[Lowfer] New JT9 Experiment

N1BUG paul at n1bug.com
Mon Dec 10 09:02:49 EST 2018


The aim of the SlowJT9 project is to bring back the 2, 5, and 10
minute JT9 modes with the hope of facilitating more weak signal QSOs
on MF and LF.

We need to see if the slower modes are providing copy where the
regular 1 minute JT9 mode does not.

I am now transmitting alternating JT9-1 and JT9-2 on LF at a
frequency of 137.350 (1350 Hz audio with a USB dial frequency of
136.000).

If some receiving stations will monitor both modes and send
reception reports, we may begin to collect useful data.

It is easy to receive both modes at the same time. Use any recent
version of WSJT-X to receive JT9-1. Use SlowJT9 version 0.9.11 or
later to receive JT9-2.

Each morning, participating stations please send your complete list
of decodes for both modes to me.

The future of this experiment will depend on participation. I hope
it will generate enough interest to collect meaningful data on the
relative performance of JT9-1 and JT9-2 on LF. Later, when JT9-5 and
JT9-10 are working I propose to extend this experiment to test those
modes.

I invite other transmitting stations to join me in these experiments.



*** Note ***

One limitation of this experiment is that it will only be possible
to compare as follows:
JT9-1 to JT9-2
JT9-1 to JT9-5
JT9-1 to JT9-10

I believe there is no easy way to receive any combination of JT9-2,
JT9-5, and JT9-10 simultaneously (without going back to a format
which I cannot beacon on multiple modes). Therefore it will not be
possible to make direction comparisons between the slower modes as
far as I know.

I had thought about using WSPR as a standard reference for
comparison to all JT9 submodes but this does not appear to be
practical with present limitations on audio frequency for the 5 and
10 minute JT9 modes. It would require a wide spread in transmitting
frequencies or multiple receivers at the monitoring stations. My
antenna tuning is too sharp to allow transmitting on widely
separated frequencies.

Comments and suggestions on improving this test are welcome!

Thank you and 73,
Paul N1BUG


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