Ham Radio News
…because we don’t live in a vacuum
WSJT-X Version 2.2.0 is Now in
General Release
WSJT-X version 2.2.0 is now in general availability release, after a
short period in beta (or release candidate) status. WSJT-X
version 2.2 offers 10 different protocols or modes -- FT4, FT8,
JT4, JT9, JT65, QRA64, ISCAT, MSK144, WSPR, and Echo. The first
six are designed for reliable contacts under weak-signal
conditions, and they use nearly identical message structure and
source encoding. JT65 and QRA64 were designed for EME
("moonbounce") on VHF/UHF bands, but have also proven very
effective for worldwide very low-power communication on HF
bands.
"FT8 is operationally similar but four times faster (15-second T/R
[transmit-receive] sequences) and less sensitive by a few
decibels," developer Joe Taylor, K1JT, explains in the version
2.2.0 User Guide. "FT4 is faster still (7.5-second T/R sequences)
and especially well suited for contesting."
Taylor noted that even with their shorter transmit-receive
sequences, FT4 and FT8 are considered "slow modes," because
their message frames are sent only once per transmission. "All
fast modes in WSJT-X send their message frames repeatedly, as
many times as will fit into the [transmit] sequence length," he
explained.
Compared with FT8, FT4 is 3.5 dB less sensitive and requires 1.6
times the bandwidth, but it offers the potential for twice the
contact rate.
New in WSJT-X version 2.2.0: FT8 decoding is now spread over
three intervals, the first starting at 11.8 seconds into a receive
sequence and typically yielding around 85% of the possible
decodes. This means users see most decodes much sooner
than with previous versions. A second processing step starts at
13.5 seconds, and a third at 14.7 seconds.
"Overall decoding yield on crowded bands is improved by 10%
or more," Taylor said.
Other changes: Signal-to-noise (SNR) estimates no longer
saturate at +20 dB, and large signals in the passband no longer
cause the SNR of weaker signals to be biased low. Times written
to the ALL.TXT cumulative journal file are now correct, even
when decoding occurs after the T/R sequence boundary.
-ARRL Letter
Social Distancing Exam Sessions
Demonstrate Pent-Up Demand for
Testing
A recent in-person "social-distancing" amateur radio exam
session in Indiana and a "drive-in" session in California are
representative of those that are relieving some of the pent-up
demand for testing. As the COVID-19 pandemic continues, in-
person exam sessions have begun to resume across the US and
elsewhere in the world.
"With in-person sessions starting up again around the country,
we are hearing the same story from volunteer examiner (VE)
teams everywhere," said ARRL Volunteer Examiner Coordinator
(VEC) Maria Somma, AB1FM. "Large numbers of candidates who
have been waiting to test are contacting teams and are thankful
for the opportunity to sit for an exam. So far, we've heard
mostly positive results. Candidates are very prepared, as they've
had extra time to study. VE teams and candidates are following
CDC and state guidelines for social distancing."
Anderson (IN) Repeater Club VE Team Liaison Steve Riley,
WA9CWE, told ARRL earlier this month that his club has been
conducting test sessions every month since 2011, typically
serving four or five candidates each session, but the May 19
session attracted 14 individuals.
"We were unable to test in April, but were able to get back in for
the May session," Riley said. "Several candidates were from
Central Indiana, and we had a fellow drive down from Chicago, a
couple from the Dayton, Ohio, area, and also from Fort Wayne,
Indiana." The team limited participation until it could conduct
the trial run.
VEs and examinees alike wore face masks, and the test room
was configured to accommodate the necessary spacing
between individuals. "We questioned everyone entering with
the usual health questions," he added.
"Our VE paperwork became a serial flow for grading instead of
our prior 'huddle' of the three VEs over the answer sheet," Riley
recounted. "As a result, things were a bit slower than in the past.
The tables, pencils, and pens were disinfected."
The result for the session was 11 new radio amateurs and three
upgrades. "All went well, although we identified a couple
improvements in paperwork flow for next month's test," Riley
added.
"There is quite a pent-up demand for new amateur licenses and
upgrades as a result of the number of test sessions that have
been canceled," he continued. "I hope that as sessions resume,
they have the success that we had." Riley said he's already been
contacted by six people who plan to sit for the exam in June.
In California, VE Larry Loomer, KI6LNB, told the ARRL VEC that
his team conducted a successful drive-in license testing session
on May 16 at the Concord Bay Area Rapid Transit Station.
Loomer explained that candidates fill out their paperwork in
their cars. "I have circled in pencil all of the boxes on [Form]
605, the answer sheet, and the CSCE (Certificate of Successful
Completion of Exam) that the candidates need to fill in, to
minimize the face-to-face time." Once paperwork is completed,
candidates take a test booklet and answer sheet on a clipboard
and sit in a chair in front of their cars, taking the test in front of
the VEs.
Completed tests go into a box on the VE table, and candidates
back their cars into a holding area, to let other cars park by the
testing chairs. Once a test is scored and signed, the CSCE goes
to the waiting candidate, who may then drive away.
"I'm seeing videos of remote test-taking sessions, and they still
look labor intensive to me," Loomer said. "We are sticking with
the drive-in format for the present time."
Somma said, "Our VE teams are doing a great job! I'm
impressed with their attention to safety, their professionalism,
and their innovative tactics."
-ARRL Letter
Six Meters Recently Running Hot
In recent days, 6 meters has been living up to its nickname -- "the magic band."
On May 30 at around 1200 UTC, Rich Zwirko, K1HTV, in Virginia, worked Nicolas
Sinieokoff, TT8SN, in Chad, who answered his CQ on FT8. After the quick
exchange, K1HTV alerted several local 6-meter DXers, who were also able to
snag the rare contact. TT8SN was able to work into the US mid-Atlantic and
Arkansas as well as West Virginia on FT8 before switching to CW at about 1300
UTC and then alternating between the two modes over the next hour. Yves
Collet, 6W1TA, in Senegal also showed up on the band, and K1HTV and other
stations were able to put him in the log as well.
"So the 6-meter E-skip season has begun," Zwirko remarked. "Who knows what
kind of magic the band will serve up?"
What's being called a historic opening on 6 meters occurred on May 31, when
David Schaller, W7FN, in the Pacific Northwest saw the band open at about 1430
UTC and stay open for a couple of hours. W7FN worked 12 DXCC entities on FT8
(on 50.323 MHz); other stations had similar success. Schaller said longtime 6-
meter DXers from his area reported never having experienced a 6-meter
opening to Europe like the one on May 30.
On May 28, Bill Steffey, NY9H, just south of Pittsburgh in western Pennsylvania,
reported working three European stations on FT8 at around 2200 UTC. "Six
[meters] has been great this week," Steve Fetter, WA8UEG, in eastern
Pennsylvania, observed after working stations in the Caribbean and in Europe.
From Greenland, Bo Christensen, OX3LX, has been showing up on 6 meters on
FT8 between 2230 and 0000 UTC. He's been reported working into the mid-
Atlantic stations with a good signal. Mark Murray, W2OR, in Florida, took
advantage of an opening to Japan on the evening of May 22. Two Florida
stations each worked 20 or more Japanese stations, and one was said to have
had 40 stations in Japan. W2OR said it was "an incredible number for an opening
that did not last." On the previous evening, a similar opening occurred from
Wisconsin and other parts of the upper midwest.
Jim Reisert, AD1C, reported that stations in Wisconsin and Minnesota were able
to work Hawaii on 6 meters starting around 2300 UTC on May 24, using FT8.
John Sweeney, K9EL, in Illinois, worked three Hawaiian stations from 2240 - 2250
UTC. He called it "the best 6-meter opening to Hawaii from W9 that I have seen."
Kev Hewitt, ZB2GI, in Gibraltar, made his first 6-meter contact of the season,
working K1TOL, in Maine. ZB2GI said the band sounded dead, except for
K1TOL's signal.
-ARRL Letter
Moonbounce Contact via FT8 Could be a
First
FT8 codeveloper Joe Taylor, K1JT, has reported what is possibly the first FT8
contact via moonbouce (Earth-Moon-Earth or EME) on May 21 between Paul
Andrews, W2HRO, in New York, and Peter Gouweleeuw, PA2V, in the
Netherlands. The contact was made possible using the currently available beta-
release candidate of WSJT-X, version 2.2-rc1.
"Why might you want to use FT8 instead of 'Old Reliable JT65' for EME QSOs?"
Taylor asked in a subsequent Moon-Net post. "FT8 is about 4 dB less sensitive
than JT65, but with 15-second T/R [transmit/receive] sequences it's four times
faster, and it doesn't use Deep Search," he said, answering his own question.
The FT8 protocol included in the beta version of WSJT-X has an optional user
setting to work around the 2.5-second path delay. "For terrestrial use, the FT8
decoder searches over the range -2.5 to +2.4 seconds for clock offset DT
between transmitting and receiving stations," Taylor explained. "DT" represents
the difference between the transmission time and actual time. "When 'Decode
after EME delay' is checked on the WSJT-X 'Settings' screen, the accessible DT
range becomes -0.5 to +4.4 seconds. Just right for EME."
As Taylor explained in his post, FT8 uses 8-GFSK modulation with tones
separated by 6.25 Hz. At the time of the contact, the expected Doppler spread
on the W2HRO - PA2V EME path was 8 Hz, which would cause some additional
loss in sensitivity. Despite the path losses, however, copy between W2HRO and
PA2V was "solid in both directions," Taylor said.
Taylor said that when he was active in EME contests on 144 MHz, he was always
frustrated that, even with reasonably strong signals, the maximum JT65 contact
rate is about 12 per hour. "With FT8, you can do 40 per hour, as long as
workable stations are available," he said.
As for using FT8 for EME contacts on 1296 MHz, Taylor said it "might sometimes
work, but Doppler spread will probably make standard FT8 a problem." Given
sufficient interest, however, he said the WSJT-X development team could design
an FT8B or FT8C with wider tone spacing. He encouraged the use of FT8 for
moonbounce on 144, 432, and 1296 MHz and asked users to report their results
to the development team.
"A 'slow FT8' mode is indeed a sensitivity winner on suitable propagation paths,"
he said in a later Moon-Net post. "We are busy implementing such a mode, but
with particular emphasis on its use on the LF and MF bands."
Taylor said FT8 has the operational advantage of putting all users in one (or a
few) narrow spectral slices on each band. "So, it's easy to find QSO partners
without skeds or chat rooms," he said. "Everything is done over the air, with no
'side channels' needed."
Taylor also remarked in response to posts from those who, like him, "love CW."
"I agree it's a thrill to hear your own lunar echo, and to make CW EME QSOs," he
said. "Sometimes I pine for the bygone world of commercial sailing ships, which
happen to be very much a part of my family's history," Taylor concluded. "But I
know that technologies evolve, and the world does not stand still."
- ARRL Letter
Hytera filed for Chapter 11 bankruptcy
Citing ongoing lawsuits brought by Motorola Solutions and the impact of the
COVID-19 pandemic the company said that it plans to use the Chapter 11
restructuring process to address the issues caused by those two events.
“Nearly 20 years ago, Hytera began partnering with American dealers and
bringing the most innovative and valuable LMR solutions to the market, while
constantly seeking to improve support and service to our dealers and
customers,” Hytera America President Alla Huang said in a statement. “We
remain committed to our tradition of excellence and are confident in our
sustainable growth for the future. We look forward to introducing our new
product lines such as Hytera HALO nationwide group communications, a total
solution of PoC (push-to-talk over cellular) hardware, software and cloud
services, as well as facial recognition and temperature-measuring integrated
access control solution and next-generation Digital Mobile Radio (DMR).”
Additionally, Hytera said that it is working with it dealers to help first responders
and medical organizations combat the ongoing coronavirus pandemic. During
the past few months, Hytera has donated two-way radios to multiple hospitals
in cities such as New York.
In its voluntary petition for bankruptcy, Hytera America estimated that it has
1,000 – 5,000 creditors, and estimated that it had $10 million – $50 million in
assets against $500 million – $1 billion in liabilities. A large portion of the
liabilities includes legal damages owed to Motorola Solutions.
In February, a jury for the U.S. District Court for the Northern District of Illinois
awarded Motorola $764.6 million in damages. The damages to Motorola are the
single largest claim on the petition. The next largest claim is for $620,231 to SAF
Tehnika, which is listed as a trade debt. Most of the other outstanding claims are
trade debts to various companies ranging from $3,000 – $120,000.
- Danny Ramey, Radioresource