630m

After a brief period on JT9 RX (nothing copied), I have gone on WSPR (10mW ERP,20%).

ARRL book about JT65 and JT9

There is an ARRL book on the digital modes JT65 and JT9. These are among my favourite modes and ideally suited to QRP. I have used JT9 on bands up to 10m. I have used JT65 on bands up to 6m.

See http://www.arrl.org/shop/Work-the-World-with-JT65-and-JT9/ .

At the moment there is a special ARRL deal so you get this book free when you buy a new ARRL Handbook.

JT65 and JT9-1

Tomorrow, I may give these modes a better go. In recent days I have reverted to WSPR (which I can monitor in the lounge) but feel the urge for more 2-way QSOs, which is very hard on SSB and CW currently as a result of my stroke.  Hopefully my normal voice will gradually return.  At the moment speaking is very tiring as I get breathless. and forming words is hard going.   CW is also not so easy.  JT65 and JT9-1 are perhaps the best 2-way modes for me right now. They require limited keyboard skills which I can manage.

JT9 QSO

As my vocal chords are still not right, I am trying to limit myself to digital (keyboard) modes like WSPR, JT65 and JT9. This afternoon I worked SV1BHF on JT9 on 20m when using 5W.  No great DX but I see from PSK reporter I was copied in the USA as well.  CQs by me on 10m and 6m in JT65 went unanswered. I have now gone back to 6m WSPR.

We had our 3rd Virgin Media broadband outage this afternoon.  I reported it (someone already had) and it was quickly fixed (under 3 hrs) but it is annoying when it happens. Still, the  broadband is fast now with claimed speeds up to 50MB. Even over wi-fi it was almost 30MB, so can't complain.

A couple of 20m JT9 QSOs in the log already

QSO with UA4PPQ on 20m JT9-1 today

Well that was pretty easy: I loaded the latest software, listened a bit, then called CQ in JT9-1 and managed a couple of QSOs within 15 minutes (it takes about 6 minutes per QSO). Reports also received from the USA, Canada and Siberia, so everything working well.

The mode certainly seems to be very useful on HF and takes up very little bandwidth - the scale on the screenshot above is in Hz above 14.078MHz, which is the USB dial frequency.

Using 2.5W to the end fed Par 10/20/40 antenna, but reports suggest much lower power would be fine too. Now QSYed to 28.078 MHz USB dial JT9-1 and calling CQ.

JT9 mode on HF

Julian G4ILO has been having some good success on HF with JT9 mode, so I am encouraged to have a go too. This afternoon I'll be firing up on HF, probably 20m.

Results with this mode on MF were very encouraging giving me my first international 2-way QSO (as opposed to WSPR report) some months back. The slower JT9 modes are similar to WSPR in terms of weak signal performance, but allow basic real 2-way QSOs similar to JT65 mode QSOs.

PSK reporter now shows JT9 spots, so it is possible to see where your signal is reaching even if a QSO does not result from a CQ call.  The new JT9 Yahoo group is rapidly gaining members and is worth joining if interested in this new mode.

Recommended JT9 mode frequencies are:

10m  28.078MHz
15m 21.078
17m  18.104
20m 14.078
30m 10.130
40m 7.078
60m 5.2872
80m 3.578
160m 1.838

JT9 software can be downloaded from http://physics.princeton.edu/pulsar/K1JT/ As updates are still occurring it is best to check the site for later versions regularly.  The user guide for all WSJT modes is worth reading.

500kHz JT9-1 test this evening

G3ZJO and I have reported each other's 500kHz WSPR signals and each managed to get reports from close on 1800km away but, despite being only 50km or so apart we have yet to work each other on MF. This evening we are going to attempt a WSJT mode QSO using JT9-1 mode with 1 minute TX periods. I'll report back later how we get on!

500kHz WSPR tonight

My last post with this title got corrupted when I tried to edit it, so this is a shortened revised version. 500kHz WSPR this evening has been very good. In the last couple of hours I've been getting 8-9 reports with each transmission slot when running less than 50mW ERP. Best DX 707km to DG3LV.

500kHz WSPR reports this evening

I've downloaded the latest version of JT9 software and hope to try this for 2-way QSOs later this week on 500kHz. My current problem is the S8 noise floor which I hope to reduce by using a better sited E-field probe or loop antenna (for RX only) further away from the house.

There are still plenty of CW stations on 500kHz. One evening last week I had a very enjoyable CW QSO on the band with G3XIZ. Semi-locally there are around 3-4 stations on a regular Sunday morning 500kHz CW net.

First signals seen on JT9-2 mode

On 500kHz this morning PA0A and G3ZJO were testing with the new JT9-2 weak signal mode. Not yet copied Eddie, but PA0A was coming through well. This is a screenshot with his decoded signal overlaid.

500kHz first JT9-2 signal received

JT9: a new digital mode for MF and LF

Hot news from Joe Taylor K1JT on the RSGB LF Yahoo group this evening about a new 9-FSK digital communications mode (for 2-way QSOs rather than beaconing) optimised for MF and LF bands. With winter approaching and better LF conditions, this is an exciting development.

The wide graph display for JT9

"I invite you to try a new digital mode called JT9, designed especially for making amateur QSOs at MF and LF. JT9 uses the structured messages introduced in 2003 for the JT65 mode, now widely used for EME and for QRP operations at HF. JT9 can operate at signal levels as low as -27 dB (in a 2500 Hz reference bandwidth), with one-minute timed transmissions. It also offers slower transmissions of 2, 5, 10 and 30 minutes duration, and the slowest mode can decode signals as weak as -40 dB. With one-minute transmissions, submode JT9-1 has a total bandwidth of just 15.6 Hz -- less than one-tenth the bandwidth of a JT65A signal. The other submodes are narrower still: a JT9-30 signal occupies about 0.4 Hz total bandwidth.

Note that these JT9 sensitivity levels are comparable to or better than those of WSPR, which uses simpler messages and is not intended for making 2-way QSOs.  JT9 has much higher throughput and reliability than QRSS CW, including DFCW modes.

JT9 is implemented in an experimental version of WSJT called WSJT-X. Some further details can be found at http://www.physics.princeton.edu/pulsar/K1JT/WSJT-X_Quick_Start_Guide.pdf , and an early version of WSJT-X can be downloaded from
http://physics.princeton.edu/pulsar/K1JT/WSJTX_01r2695.exe.

Please note: WSJT-X is in an early development stage. A number of improvements and enhancements are already in the works, and others will surely be added. 

Your feedback will be much appreciated!

-- 73, Joe, K1JT"