Thursday, 12 September 2019

Sunday, 1 September 2019

Use of digimodes on 319 THz

I enjoyed building a simple infrared transmitter and receiver.
The circuits are designed around IR LEDs using a wavelength of 940 nm (frequency 319 THz).
On this high frequency it was simple to transmit and receive SSTV pictures, over a long distance of 30 cm, as you can see below:

It is a first trial and a lot can be improved.

Picture transmitted

Picture received

Great fun with this interesting DIY kit (3 euros)

How about using a 5W IR LED ? Or other digimodes. I already used FT8 succesfully (Am I the first using this digimode on this high frequency :-)  )

Thursday, 29 August 2019


To commemorate the 60th anniversary of the launch of SS Rotterdam, a special call and eQSL for PA60HAL are introduced:

Friday, 9 August 2019

Weather station

The Alecto WS-4800 weather station that I installed provides interesting data about the local weather.

The station consists of an indoor and outdoor unit that communicate over a 868 MHz datalink.

The outdoor unit was easy to install:

The indoor unit provides besides weather data also the local time and date via a DCF77 receiver. Interesting weather parameters are baropressure, dewpoint temperature, pressure trending, windspeed, winddirection, moonphase, rainfall.

Thursday, 1 August 2019

ADS-B receiver

I have been able to capture aircraft flying above me by receiving their
ADS-B 1090 MHz signal via the discone antenna on the roof.
For this purpose the TV dongle is used in combination with the RTL1090.beta3 software.

All the "ins" and "outs" of ADS-B (Automatic Dependent Surveillance Broadcast) can be found on the internet. For example here:

Now I can watch "real-time", without internet connection, the aircraft flying above the
island of Goeree-Overflakkee. Maybe further, I saw signals 100 km's over the North Sea.

Sunday, 28 July 2019

DVB-T TV dongle as Wideband receiver

A couple of years ago I had good experiencies with a TV stick as broadband receiver:

This time I used a Terratec Cinergy Tstick+ running under Windows10 to setup a receiver capable of receiving signals in the range 50...1800 MHz (RTL2832U chip / R820T tuner)

The latest version of SDR#Stable from via was installed. Also zadig24.exe was used to install the proper driver.

The dongle was connected to my discone antenne. I have been able to receive narrowband 2m, 70cm and AM airband transmissions so far. Example of 70 cm signal:

Repeater of Goes, received at 430.075 MHz.

Thursday, 18 July 2019

Geekcreit GHz Signal Generator

Geekcreit offers a nice signal generator board for appr. 30 euros with microchip ADF4351. Frequency range 35 MHz - 4.4 GHz (!)


With OLED display
Host computer USB & serial port
Integrated key operation
Good man-machine interface
Many improvements on the phase noise, phase spurious and loop filter
Module has 35 MHz - 4.4 GHz frequency output, point frequency, sweep, frequency hopping and other basic functions
Dimensions: 88mm * 67mm
Power supply: 5V-15V (DC 5.1MM); 5V (USB)
Bandwidth: ADF4351: 35MHz - 4.4GHz; ADF4350: 137MHz - 4.4GHz
Module step: 100KHz(min)
Frequency error: ± 1KHz
Output: OUTA OUTB two way
Module phase noise: better than -100dBc @ 10KHz (noise is different with different band phase)
Module output power: 7dBm (MAX)
Module interface: The external communication port of the STM32 USB can be configured to USB or analog serial port (in default)
Module program download mode: SW module, three-wire system (GND SWCLK SWDIO)


Visit to the city of Gent, Belgium, July 31st, 2019

Friday, 21 June 2019

First Transatlantic 144 MHz contact

A historic contact was made on Sunday the 16th June 2019 when the Atlantic was spanned for the first time on 144 MHz.

D41CV on Cape Verde Islands off the coast of Africa managed to work FG8OJ in Guadeloupe on 144.174 MHz using the FT8 digital mode. The distance was an incredible 3,867 kms.

Sunday, 9 June 2019

Rotterdam Tramway Company

The RTM (Rotterdam Tramway Company) Museum in Ouddorp houses a collection of steam and diesel locomotives, as well as beautifully restored carriages and goods wagons, of which some are still in use today.  
You can wander round the depot and admire the old post van and the last surviving camping coach.

I made this photo of the tracks:

Steam tram from 1906:

Diesel tram inside the depot:

Monday, 3 June 2019

First 2m QSO with UK

After completing the prototype of the interface circuit I was able to operate with FT-8 using the almost 40 year old FT-480R transceiver. June 1 I made some FT-8 contacts of which the one with Mike, G3YPP (QTH loc. JO02rv) was quite interesting for me, since this was my first 2m QSO with UK on 144 MHz (using a modest discone antenna at 4 meters above sealevel and 5 Watts RF).

Protoype interface: