[Elecraft] K3_JT65_Digi mode

[Lance Collister]

Ken Roberson wrote:
> Hello All,
> 
> The K3 has been working flawless on digi modes.
> About 2 years ago we started using JT65 on HF,
> It the same that we use for EME weak signal moon-bounce .
> With low power and a dipole we are able to work
> EU almost every day.
> Before I built the K3 I was using a homebrew 4 watt rig .
> JT65a is part of the WSJT software package, It's free software.
> The call freq on 20 Meters is 14076, we operate + or - abt 600 hz from 14076.
> Check it out , In the day time u can hear the tones of JT65A on 14076.
> In the morning EU is coming in and in the afternoon - evening JA and VK Land .
> http://physics.princeton.edu/pulsar/K1JT/index.htm
> 73 all good dx Ken K5DNL
> 
> 
> 
>       
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> 
Good point, Ken!

Since most of the folks here are K3 users (with built-in digital mode capability 
on 6m) I will add this to Ken's comments... I have worked stations as small as 
100w using 5 element yagis on 6m EME using the very sensitive JT65A mode.  There 
was no signal audible from such small stations, but the message sequences were 
successfully decoded and the signal trace is very easily observed on the SpecJT 
waterfall screen while JT65A mode is running.

And I'll bet you had heard the 6m band was dead!  The secret to working 6m EME 
with JT65A is:

1) Set up a schedule with a large 6m station and run the schedule for the hour 
that the moon is closest to the horizon at your QTH, so it will pass through the 
ground gain antenna lobes that provide the extra gain when your antenna is aimed 
at the horizon.

2) Choose a good time of month when conditions for 6m EME are optimum (there are 
good and bad days every month, depending on where the moon is in its orbit around 
the earth).

3) Transmit and monitor EVERY minute of the schedule.  Signal peaks on 6m EME can 
be very short, and everything must be exactly right for you to decode the very 
weak EME signals.  For example, two of the factors are that the polarity of the 
signals continually rotates, and the setting (or rising) moon must happen to be 
passing through one of your antenna's narrow but high gain ground gain lobes.

4) On top of everything else, it is very rare for both stations to copy each other 
at the same time (due to the polarity changes), so the standard EME exchanges and 
protocol need to be followed.  These messages are automatically generated by the 
user in JT65A mode, and the procedure is explained there (press F5 when running 
JT65A mode).

If anyone is interested in learning more about JT65A mode or 6m EME, more 
information is available on my website:

http://www.bigskyspaces.com/w7gj/Welcome_to_6m_EME.htm
http://www.bigskyspaces.com/w7gj/JT65.txt

Gud luck and DX to all!  VY 73, Lance

-- 
Lance Collister, W7GJ (ex: WN3GPL, WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8)
P.O. Box 73
Frenchtown, MT  59834  USA
QTH: DN27UB
TEL: (406) 626-5728   URL: http://www.bigskyspaces.com/w7gj
2m DXCC #11, 6m DXCC #815