All PSK modes most recent 24 hours

This is on 40m:

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Last update: 14-nov-2018 12:54

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FT8 on 9-nov-2018

The habit is to run it for one or two hours around the morning greyline on 40m, transmit power around 50W, but the bandwidth is only 50 Hz in 8PSK mode.

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The pskreporter.info website produces these statistics.

Last update: 9-nov-2018 10:48

Running FT8 on shortwave

During the last month I was active on FT8 on 20, 40 and 80m, you need the WSJT-X software and there should a way to control the CAT interface plus that you need audio input/output to your PC, so for this I use the microham keyer II. With FT8 the audio level should be such that you just keep the ALC a zero (this can be arranged both in WSJT-X and on the MK2), also the power level of the PA in your transceiver should be at roughly 1/3 to 1/2 of what the transceiver can handle. All advanced options in the FT-991 should be off, don’t use DNF or DNR, no equalizer and no speech processor. Also the bandwidth should be wide open, 3200 Hz is the maximum. This is what I got over the last 24 hours, pskreporter.info is able to produce these graphs.

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My conclusion is that there is nothing to complain about FT-8, this mode is highly resilient and can deal with local QRM, your transmit power can be low, you don’t make spoken noise in the house which is a source of complaints, the FT8 digital mode is very efficient because of its small bandwidth and due to the FSK modulation characteristics. I’m pleased with the interaction time, QSOs are quickly realized, for me it is like hamradio. I’m also pleased to see that FT8 on 40m is in the frequency range where novice amateurs can use it. The only drawback may be, you need a computer so that it would be an extra device to carry in the field if you like backpacking.

The pskreporter.info website produced the graph, it also draws your antenna radiation pattern. The most interesting periods to work in FT8 are around the greyline. The ADI file that is generated by FT8 is manually imported in ham radio deluxe after a day or so, and I will confirm all QSOs on eqsl and lotw. Soon there will be updates to WSJT-X with even a more interactive mode called JS8CALL. (Please read the comment of PE4BAS) As soon as the beta testing is done (I’m not participating) I will take a look at it.

Last update: 5-nov-2018

Panadapter for your rig

Linking everything together

In this setup, the SDR receiver and the PC are a panadapter for the transceiver, a FT-991, but in principle it should work for any transceiver:

  • Install SDRConsole and omnirig on your PC, get microkeyer (or similar) and run it, define three com port COM1 for the radio, COM2 for PTT and COM3 for the mirrored CAT interface. Here we need COM1 and COM3
  • Tell SDRconsole that there is an external radio, via view -> select -> external radio.
  • When you turn the external radio on, it wants to run omnirig, specify here the COM3 port and speed of the mirror CAT line.
  • In my case I also want to use ham radio deluxe, for HRD you go via tools -> 3rd party serial port the connection, here you select mirror CAT port COM3.
  • No virtual audio cables are required, the only thing the SDR does is to listen to its own antenna, the transceiver works with the longwire antenna, SDR console has an option to automute when you transmit, home -> automute is where you need to be.

In the end you should be able to do this:

  1. The SDR and the transceiver exchange all CAT information via COM3, HRD uses COM1 and MK2 takes care of the mirroring between CAT ports. Use the MK2 debugger to check it.
  2. Rotate the frequency dial on your transceiver and the slider on the SDRconsole moves around, also mode changes are transferred.
  3. And the other way around it also works, all actions in the SDRconsole control the transceiver.
  4. You can still use HRD, the logbook receives the correct frequency and the modes via the main CAT or COM1.

See: https://forums.hamradiodeluxe.com/node/42831

Last update: 22-Sep-2018 1:07 AM local

Field activity in PAFF-0113

This was in PAFF-0113 “De kop van Schouwen” on 16-Sep-2018, I had not enough time to complete the required 44 QSOs, so this is what I will do another time.

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FT-857D with antenna
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Surroundings
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Local cattle
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Local cattle
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Evidence of presence
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And another one

Wasn’t all to happy with the local cattle, they are nice but can damage equipment and antenna’s, so I will look for another spot in this area the next time.

Battery for mobile activities

My mobile activities consist of carrying around a FT-857D in the field, it is a radio that can produce 100W, the voltage range is 13.8 +/- 15% or 11.73 to 15.87 Volt. In the ideal case you would have a power source that provides the 13.8 Volt up to something like 20 Amperes which you get during transmit. The current during receive for the FT-857D is around 0.5 ampere.

Solutions so far

I have tried a number of battery solutions, an easy one is, a standard car battery which is rather heavy to carry around. Smaller sized 20Ah AGM batteries exist, but they are still around 5 kg which is also too heavy.

The lead acid battery voltage range is too reduced to produce 100W in the field.  The measured HF output is around 80 Watt for a full battery but less than 50W when the battery voltage drops to less than 12,5 volt, at even lower voltages you will experience that the modulation quality reduces, at least, this is the feedback I got from reception reports at low voltage.

A DC-DC converter is a solution but it is a device that generates RF noise which you don’t want. There is already a lot of power converter noise in our living environment, and the reason to go outdoors is to avoid that noise. Even cars will produce RF noise, there is always something running and you can hear this on the HF bands. If you want a clean environment then avoid the switching power supplies near a receive antenna.

Design requirements

For each active hour in the field you need on average 1,5Ah and the longest continuous session in a mobile setup is approximately 3 hours or 4,5 Ah. The design requirements for backpacking are:

  1. reduce the battery weight less than 1 kg,
  2. battery capacity should be around 6Ah
  3. supply voltage range should be 11.73 to 15.87 Volt
  4. supply amperage should up to 20 Ampere peak and 0.5 Amperes in rest
  5. desire for a voltage and capacitance monitor

Lithium polymere (Lipo) batteries

A four cell (4S) lipo with a capacity of 5800 mAh satisfies requirements 1, 2 and 4 easily, it weighs 580 gram, its nominal voltage is 14,8 volt and with the 20C model you can in principle draw 20 times 5.8 Ampere, which we never do of course. There is only one drawback, the voltage range is too large, it is between 14,6 and 16,6 Volt, so when it is charged we exceed the specification of the FT-857D. The indicator on the Lipo shows the voltage, the capacity remaining is related to that voltage and a lot of other factors, such as temperature and age of the battery. There are various internet sources for this,  see for instance:

http://www.rcuniverse.com/magazine/reviews/1183/ampd14.pdf

The three cell (3S) Lipo battery could be an alternative, but in my opinion it underpowers the radio resulting in cracky modulation reports. So back to the 4S lipo with an add-on where we peak shave the 4S lipo when it is above 15.8 volt. The standard solution is to insert two high amperage diodes in series which takes away 1.5 volt, this is sufficient to reduce to 16.6 volt down to 15 volt which is within the acceptable voltage range of the radio. High amperage power diodes can be found in rectifiers, I found one that handles 35A as a maximum average which can handle peak currents up to 100A or more and voltages up to 500 Volt or more, more than  enough for our intended use, and easy to get.

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The intended use for the standard bridge-rectifier
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In the voltage reducer circuit it takes the following shape
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Use a die cast box able to dissipate approximately 30W of heat
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Use the shrink tube as a tule to protect the cable (I used the thickest audio cable I could find)

The intended use for the reducer is when the 4S lipo goes beyond 15.75 volt, so before the reducer you insert a monitor (that I got via the internet). All used connectors are EC5 which is compatible with the hacker series batteries that come from CONRAD.

Last update: 31-aug-2018