Testing the new JT10 Digital mode

Today I did some first quick test with a new digital mode. This mode, JT10 is derived from JT9.
Below you will find the explanation by Igor UA3DJY

First I have installed the latest version of the JTDX software and list on 20 meter 14080.00 khz.

I checked all the settings in the new (beta) software. some of them didn't work now, but this wasn't problem to start the first transmission on 20 mtr,

After some CQ on 20 I decided to switch to 40 mtr and made some contacts.

Message from Igor JTDX developer.

New mode "JT10" in JTDX 17.8 (coming soon)
Hi All,
JT10 mode is derived from the JT9 mode and has 10 tones where two of them dedicated to synchronization pattern, rest 8 are the message data.
Each tone being transmitted for 6912/12000= 0.576 second, minimal distance between the two neighbouring tones is 4*12000/6912= 6.94(4) Hz.
Frequency bin width is 12000/6912= 1.736(1) Hz, so there is always a gap between the two neighbouring tones.
Whole spectrum occupies 6.94(4)*9 +1.74= around 65 Hz. Fano decoder is used for JT10 mode.
16 tones (8+8) are used for SYNC pattern, 69 tones allocated to the message data, total 85 tones being transmitted per 85*0.576= 48.96 seconds time interval.
There are several ideas behind this approach:
- usage of two tones for SYNC pattern can simplify to distinguish harmonic based signals (JT10b and JT10c), also these QRM-ing signals can be decoded and subtracted from the whole signal in the future SW versions
- wider tone spacing shall bring better resistance to the Doppler frequency spreading in comparison to JT65a mode
- wider tone spacing shall bring better spectra overlapping capacity in comparison to JT65a mode, and more signal density on the band if signal subtraction is used in the software
- relatively narrow bandwidth of JT10 signal will allow to get better band capacity in comparison to the JT65a mode.
So far it is not clear if JT10 will go to the public use, one of the reasons that can stop it's usage is the relatively small SYNC pattern, and there is a long way ahead to make it more attractive one in comparison to the
JT65a mode.
73 Igor UA3DJY


73 Gerard

GEOMAGNETIC STORM WATCH: A large canyon-shaped hole in the sun's atmosphere is facing Earth and spewing a stream of solar wind toward our planet. Estimated time of arrival: 2 to 3 days from now. This has prompted NOAA forecasters to issue a geomagnetic storm watch for March 28th when storm levels could reach category G2--that is, moderately strong. Auroras could descend from the Arctic Circle to northern-tier US states from New York to Wisconsin to Washington. Visit Spaceweather.com to learn more about the incoming solar wind stream and what makes it so potent

Above: This canyon-shaped coronal hole (CH) is a magnetic fissure in the sun's atmosphere where solar wind can escape and flow towards Earth. The underlying image, taken on March 25th, comes from extreme UV telescopes on board NASA's Solar Dynamics Observatory.

Yesterday I had a nice contact on 40 mtr with OD5ZZ Libanon

Nice opening this evening on 20 meter to Brazil

The bands where in a good shape this evening. On 40 meter I made contacts in phone with Algeria en Turkey. On 20 meter to Brazil with psk31

<QSO snap>
>>>Hello Gerard Nice to meet you
Report:  599 599

NAME: Elizeu Eliz r QTH: Caucaia , Ceara
GRID LsN: HIDqf
BTU PA7GMU PA7GMU  DE PT7AV KN a!
PT7AV de PA7GMU
</QSO snap>

73 Gerard

Today I had a very short contact with Ted K2GAV. Conditions where to bad to have I long talk, so I appreciated that I got this nice QSL card

My first self build 20 meter HF antenna.

Because I was always planning to build an HF antenna I recently purchased an analyser.

With this device you will be standing to tune antennas on the right frequency.
It is also possible to make impedance measurements in order to get the correct matching between antenna and transceiver.

I have examined which antenna the best for me is to build  that I can use during the PACC contest.
The antenna must meet a low radiation angle. This is needed for good DX purposes.

The above example are from a 21 Mhz VDA

Most HF antennas are large and therefore a problem to post them in the backyard.
After some searching on the Net, I discovered one of  PA3FYM (Remco den Besten) videos on YouTube. In one of his videos I saw a VDA (vertical dipole array) and is easy to build.
Also, the dimensions are limited in order to build a 20 meter antenna.

Fortunately I had most of the stuff already in the house and I immediately started building the antenna. The entire construction diagram of this antenna is described in the DKARS magazine of March 2015. After some saws, drills and screws I put the antenna in the backyard and performed the first measurements. An exciting moment, because you know, finally, never whether it is in practice, as described in theory.

The antenna is as expected a little too low in frequency. A little cut on the bottom two wire solves the problem.

first setup in the garden.

So, I am almost ready to participate the PACC contest.

Good DX. 73, Gerard

IMG_1382.MOV

Special event station PD16XMAS on 40 meter