|Kendall Amateur Radio Society|
Six Meters (50mHz), the Weak Signal World and Digital
It seems the digital world of weak signals is the fastest growing segment of our hobby. Each month that passes sees new operating modes and new software. The purpose of this section is to try as best we can to keep readers aware of what is happening in this segment, to show you examples, and where to find more information.
Rocks a Flying
Dave Moore, N7RF, March & April, 2018.
With yagis up now, I found time on March 18th to check
out the 6 meter meteor calling frequency (50.260). I immediately
started hearing strong bursts of raspy MSK144 signal. I started up
the WSJT-X software and then logged in to the Ping Jockey web site to
see what was happening (https://www.pingjockey.net/cgi-bin/pingtalk).
As it seemed pretty busy, I announced on PJ that I would be calling CQ.
Almost immediately, K8LEE came back. The QSO exchange was rapid
since the meteors were hot and heavy. During the final
"73" exchange, I saw an uncommon 4-1/2 second burst from Wayne
in Indiana. Here's the record of that burst on the 15-s long
waterfall trace. Wow.
After that, I conducted QSO's with KE5RV (Arkansas),
K2DRH (Illinois), and W5TN (Texas). The next morning, I added
WB4JWM (Georgia), and W8BYA (Indiana).
March 24th update: Another good morning for
meteors. I called CQ and was called by two stations, one after the
other, WB4JWM again (Georgia) and K0TPP (Missouri). Several times,
I saw bursts from 2 or 3 stations within the same 15-second frame.
At 1427Z, I worked AK5QR (Alabama), and then was cold-called by XE2YWH.
My first new country on meteor scatter. Jose is 535 miles south of
here in Zacatecas, Mexico. Here's the "Roger" and
"73" transmissions at 1430Z and 1431Z:
And, finally, I asked W5LDA to give it a shot via the
PingJockey web site. We connected within 3 or 4 sequences.
Big signal from Oklahoma City!
March 31 update
I turned on the 6m station this morning and immediately decoded a meteor CQ from XE2JS in Chihuahua (449 miles). After calling him for several minutes, someone broke in on SSB. It was XE2OR in Coahuila, 151 miles away, with a 59+ ground wave signal. After that QSO, I returned to calling XE2JS, and we finally connected. He is my second Mexico QSO on meteor scatter. A few minutes later, I worked N0LL in Kansas (693 miles). I switched over to 2 meters to see what I could see. On 2m, I'm only running 60W barefoot until I get the PTT cable made up for the linear.. The first decodes I received were from XE2AT in Aguascalientes, Mexico (689 miles). I pointed the beam south and, after 10 minutes or so, I worked him, my first 2m meteor QSO (of recent times), and my first 2m DX entity at the same time!
American Meteor Society
Meteor Shower Calendar
activity picks up a bit during April as the Lyrids become active during
the month. They are active from the 14th through the 30th, with a
pronounced maximum on the 22nd. Sporadic rates during April are steady as
seen from both hemispheres with southern observers enjoying twice the
activity that can be seen from the mid-northern hemisphere.
this period the moon will reach it’s full phase on Saturday March 31. At
that time it will be located opposite the sun and will remain above the
horizon all night long. As the week progresses the waning gibbous moon
will rise later in the evening but will still hamper the more active
morning hours making meteor observing difficult at best. The estimated
total hourly meteor rates for evening observers this week is 2 as seen
from mid-northern latitude (45N) and 4 from the southern tropics (25S).
For morning observers the estimated total hourly rates should be near 5 as
seen from mid-northern latitudes (45N) and 8 from the southern tropics
(25S). The actual rates will also depend on factors such as personal light
and motion perception, local weather conditions, alertness and experience
in watching meteor activity. Rates are reduced during this period due to
interfering moonlight. Note that the hourly rates listed below are
estimates as viewed from dark sky sites away from urban light sources.
Observers viewing from urban areas will see less activity as only the
brighter meteors will be visible from such locations.
radiant (the area of the sky where meteors appear to shoot from) positions
and rates listed below are exact for Saturday night/Sunday morning March
31/April 1. These positions do not change greatly day to day so the listed
coordinates may be used during this entire period. Most star atlases
(available at science stores and planetariums) will provide maps with grid
lines of the celestial coordinates so that you may find out exactly where
these positions are located in the sky. A planisphere or computer
planetarium program is also useful in showing the sky at any time of night
on any date of the year. Activity from each radiant is best seen when it
is positioned highest in the sky, either due north or south along the
meridian, depending on your latitude. It must be remembered that meteor
activity is rarely seen at the radiant position. Rather they shoot
outwards from the radiant so it is best to center your field of view so
that the radiant lies near the edge and not the center. Viewing there will
allow you to easily trace the path of each meteor back to the radiant (if
it is a shower member) or in another direction if it is a sporadic. Meteor
activity is not seen from radiants that are located far below the horizon.
The positions below are listed in a west to east manner in order of right
ascension (celestial longitude). The positions listed first are located
further west therefore are accessible earlier in the night while those
listed further down the list rise later in the night.
sources of meteoric activity are expected to be active this week.
Details of each
source will continue next week when lunar interference will be much less.
FT8 Digital Mode
Dave Moore, N7RF, March, 2018
On a separate note, I have worked quite a bit of DX on
FT8. To me, it seems a lot easier than fighting the CW and SSB
pileups you hear when a rare one comes on. It's hard to compete
with the super stations with multiple towers, stacked beams on every
band, and full legal limit amplifiers. There is a distinct
advantage when the DX station can pull your weak signal out of the noise
and get a perfect copy in the presence of lots of other stations.
Software has now replaced the human ear. Yeah, it almost sounds
like cheating, but you can't look at it that way. Technology keeps
improving the hobby. I bet very few of you run vacuum tube radios
anymore, nor are most of your solid state rigs without modern Digital
Signal Processing. Think of it this way: instead of aspiring
to be like the muscle stations and overpower everyone on frequency, you
don't need to any more. IMHO, this opens up the door for many,
many more hams to make more contacts rapidly without the mega-buck
Nevertheless, as the popularity of FT8 grows, we are
starting to see DX pileups. The problem is, you can have dozens of
signals spread across the 2 kHz wide FT8 channel and the software
decodes and displays all of them every 15 seconds. A DX station
sees all the stations calling him but the software only lets you respond
to one station at a time. Until now. The ARRL reported that
a beta version of a new FT-8 contest mode software was tested recently.
A DX station (the Fox) can now conduct multiple QSOs simultaneously.
Fox can select the number of responses (Hound stations) he wants to deal
with. He can also call region-selective CQs. When Fox
responds, his transmission consists of multiple simultaneous signals
sent to selected Hound stations, each on their own frequency.
Sounds crazy. And it's not simple. Users are encouraged to
study the operating guide and not try to wing it (http://physics.princeton.edu/pulsar/k1jt/FT8_DXpedition_Mode.pdf
). Contest mode will never be used in established FT8 channels,
rather a specific frequency to be announced beforehand. On 20m, the FT8
channel is 14.074-14.076 MHz. During the recent beta test of
contest mode, they used 14.105 MHz. The test results were
positive. Expect to see this used by real DXpeditions. But
get some some conventional FT8 time in before you try it.