Thursday 30 November 2023

Solar flare hitting Earth

A powerful M9.8-class solar flare erupted from the sun (AR3500) on Wednesday (Nov. 29) at 2:50 p.m. EST (1950 GMT), hurling a super-hot plasma eruption known as a coronal mass ejection (CME) toward Earth. The flare is expected to hit Earth today (Dec. 1, 2023).

Hopefully our internet and radio communication systems can withstand the amount of electromagnetic energy that is brought in by this -almost X-class- solar flare

Note: I have not heard of any damage to communication systems whatsoever.

Monday 30 October 2023

DvdR 2023

Last Saturday, Oct. 28, I was part of the ‘NL-post’ team at the DvdR (Day of the Radio Amateur) in Zwolle, IJsselhallen. 

I was there with Thieu, NL-199, PA0M and Gerard, PA2G. It was good to speak to fellow radio enthousiastics and see lots of old and new radio stuff. It was remarkable that my homebrewed  BITX20 from 10 years ago - built in ‘Manhattan style’ - draw a lot of attention.

NL-Post stand with PA0M and PA2G

Scouting girls making worldwide radio contacts during CQWW SSB contest

Nice antenna designs

My BITX20 caught some attention

Monday 26 June 2023

SDR receiver exploration

Great fun with SDR Receiver MSI2500 in combination with SDRuno software. I am exploring  the possibilities of this nice toy.

The SDR receiver (frequency range 30 - 1000 MHz) has 5 antenna inputs each with its own bandfilter

SDRuno software in action ( Repeater PI2NOS, 430.125 MHz selected)

Experiment with E-field antenna for low frequency signals (< 10 MHz ).

I wrote an article for the Dutch radiomagazine Electron, NL-Post, Nov. 2023, about this SDR receiver:

Saturday 10 June 2023


Yesterday evening I witnessed the sunset from my backyard garden.

I realized that it is amazing that a star at a distance of 150 million kilometers from us affects the propagation of radio signals on earth. During daytime the solar wind presses the Kennelly-Heaviside layer closer to the earth, thereby limiting how far it can reflect radio waves. The effect is also influenced by the amount of sunspot activity.

Sunset yesterday from Zuidzijde

Tuesday 6 June 2023

HB9 on 160 m

For a change, last week I was active on 160 m. With my end-fed longwire antenna  - in the evening hours  - I managed to work a couple of stations. One of them was HB9EFK. This was my first with Switzerland on 160 m.

Note: Description of the balun I use in combination with 25 mtrs of longwire 

Monday 8 May 2023

Start of the Es season

Yesterday I powered up my 4 m equipment. To my surprise I saw EA and 9H stations. No dx  QSO's yet. I did make some local 70 MHz QSO's though. Looks like the Es season is ready to start.


70MHz stations that heard my 15 Watt signal 9 July 2023. With some of them I had a FT8 QSO;

First with OK;

Monday 17 April 2023

The Stele of Hatiay

Lately I visited the National Museum of Antiquities (‘Rijksmuseum van Oudheden’) in Leiden. One of the many fascinating objects that amazed me was ‘The Stele of Hatiay’. It shows general Hatiay announcing – in name of his king - that he has established many new sacred memorials (1330-1320 BC). That’s what the text near the stele tells us.

I was intrigued by the triangular shaped device that Hatiay holds in his hand. If you have a close look at the smaller persons, some of them also hold similar devices. In my view the triangular shaped units look like microphones. With a little bit of phantasy we see here something that looks like an early version of an internet teams meeting… Maybe the microphones operate wireless since there is a small piece of (antenna) wire coming from the triangles…

More interesting information on ancient technology:

Friday 7 April 2023

BC860XLT VHF/UHF scanner

Last weekend I re-discovered the Uniden Bearcat BC860XLT VHF/UHF scanner. I did not use it for over 10 years. It is a remarkable receiver covering the frequency range 29 – 956 MHz. It contains 100 channels to store favorite frequencies.

I was glad to find out that the device still works fine. Receiving aircraft AM voice transmissions from Rotterdam Airport and vessel voice communications from the Northsea confirm that the unit is in good shape. Nice toy !



Friday 10 March 2023

Citizen Band QSL card

Just found one of my old CB QSL cards. This one is from 1978. At the time I used a 23 channel CB transceiver "North Star". 14,    27.125 MHz  AM .. and 4 Watt RF output into a DV27 mobile antenna.

How did your QSL card look like ?

Friday 16 December 2022

Logaritmic Power Detector

From AliExpress I ordered this nice PCB with a logaritmic power detector circuit onboard. The electronics is designed around an AD8307 integrated circuit. The detector should operate in the range 1 - 600 MHz. DC input anywhere between 6 .. 15 Volts. 

All ingredients are there to realize a nice S-meter / RF Pwr-meter.