The contributions presented here cover the various projects I have built using the Philips EE system based on the collection I gathered throughout more than twenty years:
Here I provide for all design information (electronics diagram, layouts etc.) as well as information on experiences, improvements etc. that may be useful to other enthusiasts of this system. You may click on the title or "read more" to read the full article. Enjoy!
The three-transistor MW receiver (nr. 5.02) has likely been one of the most popular designs in the Philips EE series. This radio was depicted on the boxes of the EE2000 series of kits, it was a very successful design that always worked well and did not need an external antenna. It is a so-called "reflex" design, which means that the first amplifier stage is used for both HF and AF signal amplification, as the rectified signal is fed back to the same amplifier.
Although it is a simple, proven design, I wondered in which ways this beautiful receiver could be improved whilst not comprising its reflex concept. It turned out that there were several opportunities that were discussed with and contributed by the active Philips EE community at rigert.com :
- On component level, here are the "low-hanging fruits" that already improve reception:
- Adding a second rectifier diode (replacing the 10 kOhm resistor) for a stronger overall reception (as the two diodes now work as a voltage doubler).
- Reducing the capacitor in the rectifier circuit for 0.1uF to 22 nf for improved and stronger audio (due to a better RC rectification time constant).
- On board design level:
- Re-arranging the audio section such that the volume control is in between the two audio stages instead of before them, to avoid mechanical noise from the audio potentiometer to be strongly amplified.
- On electrical circuit design level, investigating the following two alternatives (both of which are described in the subsections below):
- Adding regeneration (but that implies an additional control for tuning).
- High-impedance RF-input buffering for improved signal reception, for example using a FET-buffer or a emitter-follower circuit.
Although many European and American shortwave (SW) stations have disappeared, there is still quite some activity from more distant, South Asian stations that now have room to be received as well with simple, sensitive receivers.
The EE2003 SW receiver (5.03) can be upgraded towards a more sensitive and controllable design by adding explicit regeneration control outside of the RF-part of the circuit, as I have described here. In that article I show that by controlling the DC Collector-Emitter voltage difference of the RF transistor via the RF-choke using an external potmeter, the receiver can be used to receive both AM stations (at maximum sensitivity just before onset of oscillation) and SSB stations (in oscillating mode, providing the required beat note).
Here follow the key design files for three variants of the same design. The picture here shows the actual layout for the 5.8 - 10 MHz receiver (49m, 41 and 31m bands):
This page describes a powerful MW receiver based on two non-EE components (SA612A mixer+oscillator and MK484 radio ic used as a IF amplifier+detector):
There are a two variants of this design:
- A variant with two red IF coils. This design can be built using a single EE2005/1005 kit , and the SA612A (or SA602A / NE612A / NE602A identical variants) as well as the ZN414 or MK484 AM radio chip
- A variant with three red IF coils (shown in the picture above). This version requires an additional EE2005/1005 kit for the extra IF coil (see Ebay, marktplaats.nl etc.)
Tor Gjerde has published his .fig templates for generating breadboard layout files. I have used these extensively to give my projects that official Philips EE look that is virtually indistinguishable from the original Philips EE versions. His templates are published on his website: Link Tor Gjerde . These published templates as well as his EE2003 diagrams are in XFig metric size units. He appears to use XFig for creating his diagrams, not WinFig - which I use.
Regarding WinFig (MS-Windows) - XFig (Linux) interoperability of files it appears that the use of the Imperial instead of Metric units has the advantage of giving exactly the same results on printing, whereas in Metric format a correction is needed when WinFig is used. The background is explained by the author of WinFig (Andreas Schmidt) in detail on his FAQ page under the section "Drawings that were created with Xfig using metric units (cm) are slightly smaller in WinFIG". As a conclusion he states: "You can avoid all that trouble by using imperial units only".
Therefore, here follow the links to the Imperial versions of Tor Gjerde's template files (which he does not publish in the mentioned link but which I received from him):
- Grid with battery and numbered external connection positions
- Various components
- Transistors in various orientations
- Resistors in various orientations
- Capacitors in various orientations
- Coils in various orientations
- Trimming potentiometer (is now part of the "Various components" file)
- ICs from the EE 2001 series (including an extra DIP8 variant)
In addition to these, I derived two extra templates:
The panel design of the capacitance knobs can be redesigned by using the following MS-PowerPoint template (print to scale): PPT-link
The template provide for the design of scales that look as follows:
In practice this template may be used to give a lighted scale as shown here (in this case using LED's in E10 fittings, see discussion below):
I always wanted to try to get to fit the EE2010/13 FM-receiver with touch controls on a single (14x12) breadboard. And I managed as well:
This receiver has both its volume control (potmeter right) as well as the regeneration level (potmeter left) on the board itself, the only external components are the battery connection (with on-off switch) and the loudspeaker. The receiver is tuned (+) (-) by pressing the switches, in idle mode it stays at the selected frequency. This receiver is remarkably sensitive, no antenna is needed.
The EE2016 Ultrasonic converter circuit needs only some minor tweaks to turn it into a very useful bat detector. Furthermore, the circuit has several interesting aspects that are not covered in the manual and therefore warrants a separate discussion. The picture below is my implementation and it is discussed here in detail.
This bat detector circuit is based on the original EE2016 4.7.14 circuit ("Ultraschall-Konverter" - Ultrasonic Converter), with the following small but meaningful improvements:
- Compact layout design made for one Philips EE board instead of the original two boards, as shown above
- Improved oscillator circuit (T1/T2),
- Increased sensitivity by reducing a few resistors values, and
- Large capacitor added in the Vcc line for better stability.
Although the EE2016 ultrasonic bat detector as published on this website works quite well (using the kit's 40kHz transducers), I felt there was potential to improve on both sensitivity, frequency range and functionality. Since I am fond of using the SA612A (NE602A) mixer chip (see the superhet radio), I stumbled upon Bertrik Sikken's analog design for a bat detector and extended it with a broad-range MEMS-microphone (20 - 120kHz), a different audio circuit (based on the TDA7052A) and a microcontroller (PICAXE-08M2) to allow for a LCD/OLED display and an automatic frequency sweeping mode. The initial setup is shown here, which reveals that another goal was to see how designing my own front panel for the EE1000 works out in practice:
The resulting device is actually performing very well, also through the help of many contributors (see links below) and I can really recommend building it (but then please check these links). Note that one can easily exchange the audio circuit and the microcontroller type with another one that suits better.
Here follows more information on the latest versions of the design and the discussion links:
As your Philips EE system starts to age, this often becomes apparent through the following two symptoms:
- The transistor PCB's are getting to look worn down
- you wish to use more modern and very useful components, like LDO's, the ZN414 / MK484 radio chip etc. etc. .
In those cases you may want to make these components mechanically suitable and having the appearance (again) of a new Philips EE component. For that reason I developed a MS-PowerPoint file with templates for stickers with the following very typical Philips EE look:
Please feel free to download the PPT file below and make your own adaptations as you see fit. The file contains also a few hints on how to print properly (scaling need, type of sticker paper etc.). Apart from a pair of scissors, a small, very sharp cutting knife is useful here too ... .