Pirate radio stations around 6MHz have been using that part of the spectrum for many years. They often populate that part of the band, and in the main don’t seem to cause the primary users any issues. The primary users sometimes put a STANAG signal on top of the pirate music station, I doubt they even notice the radio station.
The KIWI now has a Time Difference of Arrival function, you can use this to help identify the likely location of an HF transmission.
This evening 6316.5 KHz was active with a music station, and I guessed this may be located in the UK. I selected 3 KIWI receivers located around the SE of England and achieved this fix.
The accuracy can be very good, but much depends on the location of the receivers relative to the transmitter. I repeated this one a few times, and the location did change but always remained in and around Coventry, Solihull area of the West Midlands.
A further example can be seen in this map, resulted from TDoA Radio Caroline.
Want to try it yourself?
A good place to start is to read this article and my KIWI SDR
(apologies for the SMPS QRM on my SDR its outside of my control and under investigation)
Suffolk Red hosted a field weekend from their field day site at the Suffolk Aviation Heritage site near Ipswich. The weather was set fine, with temperatures close to 30C and with the option to camp out for the weekend.
George M1GEO, Chris G8OCV and I set up the operating tent and populated it with the following equipment.
HF – Icom 7610 and 1.3K Linear from expert
VHF – Icom 7100 and 300w VHF amplifier from Linear amp UK
RACAL push up mast
Power – Honda 2KW generator
The object was to try something new, so I opted for 9e LFA on the Racal push up mast and tried to work as many EU stations as I could on both phone and FT8. VHF seemed quite lively, and with good take off into Europe I was soon working into France, Germany, Denmark and Belgium.
LMR 400 coax was used to keep the losses down, and the masthead amp compensated for any RX losses.
Masthead amplifier for 144 MHz was originally published in the RSGB magazine RADCOM plus issue 1 designed by Ian White GM3SEK. The details are published on his website, detailed as the DG8 low cost, high-performance preamp for 144 MHz.
Over the course of the weekend I completed 50 QSO in 25 squares, the map is shown below. If you are new, or even not so new to FT8 you may find this operating guide helpful.
Some 144 MHz FT8 highlights include.
DL3GAK at 662KM
F4CYH at 673 KM
OZ1BEF at 693 KM
OZ1BP at 698 KM
A while ago I completed the QRP labs WSPR transmitter, you can read about that project in this article. I wondered how easy it would be to set this up in the garden, solar and battery powered.
The QRP labs unit transmits around 200mW, and the idea was to have this running 24×7 transmitting around 80% of the time and band hopping. I have the multi-band option, with BP filters for 3.5, 5, 7, 14 and 21 MHz.
Searching eBay I found a low costs solar charge controller and solar panel. I also needed a voltage regulator to drop the 12v to 5v for the QRP labs unit.
The items I selected are not “high quality” it was more proof of concept. The charge controller is in fact so high quality even China didn’t put their name on it.
The charge controller is marked as follows.
10A Advance Pulse Width Modulation (PWM) Charge controller:
- Automatic 12v/24v recognition (need 2 panels to run 24v systems)
- Fully 4 stage PWM charge management
- Day/night recognition
- Dual mosfet reverse current protection
- Protection from over-charging, deep-discharging and reverse connection from both solar panel and battery
- Protection from short circuit and over current
- LED indicator to show charging/fault/battery status/load status etc
- LED digital display to show the load work mode and status
- Self-consumption: 10mA or less
- Working temperature: -35C to 60C
- Working Humidity : 10% to 90% RH
- Size: 14 x 7.5 x 3cm
- Weight: 180 g
- Terminals for wire up to 6mm2
The solar panel is marked 10w
The QRP labs kit was connected to the GPS module, battery and a random bit of wire and placed in a plastic bag. I left it running 24×7 for 8 days and then checked the battery voltage.
The voltage showed 12.7 volts, I consider that to be a success.