FT8 with WSJT
FT8 is now hugely popular it's a weak signal mode and stations usually run just 5 watts power making the Xiegu 106 all band transceiver a good choice without spending to much money - You may of course already have a suitable transceiver.The software will run on windows or on a Raspberry pi. You will have to buy the de-19 separately it does not ship with the transceiver.
If the program stops decoding or does not
even start to decode despite you seeing numerous signals in the water fall it
could well be a
clock issue so install something like Atomic
clock or Meinberg
to set the PC clock correctly and it should start decoding ok.
Online
manuel for Xiego G106
transceiver
https://manuals.plus/xiegu/g106-hf-portable-transceiver-manual
WSJT and JTDX download link
https://wsjt.sourceforge.io/wsjtx.html
https://sourceforge.net/projects/jtdx/files/
Grid tracker download ( You need the WSJT program
for it to work )
https://gridtracker.org/index.php/downloads/gridtracker-download
You will need to know your grid locator
https://www.karhukoti.com/Maidenhead-Grid-Square-Locator/
Below is a screen shot from WSJX
taken from my windows laptop - it would look the same from a Raspberry pi
screen - the bottom right hand side is a shot of one of the Grid tracker
screens placed for convenience
Below is a partial screen shot
from the Grid Tracker Programme
FT8 with the uSDX transceiver
range
I bought the 8 band transceiver specifically for FT8 operation. I could not get the CAT control to work. But it's easy enough to use it with either VOX or PTT
You should be able to find both the below transceivers on one of the Amazon sites. This transceiver is of Chinese origin and as such is sold/manufactured under various brand name's
There is now also the 3 band uSDR transceiver which is not bad for the money
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One of the biggest problems that I have found with these transceivers is the lack of information especially regarding the cables. The software varies from device to device you may find that you have more or less functions than someone else with the same transceiver, my 8 band unit does not have the internal electronic keying software.
It's worth mentioning that you will need to adjust some of the menu settings to get the most out of this transceiver, notably the bias settings. I left the min bias settings to 20 as could see no reason to change it but the max bias setting was 160 on my transceiver which gave a R.F output on CW of about 3 watts, I increased it to 175 which gave me an output of about 5.5 watts. It could be increased further to give an output of 8 or 9 watts or more but maybe it could distort the SSB output or put unnecessary strain on the PA stage, but as I mainly use CW and consider 5 watts as being adequate for QRP so I have left it at 175.
I have set the SWR meter in menu settings to FwdRef which I think is the simplest to understand. My readings show F=2.75 W R = 0.00W however that does not equate to actual power output because my dummy load says I am have double that output i.e 5.5 watts. So I would check the real output with a dummy load to prevent overdriving the PA. The SWR measurements would appear to be 100% accurate or close enough.
I bought a second unit which did have the keying software incorporated, and the factory bias setting was 220 which indicated a output of 10 watts and also my dummy load / power meter indicated the output as being 10 watts, I reduced it to 175. which gave me an output of about 5.5 watts. This unit also has the 160 meter band and the 50 Mhz band. So it's worth checking what level of software is on the unit you are thinking of buying.
The furthest distance I have got with this transceiver on 20 metres (CW ) is just over 5,000 km with an indoor dipole with a 559 report. I have had numerous contacts with USA stations the furthest I have got on FT8 was just under 6,500 km (KP4).Which considering the power of the transmitter and the poor antenna is remarabkle. Note that using an external power supply gives the same power output as when on batteries ( not checked this on the 2nd unit I purchased as yet)
It's still early days for these transceiver, you either like them or find them to much trouble, I guess you get what you pay for but I find them fun to use.
When I plugged a strait key into the key socket mine immediately went to transmit. You may rectify the problem by putting 'swap key' to 'on' in the menu but it may then effect your electronic key i.e you will get 'dots' instead of 'dashes'. If that happens just rewire your strait key jack socket using a (trr) jack plug as shown.
FT8 the final solution
I use a raspberry pi to run the WSJX and the JTDX programs, I find JTDX a bit more sensitive or perhaps that's because it's in the software to be able to display stations that are really weak but probably little chance of being able to work them. The programs run really well on a raspberry and the USB soundcard and PTT units cause no problems.
I have re written things to make it a bit clearer and show how easy it is to get the TCVR working on FT8
The same cable is needed for both VOX and PTT operation I suggest you use one of the cheap USB soundcards
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For VOX operation
The first lead is from the soundcard headphone socket into the TCVR mic socket, which I made up by joining a TRRS to a TRS lead as in the above diagram - your cable colours may be different. You could buy a commercially available trrs to trs cable but I have not tried it so don't know how they are wired. This lead is the same for VOX and PTT operation
The second lead is a standard trs to trs jack lead going from TCVR headphone socket to the soundcard mic input socket
Another way to make the first cable up is to join a piece of single core screened cable between a TRS plug one end and a TRRS the other end, as in the below diagram
Settings on the transceiver and within the WSJT program
Transceiver VOX (on) Noise gate (12) Tx drive (3) Mode USB
WSJT program Select correct soundcard / select right or left channel / VOX on
This method does work 100% ok
That's it you should be all set up for VOX operation
For PTT operation
Use exactly the same two cables as for VOX. For PTT you will need to build the PTT circuit, as most modern PC's don't have a serial port you will need to obtain a USB to serial port convertor.
Make a lead up to go from your PTT unit that you have made and plug into the 'key' socket which makes it easier than having another cable going to the mic socket jack plug. Make sure you select USB and you should have no output until you activate 'transmit' within WSJT, if you immediately see an r.f output you have most likely left the tcvr in CW mode or wired the plug up incorrectly
Settings for PTT operation
Transceiver VOX (off) / Tx drive (3) / mode USB
PC and WSJT settings Set com port up / VOX off / select correct sound card / select right / left audio channel as per the lead you made up
If you are using a Raspberry pi, go into ' sudo raspi-config'
in the Interface options, enable serial port
in the settings page of WSJT or JTDX implement as in the below diagram
Note : when selecting the port it will not show a COM Number the serial to USB device will show as something like ' dev/ttyUSB0'
You are all set up for PTT operation
Interference between Raspberry pi and the monitor
I re-sited my raspberry pi 4 / monitor and 8 band uSDR transceiver and found that I had introduced a problem, the monitor was now picking up interference and on transmit there was severe interference, I tried the usually things like putting ferrite cores on the cables, all to no avail. Nothing had changed except that I had used a brand new cable between monitor and raspberry pi because it was shorter and more convenient, replacing the cable with the original one and the problem went away. The new cable had been a really cheap one!
FT8 using the 3 Band uSDR Transceiver
You need to make up a TRRS to a TRS lead to get the audio from the transceiver headphone socket into the MIC socket of the computer. TRRS into headphone socket on the transceiver ( See the above diagram referring to cables )
I can't say I was to happy with the transceiver on FT8, I made a PTT unit up ( using VOX it was picking up noise from somewhere despite the transceiver settings being correct ) using PTT it worked but the transceiver casing got quite hot, so have giving up with it. It however does make a really good C.W transceiver with reports from about 5,000 km away. I have not tried using it on SSB.So if you want a cheapish transceiver for FT8 I recommend the 8 band uSDR transceiver.
Earth loop
There is always the chance of feedback getting into your computer, which could introduce a hum onto your signal or the worst scenario it could damage your soundcard ( another good reason for using a cheap USB soundcard, better that unit gets damaged rather than the soundcard in your laptop ) With the power from these uSDR transmitters being so low it's highly unlikely anything amiss will occur and it's probably not worth the effort of buying or making an interface up. With higher power transmitters I always use some transformers to prevent earth loops etc. Should you deem it necessary you could implement the below circuit.
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Antenna's for the SDR transceivers
| The antenna on the right came with my 8 band
usdr transceiver, they can be bought separately on Amazon, etc. At first I thought there was something wrong with the unit but with a SWR meter between the transceiver and this unit on 14 MHZ using the supplied whip it tuned ok and gave a more than acceptable SWR reading. I have tried a 66 foot and a 132 foot length of wire and the same result, an acceptable SWR reading. |
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The Z match is a nice little ATU, but the so called s.w.r monitor with l.e.d and switch is a waste of time, I doubt you could tune anything to an acceptable s.w.r using it, more to the point you may think the aerial is tuned, when its not and end up damaging your p.a. Anyway to my mind you should always be using a s.w.r meter, so ignore what the l.e.d. is indicating and use a cheapish CB type s.w.r meter in conjunction with the Z match.
