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Some Tips On Using WSJT/JT44
Most 144mhz skeds are being run on 144.150-144.170mhz
1. Be sure you PC clock is set to WWV within 1 second or
Note - It is possible to get only 1 way copy if one the stations PC clock is too far off from WWV.
Note - your PC Clock should be set to local time. Set your WSJT software SETUP/OPTIONS
UTC offset amount there to get correct moon data for JT44 mode.
2. Be sure your receive noise level is set to 0db.
3. Look for software Sync by observing
the DT field. For an EME signal
you should see
a DT = +2.5 or close to it. For tropo Sync your DT field should show DT = +0 < /FONT > . These are
approx. values and they can vary some.
4. Keep an eye on the RED line.
That is where you should see a peak to show a received
If you see a peak in red line take a look at the DT field to see if you got program sync on that signal.
5. Since WSJT/JT44 can scan + -
600hz on 144mhz
you do not need to worry about the doppler
as much. 144mhz doppler should be less than 600hz in most instances . On higher frequences this is not
the case. The higher in freq. you go (such as 432mhz) the more important it is to use your RIT to compensate
for doppler. 432mhz doppler can easily exceed 1mhz.
6. Use the INCLUDE/EXCLUDE during a
to include the last decode or exclude the last
decode from the bottom message average box. This is handy to keep a garbage decode from messing up the
information in the message average decoded box.
7. Most signals will start to decode at
a level of about -25db approx. You should get
good decode at levels around
-18db or better . This is about -10db below what you could detect if using cw mode.
8. Only pay much attention to the
DF (difference in freq) if you see a good DT and see
a good peak on Red Line
You can get all sorts false DF readings when you do not actually have software sync.
9. If you do not have elevation control
most yagi's will only work from about +2deg to
of moon. Expect to
have best results when your moon is in the 5-10 deg range .
10. Due to Spatial and Faraday
rotation there is a real advantage to using X-Pol
so that you can xmit
on one polarity and receive on another. Faraday rotation can take a HZ signal and rotate it at times to a VERT signal.
That can give you up to 20db of loss on the receive signal if you are not able to compensate by changing your receive
polarity. Faraday rotation is caused by the ionospere and the amount of faraday changes all the time. There are good
days and there are bad days when it comes to faraday rotation.
11. Most EME skeds are run using standared EME format. There is an advantage though to
using standard JT44
Non-EME format since it requires one less sequence (starts off with BC+Report instead of just BC in EME format).
If you have a very limited EME moon window (due to not haveing elevation control) you might consider this.
BC+Report+R is a valid contact no matter which format is used. If you wish to try it this way it for sure would be
a good idea to clear it with your sked partner 1st.