of Ham radio and internet, our modern digital technology, which more and more is connected to the Internet. Many transceivers and their accessories have some type of Internet connection, particularly remotely controlled radios.

Cyber security refers to combination of people, process and technology designed to protect inter-connected networks (e.g. Internet), devices, programs, and data from attack, damage, or inappropriate or unauthorized access. 

Cybersecurity consists of three key pillars:

Importance of cyber security in amateur radio

• Denial of service on ham radio networks.
• Hacking of Software defined radios.
• Malicious control of remote devices.
• Impact on Internet-Of-Things (IoT) devices.

Threat actors

Evolving cyber threats include

• Phishing
• Third party email compromises
• Ransomware
• IoT based attacks

Phishing and Third party compromised email. ARRL warned about this to their members with an xxx.arrl.net forwarding address

Ransomware 

Also a real threat and you should keep a separate backup as a precaution.

Practicing basic cyber hygiene

• AVOID OLDER OPERATING SYSTEMS!  For example, Windows 7 is no longer supported.
• ALL operating systems are at risk, including Mac and Linux
• Install a reputable anti-virus and firewall
• Patch your systems regularly
• Use strong passwords and do not re-use passwords
• Use multi-factor authentication where possible
• Encrypt your sensitive information
• Backup your information
• Be cautious when you click on links on websites, emails, social media

Cyber Threat Predictions

As technology progresses, so will the threat.

See Hardeep on a news presentation on cyber security threats
https://globalnews.ca/video/5974584/protecting-small-businesses-from-cyber-security-threats/ 

The slides of Hardeep's presentation are at:

https://drive.google.com/file/d/1iT93R0G3jCyuJllQ7eGFCek2g6sBQhWC/view?usp=sharing