MFJ RigPi Station Server

This is a fairly new product from MJF, it is the MFJ-1234 also known as a RigPi Station Server (RSS) which uses a Raspberry Pi 3 for controlling radios, it has a CW keyer and it can control antenna rotors. The RigPi includes add-on boards for audio and Morse code keying. The project website is: https://rigpi.net/

Running WSJT-X on the RigPi

Three weeks later after I announced the RSS I received my RigPi and I was able to work on it. My primary interest would be to use it for WSJT-x and derivatives such as JS8call on field days. So the requirements are that the RigPi should take control of my Yaesu FT-857 running on batteries. Also the RigPi should run on batteries etc. Audio from the FT-857 goes to the sound card controllable via alsamixer on the Raspberry Pi, also audio from the RigPi has to go to the FT-857, and we need full CAT control over the transmitter. For this rest in this article I want to explain what you need to get everything up and running besides the RigPi and a 5V USB to USB-C power supply.

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Figure 1: This is what’s inside the RigPi, on the botton a Raspberry Pi, in the middle a CW keyer and on top a sound card interface.
foto2
Figure 2: This is how you patch the RF-45 to 6-pin DIN cable, the set-up is the same as with other MFJ projects like the MFJ 1204, so you use schematic C to get it working the Yaesu 6-pin DIN interface.
  • You need a RJ-45 to a 6-pin DIN cable for the FT-857, this is the same cable that you
    need for the MFJ-1204. It comes with a patch (schematic C) as shown in figure 2.
  • You need a UTP patch cable to a nearby router, all could also be done via wifi if it is fast enough, I preferred the UTP patch cable set-up.
  • A HDMI cable for connecting the RigPi to a monitor, this is what you need to configure the Raspberry Pi.
  • A USB mouse and a USB keyboard for the Raspberry Pi, also required for setting it up.
  • A CAT-6 to USB cable for a FT-857, this is the CT62-U from Yaesu to the 6-pin CAT interface on the FT-857.

With this all you get a wired-box on top of the transceiver, this is what the MFJ-1234 does, it is a hub and a processor at the same time:

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Figure 3: so this is what you get when you connect the MFJ-1234 to the FT-857
  • WSJT-x was already installed on the RigPi, so we start it up and configure it in the
    best possible way.
  • Due to the audio routing in this experiment and the capabilities of the FT-857 select
    data/pkt mode in the radio tab under settings in WSJT-x, USB does not work there unless you modify somewhere the FT-857 on the front MIC connector. I didn’t do this (yet) because you can live without it with WSJT-x.

At the end of the day I was able to send and receive some FT8 data, and also to make some QSOs. The ALC indicator on the FT-857 should be visible, and also you need an external PWR/SWR meter to see whether something is transmitted and that nothing is reflected towards the radio. This is no problem on a field day.

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Figure 4: And this is evidence that I was able to make a few QSOs in FT8 on 20m

If WSJT-x works the way you like it then configure VNC on your laptap, tablet or whatever you had in mind, and demonstrate that you can control the RigPi. From this point on you only control your RigPi via the laptop, this is the point where you can remove the HDMI table, the USB mouse and the USB keyboard. Screen resolution and so on should be adjusted under Raspberry Pi settings so that it is acceptable for the external laptop display. So this is what I got in the end, as is shown in figure 4.

Todo’s

There are few todo’s with this project:

  1. Is there need for an audio in on the microphone of the FT857, seems only possible with an extra cable, currently I do this in the data (or digi) mode of the FT857,
  2. How do I update the WSJT-x software on the RigPi without affecting the rest of the software, it came with WSJT-x 2.0.1 GA
  3. Is the RigPi fast enough to run JT-4? Also, is it fast enough when there is a lot of band activity. Still have to find out.
  4. Find out whether a crossover cable works to any laptop, in other words, can I avoid to carry a router intp the field.

Last update: 22-Jul-2019 11:15 PA1EJO

JTAlert

I think this is one of the tools you want to have next to what you already have for the digital modes in hamradio. JTalert is available from https://hamapps.com/ It is helpful because it gives access to https://hamspots.net which is generally faster than https://pskreporter.info/ Also JTalert has automated the way you can log QSOs or query callsigns in various ways. The program can either update your own logbook or a webserver logbook, and it has a lot of filtering for wanted calls, grids, countries, continents, it allows to chat with online JTalert users (just right click on their name and it opens a message window), etc. Contrary to popular believe, JTalert is not a program to replace WSJT-X, instead it works as an overlay for logging and reporting and as far as I can judge, but it does not fundamentally change the way WSJT-X works. JTalert does not make you the superhuman that does not need sleep, or maybe a robot, referring to the talk of Joe Taylor #k1jt in Friedrichshafen.

Last update: 30-Jun-2019 8:06.

Lucky shot

On the 20m band with 85mW WSPR (I measured the HF power) somebody in Japan picked up my signal out of the noise, it is a lucky shot.

lucky shot

Last update: 20-jun-2019 at 9:15

Measure SWR and filters up to 4.4 GHz

Here is a low budget solution for a spectrum analyzer up to 4.4 GHz which the ability to measure SWR up to 3 GHz:  I received from banggood the LTDZ 2019-03-08, for this you need the NWT software made by Andreas Lindenau DL4AL, the reflection bridge below comes from the transverter store, for details see read the fine-print on the PCB.

network_analyzer

I was able to measure the SWR of a 23 cm antenna, and the effect of a short open-ended piece of coax connected to a power splitter (which is a band-stop filter), still studying on the manual and the NWT software. I’m not yet exactly sure how to calibrate the analyzer and the reflection bridge but I found documentation on the website of Andreas.

Last update: 8-jun-2019 11:50

 

logging WSJT-x calls

After a discussion on this in the FT4/FT8 group in facebook the conclusion was

If you and partner do not get all elements (calls, report, R-report and RR), then the QSO is not complete. Many log QSOs after sending RR, but if the other party does not receive it, the contact is not valid. Incomplete contacts will cause errors, for instance in eQSL or other electronic logbooks.

If you find errors in eQSL then browse through the ALL.txt file in the WSJT-x directory, it may confirm that there was actually a QSO.

FT4 and FT8 are in my opinion not every well suited to go through pileups, they are already difficult in analog mode, but it is increasingly difficult to get something established in any digital mode. CW may actually work better.

Please reject FT8 QSOs in eQSL in case you suspect that the essential elements are missing.

Last update: 2-jun-2019 10:05 AM

A garden loop antenna

For the 10 and 20 meter amateur bands there are in my opinion better antenna’s than the often used end-fed which is prone to picking up local man made noise (QRM) because the shield of the coax should be grounded, actually, a ground plane would be useful. Another reason why the end-fed picks up more noise is that they are E-field receivers while a lot of man-made noise (QRM) which is all around our living area has a high E-field component. If you make a loop then you listen to the H-field, the magnetic component, in theory that should give you and advantage.

My active antenna described earlier on my blog is a low-impedance H-field receiver which you can not use for transmitting, it always outperforms the G5RVj which I already have in the garden, on the image below you see a part of the G5RVj (the upper wire is part of it) which is two times +/- 7.8 meter of wire with a central open line feeder, at the bottom of the open line feeder there is a 1:1 balun to convert it to an asymmetric transmission line, 7mm aircell coax.

The image below is what I denounce to be the garden loop. You don’t need a whole lot of garden, actually one high mast in the back of the garden and a lower pole on one side. Construct a triangle with sides approximately 20/3 meter of length (use your analyser to put it just below or above the 20 meter band, or right in the middle if you have the patience for it), and use a 1:4 balun in one of the corners. The Delta loop is roughly 200 Ohm, and we down-transform it to 50 Ohm. The 20m delta loop is resonant at one lambda, so the 20 meter band, and also works at 10 meter. Drawback is that it takes up more space, I have it running as a weekend and sporadic E-season experiment.

IMG_3815 (1)

Be creative and have fun, antennas offer a lot of playground for that.

Status: last update on 2-Jun-2019 7:00