FT8 Archive

Outreach

Why the Hate for FT8?

You have to grow with the times or the times will outgrow you.

That is how my Music Director would sign off from his afternoon radio show back in the early 70’s when I was Program Director at an AM radio station.

I never would have imagined in 1956 when I was introduced to Amateur Radio that one day as I left a doctor’s appointment in 2024, I could carry a Ham Radio station in a small backpack and ride my bicycle less than a mile to a Parks on the Air site and communicate to other operators around the world. The only way I would have believed that back in 1956; is if I were sitting with Marty McFly in a Delorean and a plutonium-powered nuclear fission reactor with a Flex Capacitor traveling ay 88 MPH and set the date for March 14, 2024.

You might wonder as why I mentioned my introduction to Ham Radio in 1956 and FT8 today. Well, in the early 1950’s I remember Ice Boxes, not refrigerators. Ice Boxes. Several times a week The Ice Man riding in his mule drawn cart would stop by my neighbor and drop off a large cube of ice for their Ice Box to keep their perishables fresh. It wasn’t too long in the mid 1950’s my neighbor purchased a refrigerator made at GE’s Louisville’s Appliance Park.

Technical

Bicycle Mobile on the HF Bands (QST)

In his Bicycle Mobile on the HF Bands article (a free preview from the August 2020 issue of QST Magazine), Christian Bravo, W4ALF, discusses “an easy way to implement a mobile radio system, for the operator on two wheels.” 1

After experimenting with pedestrian mobile and being active with Summits on the Air (SOTA), I was looking for a new amateur radio challenge. My experiences with portable ham gear led me to the idea of adapting my mobile setup to fit on my bicycle. The two-wheel setup would allow me to be even more mobile, and still be able to communicate on the HF bands. 1

W4ALF’s article covers:

  • The Radio Setup
  • The Bike
  • Mounting the Antenna
  • Performance

The Mounting the Antenna section of the article goes into detail about W4ALF’s tapped coil shortened vertical antenna with a raised counterpoise, including a description of the Buddipole pieces used for the vertical.

In closing, W4ALF states:

Operating bicycle mobile is a fun way to get out and operate while getting some exercise. Gear today lends itself well to having a high-performing HF setup on the go with two wheels. My antenna system allows for more bands and radials while operating stopped at a location without having to hang antennas. I hope the ideas presented here spark your own mobile adventures and homebrew modifications. 1

  1. “Bicycle Mobile on the HF Bands”, ARRL The national association for Amateur Radio, retrieved July 8 2020, http://www.arrl.org/files/file/QST/This%20Month%20in%20QST/August2020/BRAVO!.pdf. ↩︎ ↩︎ ↩︎

Technical

Build The Wouff Hang

An important part of hanging an antenna from a tree is a bearing, or pulley, to eliminate guy line friction and facilitate antenna repairs and adjustments.

The Wouff Hang—whimsically named after the infamous Wouff Hong from Amateur Radio history—is an easy to build bearing made from common PVC water pipe or electrical conduit found at any hardware or home supply store.

Author Roy Lewallen, W7EL, describes construction and use of The Wouff Hang in a well illustrated article which is (a free preview from the October 2019 issue of QST Magazine).

About the author

Roy Lewallen, W7EL, is the creator of the popular antenna-modeling software, EZNEC , and the author of many articles on ham radio-related projects. He was inducted into the Royal Order of the Wouff Hong at the ARRL National Convention in Seattle in 1980. While Roy has been hanging antennas since before getting his Novice license in 1957, this [article] is his first attempt at merging what he learned from those experiences.1

  1. “The Wouff Hang”, ARRL The national association for Amateur Radio, retrieved September 17 2019, http://www.arrl.org/files/file/QST/This%20Month%20in%20QST/October2019/Lewallen.pdf. ↩︎

Technical

Enjoy FT8 From Almost Anywhere

Having the ability to experiment with operating your equipment in new ways is an aspect of Amateur Radio which sets our hobby apart from radio services such as CBRS, GMRS, FRS, and MURS.

In his Enjoy FT8 From Almost Anywhere article (a free preview from the August 2019 issue of QST Magazine), J. Robert Witmer, W3RW, writes:

Imagine hunting 6-meter DX at a restaurant while eating breakfast, or making an all-time new DX contact while waiting for a flight. I’ve found myself operating remotely in these types of situations, and many others, using nothing more than my smart phone. If you think this type of operating is complicated and expensive, prepare to be surprised!1

W3RW goes on to describe his approach to remote FT8 operation which combines WSJT-X and TeamViewer with his radio, shack computer, and a mobile / portable device.

His article covers installation and configuration of WSJT-X and TeamViewer at your station and of TeamViewer on your mobile / portable device.

W3RW then discusses:

  • Single Band Operation
  • Multiband Remote Operation
  • Other Considerations

W3RW reminds Amateur Radio Operators to enable the “watch-dog timer” in the WSJT-X software on their station computer to prevent run-away operation. And to enable their transceiver’s “watch-dog” feature if it has one.

In closing, W3RW states:

By combining WSJT-X FT8 operation with a remote desktop control program such as TeamViewer , you can add an exciting new dimension to operating. Operating remotely during breaks in the action while participating in other events can be a great way to catch elusive band openings and hopefully work a new one!

If you’re not a fan of FT8, the TeamViewer approach described here can be used to remotely control other station computer applications.1

  1. “Enjoy FT8 From Almost Anywhere”, ARRL The national association for Amateur Radio, retrieved August 24 2019, http://www.arrl.org/files/file/QST/This%20Month%20in%20QST/September2019/Witmer.pdf. ↩︎ ↩︎

Technical

WSJT-X 2.0 Will Be a Mandatory Update

ARRL, The national association for Amateur Radio, reports that Significant Changes [are] in Store for FT8 and MSK144 with WSJT-X Version 2.0:

WSJT-X co-developer Joe Taylor, K1JT, has announced that major changes are coming to the FT8 and MSK144 digital protocols when WSJT-X version 2.0 arrives in a few months. Taylor said version 2.0 should be ready for prime time by January.

The “Significant Changes” article lists a potential WSJX-X 2.0 features—including ARRL Field Day operation with standard Field Day exchanges and A special telemetry message format for exchanging arbitrary information up to 71 bits—which, according to K1JT, will “work seamlessly and automatically … No contest mode checkboxes are needed”.1

These new features will not be backwards compatible. “It will be essential for users to upgrade to version 2.0 in order to use the new features and communicate with others who have made the upgrade.”2

  1. “Significant Changes in Store for FT8 and MSK144 with WSJT-X Version 2.0”, ARRL The national association for Amateur Radio, retrieved July 27 2018, http://www.arrl.org/news/significant-changes-in-store-for-ft8-and-msk144-with-wsjt-x-version-2-0. ↩︎

  2. “Significant Changes in Store for FT8 and MSK144 with WSJT-X Version 2.0”, ARRL The national association for Amateur Radio, retrieved July 27 2018, http://www.arrl.org/news/significant-changes-in-store-for-ft8-and-msk144-with-wsjt-x-version-2-0. ↩︎

Technical

Introduction to WSJT-X FT8

FT8 is a new mode included in WSJT-X versions 1.8 and later.

This weak signal mode is intended—and optimised—for making efficient barebones contacts; a definite plus during this time of poor propagation. Although FT8 does not support rag-chewing or contesting exchanges it is, none the less, well worth trying out in the Amateur Radio spirit of learning and experimentation.

The slides from my presentation after the adjournment of the April 17, 2018, RRRA Business Meeting are available for download from the Training and Education | Presentations folder on the RRRA Groupware Server.

About FT8

The new mode is named after its developers, Steven Franke, K9AN, and Joe Taylor, K1JT. The numeral designates the mode’s 8-frequency shift keying format. Tones are spaced at 6.25 Hz, and an FT8 signal occupies just 50 Hz. Unlike JT65 or JT9, transmit and receive cycles in FT8 each last about 15 seconds. Like JT65, FT8 requires accurate time synchronization. An auto-sequencing feature offers the option to respond automatically to the first decoded reply to your CQ.

“FT8 is an excellent mode for HF DXing and for situations like multi-hop Es on 6 meters, where deep QSB may make fast and reliable completion of QSOs desirable,” Taylor’s release notes assert. 1

  1. “FT8 Mode is Latest Bright Shiny Object in Amateur Radio Digital World”, ARRL The national association for Amateur Radio, retrieved April 18 2018, http://www.arrl.org/news/ft8-mode-is-latest-bright-shiny-object-in-amateur-radio-digital-world. ↩︎

Education

FT8 Presentation at April Club Meeting

All Hams interested in FT8 are encouraged to attend KA0LDG’s presentation about this mode at the April RRRA Club Meeting

KA0LDG is planning to present a Power Point briefing about FT8 followed by a live demonstration of the mode using his portable station.

Please direct all questions about this upcoming presentation to .

Technical

New FT8 Mode included in WSJT-X Beta Release

WSJT-X version 1.8.0 includes a new mode named FT8

This mode features:

  • QSOs 4 times faster than JT65 or JT9
  • Sensitivity down to -20 dB on the AWGN channel
  • Auto-sequencing includes an option to respond automatically to first decoded reply to your CQ

WSJT-X source code; along with installation packages for Windows, Linux, OS X, and Raspbian; is available for download at http://physics.princeton.edu/pulsar/K1JT/wsjtx.html

About the FT8 protocol

WSJT-X Version 1.8.0 includes a new mode called FT8, developed by K9AN and K1JT. The mode name “FT8” stands for “Franke and Taylor, 8-FSK modulation”. FT8 uses 15-second T/R sequences, provides 50% or better decoding probability down to -20 dB on an AWGN channel, and maintains good performance on Doppler-spread fading channels. An auto-sequencing facility includes an option to respond automatically to the first decoded reply to your CQ. FT8 QSOs are 4 times faster than those made with JT65 or JT9. FT8 is an excellent mode for HF DXing and for situations like multi-hop E_s on 6 meters, where deep QSB may make fast and reliable completion of QSOs desirable. [ 1 ]

Some important characteristics of FT8:

  • T/R sequence length: 15 s
  • Message length: 75 bits + 12-bit CRC
  • FEC code: LDPC(174,87)
  • Modulation: 8-FSK, tone spacing 6.25 Hz
  • Constant-envelope waveform
  • Occupied bandwidth: 50 Hz
  • Synchronization: 7x7 Costas arrays at start, middle, and end
  • Transmission duration: 12.64 s
  • Decoding threshold: -20 dB; several dB lower with AP decoding
  • Multi-decoder finds and decodes all FT8 signals in passband
  • Optional auto-sequencing and auto-reply to a CQ response
  • Operational behavior similar to JT9, JT65

Footnotes

[ 1 ] “WSJT-X Release Notes”, Joe Taylor K1JT, retrieved July 18 2017, https://physics.princeton.edu/pulsar/k1jt/Release_Notes_1.8.0.txt.