Sunday, 24 December 2017

Teylers museum

Some collections are special and deserve to be maintained. 

The collection of Mr. Teyler from Haarlem is such a special collection. This week we visited the Teylers museum and were able to see interesting items such as Leyden jars, 19th century light bulbs, ancient skeletons and the study room of prof. Lorentz.

More info:

Leyden jars

Oval room

Collection 19th century light bulbs

Paint art

Neanderthalers' jaw

Sunday, 10 December 2017

uBITX kit available

A DIY kit for the HF general coverage transceiver uBITX is available:

Off topic:

                                              'Waterbus', view from Zwijndrecht

Friday, 24 November 2017

73 from Banja Luka

A nice eQSL-card was found in the postbox today.
An SSB 6m QSO made August 2008 was confirmed by Vlado from Bosnia Herzegovina:

Off topic:


Wednesday, 11 October 2017

Medium Wave receiver

This is how a Japanese design of a Medium Wave receiver looks like:

And this is how it looks like as a $5 DIY kit:

Off topic:

Suriname river, Paramaribo 2018 

Saturday, 9 September 2017

Satellite TV

Today I kept track of the signal strength of the satellite TV signal from the satellite Astra 23.5 (Astra 3B transmits just above 11 GHz).

It was interesting to see that a dip in the signal strength came with the bad weather that arrived from the North Sea;

Presentation of rainfall App 'buienradar'

TV screen with sat parameters

Monday, 4 September 2017


I downloaded KiCad version 4.0.7 which is an open source Electronics Design program. With the schematic editor you can create your design without limit; there are no paywalls to unlock features. An official library for schematic symbols and a built-in schematic symbol editor are available.More info here:

The first schematic with this program:

Off topic:

Paramaribo January 12, 2018

Friday, 25 August 2017

Twin diode receiver

This radio uses two receiver chains; the supply voltage needed for the transistor amplifier is generated by a strong local broadcast station to which diode receiver number 1 (left side of the schematic) is fix-tuned. Tune with the aid of a meter and adjust for maximum detection. Low-level stations are detected with the diode receiver number two (right side of schematic). Use a germanium low signal AF type transistor (AC151, 2SB187) and Ge-diodes (AA119, AA112, AO85...). Design coil1 and 2 in such a way that Medium Wave broadcast stations are received.

A supply voltage as low as 450 mV produces audible signal amplification. Of course you have to use TWO antennas.
The designer of this radio uses for receiver number 2 (right) a loop (frame) antenna, for receiver number 1 (left) a a 20 meters outside antenna (wire). 

Receiver 1 generates a supply voltage of approx. 900 mV under load of receiver number 2.
Adjust the variable 250 kOhms resistor to approx 50 % of the voltage generated by receiver number 1 voltage (measured at + pole). Best value for 10 kOhms trim pot is 3 to 6 kOhms.

Do not use electrolytic capacitors for the 0.1 uF capacitors. Do not forget to install the 1 nF capacitor. Attention for the polarity of the diode (AA112, AO85, AA119...) in receiver nr 1.


Off topic:

Canal in Den Haag (Zuidwal / Dunne Bierkade), 7 Sep.  2017

Monday, 21 August 2017

QRP labs 5W CW transceiver kit

Hans Summers, G0UPL, has developped a new transceiver:
It is a mono-band 5W CW transceiver, with tons of features, including WSPR beacon, built-in alignment/test equipment, iambic keyer, CW decoder, rotary-encoder tuned synthesised VFO, and more. Price is appr. 42€. The kit is available for 80, 60, 40, 30, 20 or 17m bands and can be ordered here: .
The 137-page assembly/operation manual can be downloaded here and includes circuit diagram and comprehensive description of circuit operation.

The transceiver has lots of nice features:

+ Easy to build, single-board design, 10 x 8cm, all controls are board-mounted
+ Professional quality double-sided, through-hole plated, silk-screen printed PCB
+ Choice of single band, 80, 60, 40, 30, 20 or 17m
+ Approximately 3-5W CW output (depending on supply voltage)
+ 7-16V recommended supply voltage
+ etc. etc.

Off topic: Vintage cars on Goeree-Overflakkee

Citroen HY in Oude Tonge
Truck in Achthuizen

Used car in Greece, Epirus (holiday 2013)

Friday, 21 July 2017

Radio Veronica

Radio Veronica was an offshore radio station that began broadcasting in 1960. The station transmitted from the North Sea for over fourteen years. It was set up by independent radio, TV and household electrical retailers in the Netherlands to stimulate the sales of radio receivers by providing an alternative to the Netherlands state-licensed stations in Hilversum.

It must have been around 1973 that I could receive Radio Veronica with a diode receiver (similar to the 'jampot' receiver below) from the middle of the Netherlands. I had to use a 20 meter longwire antenna to listen to  Radio Veronica.

Broadcasts began on 21 April 1960. 
Used medium wave frequencies were 1562 kHz (192 meter) and 557 kHz (538 meter). 
The station announced itself as VRON (Vrije Radio Omroep Nederland; Free Radio Station [of the] Netherlands) but changed to Radio Veronica, after the poem "Het Zwarte Schaap Veronica" — The Black Sheep Veronica — by the children's poet Annie M.G. Schmidt.

The station's closure, some of its staff applied for a broadcasting licence and continued as a legal organisation with the same name. The original Radio Veronica became the most popular station in the Netherlands. It broadcast from a former lightship Borkum Riff and anchored off the Dutch coastline. 

The ship was fitted with a horizontal Medium Wave antenna between the fore and aft masts, fed by a one-kilowatt transmitter. Most of its programs were recorded in a studio in Hilversum. At the end of the 1960s the studios and offices moved to bigger premises in Hilversum. Initially advertisers were reluctant to buy airtime, but those that did reported increases in sales and gradually the station's revenue improved.

For a short time the station also ran an English language service under the call letters CNBC (Commercial Neutral Broadcasting Company). Although short-lived, CNBC was presented by professional broadcasters who were able to give invaluable technical advice to Veronica's Dutch staff.

Monday, 26 June 2017

73 from Jakarta

Tata YB0EIN from Jakarta, Indonesia sent me this eQSL from an RTTY QSO back in 2006:

Off topic:

Dragonfly in my garden. This one has a length of appr. 10 cm

Waterspout near Zuidzijde 18 Sep 2017

Zuidzijde 1936

Wednesday, 7 June 2017

Tube headphone amplifier

Finished a nice DIY kit. This time a tube headphone amplifier.
The two 6J5 triodes look fine !

                              Headphone amplifier with two 6J5 triodes

After the triodes, low noise ic's NE5532P take care for more amplification.

Now I just have to find a simple power supply unit capable of delivering +/0/- 15VDC to get it to work.

More info:

Circuit of the amp;

Off topic:

View of the "Sint Lievensmonstertoren" in Zierikzee.

Zierikzee is the capital city of the island of Schouwen-Duivenland in the province of Zeeland; the island just below the island where I live, Goeree-Overflakkee.

Sint Lievensmonstertoren, Zierikzee

The start of the construction of the tower was in 1454. The original design shows that the final height should have been 130 meters, but due to a lack of resources this value was never reached. 62 meters is the height at this moment. Nevertheless an amazing achievement of the people in the 15th and 16th century.
Zierikzee harbour

Zierikzee visit, June 28, 2017 

Thursday, 1 June 2017

Greeting from Port Elizabeth

Just received a funny eQSL-card from Barry ZS2EZ in South Africa (Port Elizabeth).
QSO was from 2011 on 28 MHz (RTTY).

Off topic:

Photo taken through a Boeing 737-900 window from Goeree-Overflakkee;

Thursday, 11 May 2017

Radiomuseum De Stove in Achthuizen

I found that only a few km’s away from where I live, there is a tiny radiomuseum called "De Stove" in the town of Achthuizen. Owner and builder Jan Dekkers has collected tube radios for many years. In his collection one can find one- and two-valve (‘lamp’) radios, lots of Philips tube radios, home built devices and even a small AM transmitter. The art deco interior and nostalgic decoration of the museum takes you back in time.

The address of the museum is Achthuizensedijk 12, Achthuizen (The Netherlands). Opening times are 13:00-16:00 hr. each Saturday afternoon.

Interior radiomuseum "De Stove"

Founder Jan Dekkers

Medium Wave receiver

Attic of the museum

 Home built 2-valve radio

 Home built AM transmitter

Collection Erres radios

Achthuizen (Goeree-Overflakkee)

Published in "QRP Nieuwsbrief" Nr. 162, June 2017

Monday, 27 March 2017


Ashar Farhan has developped a compact HF transceiver with following characteristics:

- 10 Watts PEP on lower HF bands
- SSB and CW
- Minimal controls
- Based on Arduino controller and one Si5351 for all local oscillators
- Double conversion, high IF superhet architecture
- Easy to build, low priced components used

Enjoy his article:

And the interview

Friday, 24 March 2017

USB Microscope

In order to be able to do visual inspections of PCB’s or components I normally use a magnifier glass. Where the magnifier glass offers a magnification of 5X, a low-cost USB microscope can give you 20..500X.
The USB microscope I ordered for about 15 euro gives interesting results. It contains 8 white LEDs that illuminate the object to be investigated from above. The focus range and magnification can be adjusted.  LED Light intensity can be changed. It really turned out to be a plug-and-play device. Plug in the USB connector, install the software and enjoy the pictures (and even moving images). Great fun.

USB Microscope set-up and PCB:

Dove's feather

5 cents Euro coin

 Sanding paper

 30 pF capacitor

Off-topic; tulip fields, April 2017, 100 meters from our backyard

More off-topic;

Flypast of Beechcraft D18S and a Harvard April 22, 2017 in Stad aan ‘t Haringvliet as a contribute to the Irish pilot Thomas Noble Forster who crashed, at the age of 21, in het Haringvliet April 1943.