30 Jun 2017

New Digital Mode from K1JT

Just got this from Bob G3WKW:
Steve (K9AN) and I have developed a potential new mode for WSJT-X. We're calling the mode "FT8" (Franke-Taylor design, 8-FSK modulation). FT8 is designed for situations like multi-hop Es where signals may be weak and fading, openings may be short, and you want fast completion of reliable, confirmable QSOs.
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, keying rate = tone spacing = 5.86 Hz
  - Waveform: Continuous phase, constant envelope
  - Occupied bandwidth: 47 Hz
  - Synchronization: three 7x7 Costas arrays (start, middle, end of Tx)
  - Transmission duration: 79*2048/12000 = 13.48 s
  - Decoding threshold: -20 dB (perhaps -24 dB with AP decoding, TBD)
  - Operational behavior: similar to HF usage of JT9, JT65
  - Multi-decoder: finds and decodes all FT8 signals in passband
  - Auto-sequencing after manual start of QSO
*Comparison with slow modes JT9, JT65, QRA64:*  FT8 is a few dB less sensitive but allows completion of QSOs four times faster.  Bandwidth is greater than JT9, but about 1/4 of JT65A and less than 1/2 QRA64.
*Comparison with fast modes JT9E-H:*  FT8 is significantly more sensitive, has much smaller bandwidth, uses the vertical waterfall, and offers multi-decoding over the full displayed passband.
*Still to come, not yet implemented:*  We plan to implement signal subtraction, two-pass decoding, and use of "a priori" (already known) information as it accumulates during a QSO.
Three extra bits are available in the message payload, with uses yet tobe defined.  We  have in mind special message formats that might be used in contests, and the like.  Your considered suggestions for use of these bits are very welcome!
K1JT, K9AN, and G4WJS have conducted on-the-air tests of FT8 with excellent results.  We're now at a stage where tests under a wider range of conditions are desirable.  If you can build WSJT-X from source code revision r7750 or later, and would like to help, please do so and report your results to us!  Pre-built installation packages will be made available after further testing is completed.
Suggestions for FT8 setup and examples of use can be found in a screen shot posted here: http://physics.princeton.edu/pulsar/k1jt/ft8.png
We look forward to receiving your feedback.
   -- 73, Joe, K1JT

It will help to have some initial frequency coordination among those
testing the new FT8 mode in WSJT-X v1.7.1.

To help get things started, we suggest using the following frequencies:

Band    MHz
-------------
 160   1.841
  80   3.579
  40   7.079
  30  10.141
  20  14.079
  17  18.105
  15  21.079
  12  24.920
  10  28.079
   6  50.313
   4  70.094
-------------

Most of these suggestions follow a simple guideline: add 3 kHz to the
commonly used JT65 dial frequency.

For 6 meters we suggest using 50.313, which should be consistent with
band plans in all IARU Regions.  (Six meter activity that's now on
50.276, world-wide, might be moved to 50.310.)

We are very much open to suggestions for changes in the above table.

   -- 73, Joe, K1JT

Friedrichshafen

This large German rally is really an international affair attracting visitors from all over Europe and beyond. As little new was announced at Dayton, USA by the big Japanese companies, it is unlikely we'll see anything new announced in Europe, but I have been wrong. It would be nice to be surprised.

As far as I know, it is the biggest rally in Europe. It is too far for me.

The rally is just a few weeks away.

See http://www.hamradio-friedrichshafen.de/ham-en/

Sunspots and 10m - Friday June 30th 2017

Solar flux is 71 today and the sunspot number is 12. A=5 and K=1.

29 Jun 2017

Back to 6m JT65

After a few hours on 10m JT65 (no spots), I have returned to 6m JT65 - no spots yet.

UPDATE 2050z: GI4SNA (488km) is the best DX on RX so far on 6m JT65. G0HOF (45km) is the best on TX (1W ERP).

UPDATE 2200z: M1BXF (14km) is also spotting me. No Es here now on 6m JT65. I shall probably go QRT soon until breakfast.

Now on 10m JT65

For a change, I am now on 10m JT65 (2.5W). So far, nothing on RX or TX.

G0PQO contacted me to say I'd been calling him for 5 hours on 6m JT65, and I said I had not been. Then I found out that, in error, I had been, so I had to eat humble pie! Sometimes I am really stupid.

More 6m JT65 "DX"

Yet again this morning, I am supposed to have copied another Indonesian on 6m JT65 at not far short of 12000km. Yet again, this is surely a pirate and I have discounted this as a real spot. If true, it would be noteworthy. As a pirate - just sad.

Rallies this Saturday

1 JULY 2017 : BANGOR & DISTRICT ARS ANNUAL RALLY
Donaghadee Community Centre, Parade, Donaghadee BT21 0HB Doors open at 11.30am. There will be trade stands, a Bring & Buy and an RSGB bookstall. Catering is available on site. A raffle will be held on the day. Contact: Harry Squance, GI4JTF on 0777 594 2174 or by email to gi4jtf@gmail.com.

1 JULY 2017 : 1st HOUGHTON LE SPRING ARC RALLY
The Dubmire Royal British Legion Club, Britannia Terrace, Fencehouses DH4 6LJ Doors open 10.30am until 3pm. Entry is free. There will be traders, club and private stands. Table space is limited (and free) and will be allocated on a first come first served basis. Tea & coffee will be available and a licensed bar from 11am. Details from Ken, M6ELL by email m6ellken@aol.com or on 0795 146 0290.

A list of rallies can be found at http://rsgb.org/main/news/rallies/

OFCOM

Usually, I get an email from OFCOM, but I seem to have missed the latest. I expect this is human error or, more probably, a computer error. I get pretty annoyed with computer generated emails. Lately I have received these from Direct Line, Barclays, British Gas and OFCOM to name just a few. You just know no human was involved.

Anyway, enough moaning, and back to OFCOM. This is the latest statement about enforcement.

See https://www.ofcom.org.uk/consultations-and-statements/category-2/ofcoms-approach-to-enforcement

Waffle, more waffle, and basically unless money is involved go away as we are unlikely to help you. Sorry, but bring back the GPO man who understood radio and really tried to help. Basically OFCOM is, for the radio amateur, a waste of time. Run by headless chickens, it would seem, who have no real knowledge of radio. That is my personal experience and I accept others may have had a better experience.  Sadly OFCOM comes across as a QUANGO trying hard to justify why it is there. My personal view is scrap it. Unless it employs people who really understand radio, they have no hope of doing a useful job.

Bitter and twisted? Me?

Active on 10m WSPR TX and 6m JT65 transceive

At the moment I am on 10m WSPR TX (500mW) and 6m JT65 transceive (1W ERP). I may change bands and modes later.

Sunspots and 10m - Thursday June 29th 2017

Solar flux is 71 today and the sunspot number 13. A=4 and K=2.

There was a little 10m Es earlier when my 500mW WSPR was spotted in Italy.