Kendall Amateur Radio Society

KB5TX


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, 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!

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 expense.

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.

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