New versions K1JT weak signal digital modes

Bob, G3WKW, has passed on this information from Joe Taylor K1JT:

"Date: Fri, 07 Aug 2015 16:28:19 -0400

Several people have asked for an update on development of the "Fast modes" in WSJT and WSJT-X.  So here's a brief summary.

First, a review of some relevant terms and motivations.  It's convenient to think of the various WSJT protocols ("modes") in two groups:

*Slow modes* -- JT4, JT9, JT65, and WSPR.  These modes are designed for communication with extremely weak signals -- often too weak to be heard. Target propagation modes include EME and long-distance troposcatter on HF-and-up bands, and QRP Dxing on the LF, MF, and HF  bands.  Relevant signal amplitudes are approximately constant over a minute and more, aside from so-called "libration fading" for EME. Transmit/receive sequences are 1 minute for JT4, JT9, and JT65, and 2 minutes for WSPR.

*Fast modes* -- JTMS, FSK441, ISCAT, and JT6M -- and now also *FSK315* (implemented in WSJT) and *JT9E* through *JT9H* (implemented in WSJT-X. These modes are made for communication with rapidly varying signals:for example, meteor scatter, ionospheric scatter, airplane scatter, and scatter off the International Space Station.  The decoders are designed take advantage of short enhancements of signal strength.  T/R sequences are 30 seconds (or sometimes even shorter).

Bill, ND0B, has implemented a trial version of FSK315 in WSJT.  Think of this mode as FSK441 slowed down to 315 baud; the bandwidth is therefore narrow enough to make the mode legal in the "CW and data" portion of the 10 meter band.  Bill and a few others have been experimenting with FSK315 and also ISCAT-A on 10 meters, under dead-band conditions, using meteors and ionospheric scatter propagation.

I have implemented experimental submodes of the JT9 protocol in the program branch WSJT-X v1.6.1.  As with JT4 and JT65, letters following the "JT9" designator indicate increased spacings between the FSK tones. Traditional JT9 (now also called JT9A) has tone spacing 1.736 Hz, so the signals used at HF and below have total bandwidth 9*1.736 = 15.6 Hz.  The widest of the new submodes, JT9H, has tone spacing 200 Hz and therefore bandwidth 9*200 = 1800 Hz.

When used with the standard 1-minute periods, the wide JT9 submodes should be useful for the same purposes as the wide JT4 submodes: microwave EME, for example, where libration fading can cause Doppler spreading of 100 Hz or more.  Used in this way, all JT9 submodes are "slow" modes; they use 1-minute T/R periods and keying rate 1.736 baud, and they send the full 85-symbol message protocol in 85/1.736 = 48.96s.

Optionally, the wide JT9 submodes can now also use "fast" keying rates equal to their tone spacing.  "Fast JT9H", for example, uses keying rate 200 baud, so the full message protocol is transmitted in 85/200 = 0.425s.  The message is sent repeatedly for the full Tx period, in the same way as done for the other fast modes.

The fast JT9 submodes should be very effective for meteors and ionoscatter propagation, especially on the 6 meter band.  Sensitivity should be similar to ISCAT, or perhaps slightly better.  Because JT9 includes strong forward error correction, decoding results are like those for all the slow modes: you should see messages exactly as they were transmitted, or nothing at all.

Tests of the fast JT9 submodes are currently under way, with excellent results.

   -- 73, Joe, K1JT"

Good Es on 6m and 10m WSPR

Es is good today on both 10m and 6m WSPR with lots of spots both given and received. On 6m CT, EA and CN8 have all been spotted and my own signals have been spotted in Morocco and Portugal on 6m. Apart from CN8, no stations spotted or spotting me on 6m outside Europe.

Sunspots and 10m - Sat Aug 8th 2015

Things are looking slightly more promising on 10m. Sunspot number has risen to 95 (K=3) and 10m propagation is expected to be "fair" rather than "poor" as it has been for weeks. Whether we see any real DX on 10m WSPR remains to be seen.

4X1RF (3519km) again spotting me on 6m WSPR

Since lunchtime, 4X1RF (3519km) has again been spotting my 1W ERP WSPR signal on 6m. I am pretty convinced this is E layer, but remain skeptical this is multi-hop Es which is the conventional wisdom. 3519km is a long way for Es multi-hop. This path seems pretty regular so I wonder if some other E layer mechanism is going on? Possibly some E layer chordal hop?  Signal levels suggest even lower power would have been successful such as 250mW or even less. So far today he has spotted me 6 times already. He has spotted me on several days this season as well as last summer. There are a reasonable number of stations active on the 6m WSPR band.

UPDATE 1607z:  Yesterday was one of the worse days I can recall in recent months on 6m and 10m WSPR. Today has been one of the best with plenty of Es on both bands.  Both are "magic" bands and you can never be quite sure what the day will bring.

UA3ARC spotting me very early on 10m WSPR

Already before breakfast my 500mW 10m WSPR beacon has been spotted several times on Moscow by UA3ARC (2446km) . This could be F2? Most probably Es, I guess.

UPDATE 0834z:  Widespread Es on 10m WSPR early with spots from right across Europe already. On 6m WSPR no Es spotted yet.

Sunspots and 10m - Fri Aug 7th 2015

Sunspot number is 80 today (K=2) and 10m remains "poor".

UK prices for Japanese radios

My comments on UK prices for Japanese radios was also reported on www.amateurradio.com yet not one dealer or Japanese manufacturer has said, "not so".

OK, they may not read the blogs mentioned (mine and http://www.amateurradio.com/) but I think I must have hit the nail on the head and that we are indeed paying too much for Japanese gear here in the UK. My own blog is read by thousands most days, so the silence tells me a lot.

Get those prices down please.

I want dealers and manufacturers to make fair profits and to remain in business but, please, don't rip us off.

Sunspots and 10m - Thurs August 6th 2015

Sunspot number is 87 today (K=2) and 10m is expected to remain "poor". Es today has been pathetic and I have seen no evidence of any F2 propagation on 10m.  Roll on autumn and winter conditions now!

Poor Es

Although here I am talking here of 10m and 6m WSPR, things may be better on other modes with higher levels of activity. So far today I have received just 1 spot on 10m WSPR by Es and none at all so far on 6m.  It feels like the Es season is largely over, although this may just be a blip.

UPDATE 2145z:   There was quite a bit of Es on 10m WSPR this evening, but nothing seen by Es on 6m WSPR. I am going QRT now on all bands until breakfast time tomorrow.

2m/70cm beam down

After about a year of service, I have taken down my beam for 2m and 70cm which was not working as it did. In the near future I want to erect big-wheels instead. According to Wimo literature they have an omni pattern and a single big-wheel has a gain (horizontal) of 3dBD. Spacing between a 70cm big-wheel and a 2m big wheel needs to be 1.5m. This gain is a little down on the beam but needs no rotating. At the moment I think I'll install a single big-wheel for 2m and one for 70cm both fed with low loss coax on a single mast as high as I can. These should suit my operating fine. I monitor beacons and take part in some 2m and 70cm contests from home in a non-intensive way. A couple of big beams would be nice but these would need a rotator.