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.

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.

Sunday, 20 November 2016


I do not have access to hi-speed data links such as fibre optics ("glasvezel") in my new QTH Zuidzijde near Den Bommel at Goeree-Overflakkee (QTH locator JO22dq). 6 weeks without TV was not that difficult, but it would be nice to see some moving pictures now and then.

I discovered that people in the neighbourhood use satellites to receive TV transmissions.

CanalDigital is a popular satellite TV-provider. I bought a satellite dish and satellite receiver from them. After installing the satellite dish and programming the receiver, now I am able to receive about 300 stations from which a lot transmit in High Definition (HDTV).

In order to receive the Astra3 satellite, elevation of the dish is 29.5 degrees and azimuth is 23.5 degrees east. 15 meter coaxial low loss cable connects the dual LNB to the M7 receiver.

Satellite dish installed

Astra3  (at 23.5 East) receive parameters

Off topic;

Lighthouse in Ouddorp

Ouddorp beach

Tuesday, 4 October 2016


Picture of our next QTH: Zuidzijde on the island of Goeree-Overflakkee:

QTH locator: JO21dq

View on the harbour of "Stad aan het Haringvliet", a village about 8 km from Zuidzijde:

Low-lying land ("polder") near Dirksland

Steamtram station Middelharnis

Tulip field in the vicinity of the water tower from Zuidzijde

Same tower (built 1934), view from our garden

Saturday, 11 June 2016

47 Amps Power Supply

Henny, PA3HK, had some used Hewlett Packard Power Supplies for sale. Yesterday I picked up one. It is a rather small unit (27 x 6 x 6 cm) and is capable of delivering 47 Amps (!) at 12 Vdc.
I made the small modifications to get it to work (3 jumpers installed and a 27 ohms resistor in the power supply of the fan) and now the unit runs fine.

I intend to use it for the 145 MHz transverter discussed earlier.

Tuesday, 17 May 2016

First 2m SSB QSO

First 2m SSB QSO realized with homemade transverter (See my blogspot article April 23)
Henk, PE0HZD replied on my request to make an USB QSO on  144.550 MHz.
Allthough our station distance (Zoetermeer Buytenwegh .. Oosterheem) is about 5 km´s it is worth to mention it..

Sunday, 24 April 2016


Last Wednesday evening there was a micromoon in a clear sky. A good opportunity to make some photoos. I found Jupiter in the constellation Lion.

                                                        Constellation Lion

Jupiter is the large dot left from the middle, the star Regulus (a blue giant) is on the right

The picture was taken from the 'silence area' near Weipoort. With an exposure time of 8 seconds and the light from the micro moon the area was captured:

Some amateur astronomers make beautiful pictures from the planets. For example Richard Bosman:
He made this nice photoo from Jupiter: