OLD PROJECTS
(1963-1982)

KLIK HIER VOOR DE NEDERLANDSE VERSIE

This story is about the beginning of the radio hobby!


The radio hobby really started with this Philips EE8-EE20 construction kit!

EE8-EE20 construction kit
It started with the well known Philips EE8-EE20 construction kit for all kinds of electronic projects. It was approximately in 1963, when I was 10 years old. This construction kit was sold during the years 1963-1966. It worked with a system with springs on a piece of wood with holes.


It worked with a system with springs
on a piece of wood with holes.

The radio project was my most favourite project of this construction kit!


The radio project was my most favourite
project of this construction kit !

This radio is a so called reflex circuit. The AF116 does not only amplify the RF signal, but also the detected audio signal. The diode detector with an OA79 does only work because a germanium diode does have a considerable leakage resistance. Detection performance is quite dependent on the leakage resistance of this diode. The loudspeaker is a 150 ohm type.


The diagram. The diode detector can only work with a germanium diode
because of the required leakage resistance that such a diode has.

With an own wounded coil, it was possible to receive the coast stations and ships. The radio virus did never go away anymore! Also the morse code generator with key was very interesting! Quite soon I did practice much with the morse code and could already send all the characters!


The morse code generator with the simple key.

I did get a soldering iron and the "SUPPLEMENT" radio was made.
I did get a soldering iron and the SUPPLEMENT radio from the book "boys radio" was made. This was also a reflex receiver and it had the famous 402 coil. My portable regenerative receivers that I built 30 years later were based on this diagram! It was possible to receiver coast stations and shortwave stations when shortening a part of the 402 coil.

The supplement receiver was the first soldering project. It worked with a kind of blind rivets that you had to hit in the holes of a pertinax board with a hammer. The electronic parts were soldered in the blind rivets.

The tube radio "ATOM" in the same book was built.
The ATOM receiver was the first radio with a tube. It was a small 7 pin tube for use with batteries. This receiver was not as good as the SUPPLEMENT receiver with 1 transistor, the regeneration control was not so smooth. But it had a good medium wave reception. Unfortunately, this receiver had a very short life. I made a mistake and exchanged the 1.5V battery for the glow wire with the 12V anode battery. A short flash and the tube was dead. There was no money for a new tube...

The ATOM receiver was the first radio with tubes. It was a small 7 pin tube for use with batteries. The anode voltage was 13.5V (3 flat batteries in series) and the glow wire voltage came from a fat 1.5V battery. My pocket money was not enough to feed this battery eater...

Illegal transmitters.
Of course I made some illegal transmitters. The medium wave transmitters did have a very bad quality, the antenna was a wire of 6 meters long just under the roof. But it was still possible to make contacts upto 10 km distances and the reception was good upto approximately 3 km.


The two medium wave transmitters. Stability was bad. A wire
of 6 meters length just under the roof was used as antenna.

Also a few FM transmitters were made. They worked in the then not used frequency range of 100 to 104 MHz. At that time there were no other illegal FM transmitters. They were all on the medium wave.


The simple FM transmitter with whip antenna had a range of approximately 1 kilometer.


The FM transmitter with extra final amplifier and dipole antenna had a larger range.

The illegal period lasted only a few months.

The first amateur receiver.
The first amateur receiver was with an EC92 triode and a crystal telephone. It was made for the 80 meter amateur band and many amateurs could be received in SSB. I could not decode Morse yet.


The 80 meter receiver with EC92. The 150 volt zener
diode is given the diagram but never installed.

This receiver was built in 1973. I still know that because all amateurs said "Best 73" to each other. I had expected that after the turn of the year it would become "Best 74"...
An extra LC circuit was added between the antenna and the receiver to suppress the strong signals of 40 meter broadcast stations. During the evenings, these will cause whistles in the reception. There are two variable capacitors for the tuning, one for the coarse tuning and one for the fine tuning.
I also modified a medium wave tube radio for 80 meters and later an old radio with red coloured tubes, that could receive the whole band of 1.5 to 4 MHz. A BFO with a transistor was installed in this radio. This BFO on 455 kHz was less stable than the tube radio... Unfortunately there are no photos of these receivers left.

The first amateur transmitter.
The first amateur transmitter was constructed in 1976 and 1977. This 2 meter transceiver could transmit in FM and CW. For the reception of CW signals, the 5.5 MHz IF signal was connected to a Drake SSR1 shortwave receiver. Many FM and CW QSO's were made with this transceiver and also RTTY contacts with an old, heavy and noisy telex.


The first amateur transmitter was a home made transceiver for 2 meter.
For CW, the 5.5 MHz IF signal was connected to the SSR1 receiver.

RF equipment.
In 1978 a CW transceiver was made. The output power was approximately 5 watts and it could transmit on 80, 40 and 20 meters. The receiver was a direct conversion receiver. Many QSO's were made with this QRP transceiver, also portable. In 1999 this transceiver was completely modified. You can find it somewhere on this website. I also had a TS520 with a very good CW filter.


The homemade CW transceiver.
In 1999 it was completely modified.
It had an excellent CW filter with 88mH coils. Therefore, it was also very sensitive for 50Hz magnetic fields of transformers.

The first computer.
The first computer was bought in approximately 1980. It was a kit, the Acorn Atom and it costed a fortune. Programs were stored on cassettes and a small black and white TV was used as a monitor. The clockspeed was 1 MHz and it had a 6502 8 bits microcontroller inside. There was ROM memory and 8k RAM memory that later was expanded to 16k. I also made an option to put eeproms in a holder. Then it was not necessary to load the programs from the cassette, they were in the 4 k eeprom.


Computer from the time that they did still run barefoot! It was
the Acorn Atom. A small black and white TV was used as monitor!

The big advantage of the Acorn Atom was that the documentation was excellent. It was programmable in assembly and a kind of basic. This computer was used for the reception of RTTY (telex) and the transmission of CW. I had many other programs like tone generators, frequency counter, propagation prediction, moon and sun postions, a simple text editor and many others. And it had a real advantage compared to our modern computers: it was ready for use directly after switching it on, only the eeprom type 2716 or 2732 had to be exchanged sometimes!!!

Portable with low QRP power.
In 1977, I became active on the HF bands in Morse code as that works so good with weak signals. To work Portable with low QRP power (only 1 watt) on all kinds of places and weather conditions became a real hobby. This happened with simple homemade CW transceivers with VXO tuning. Especially the simplicity of these small transceivers and the possibility to make so many QSO's with such low power, were very interesting. It was a huge difference compared to working in the shack with the TS520 and 100 watt RF power. How varied is our hobby!!!

Radiosilence from 1982 to 1996.
From 1982 to 1996 there were (almost) no radio activities. There were other hobbies like sailing. I did make a depth sounder with LED bar display and two receivers for weather forecasts and navigational warnings of coast stations.
In 1996 I started again with making a new shortwave receiver. This receiver and other projects after 1996 can be found on this website.

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