Exported OEM version of "Gakken MyKit 80". I was transfixed when I opened the box of this unit; everything was there! My old memory, stored in backup tapes somewhere in my brain, was reloaded into the main memory cells; I was in a sudden flashback of all of the scenes, experiences, persons I lived with, feelings and emotions related to this kit some 30 years ago. I again enjoy building various circuits including my favorite 2 transistor radio with this rewireable kit.

    Latest generation of electronics educational project kit offers 500 experiments including digital logic circuit and microprocessor. Its main workplace is a small breadboard therefore user can add any component needed for a project. Not only for myself to study electronics circuit, I use this in my workplace along with another 4 units to have a training cource for my associates who have never built radios by themselves. Back in my lab my EL500 is the main workbench for prototyping.

    Another electronics experiment kit made in Germany uses "Steckfedern" for circuit interconnection. The manual is an exellent textbook for electonics. The kit has 3 transistors, 1 Dualgate MOSFET, audio power amplifier, OP amp and other ICs, making this kit capable to perform more than 300 experiments. This kit is really challenging to me - the manual is written in German!

    Gakken revived the once very popular electronics experiment kit in 1960's through 70's. The mainstream EX-150 offers 150 variations of electronic circuits. Its neat look and easy operation is a gem although it has a certain drawback for a serious experimenter.

    Without prior knowledge of the content of this product I instantly decided to buy one for me, as its metal can package of this experimental kit was quite appealing. I would be overjoyed if my dad had bought me as a Christmass present when I was 8 years old, as I didn't have any electronic components in my hand to try.

    My guess to the contents of this box was almost correct --- a small prototyping board and components, with a good textbook. It includes 2 transistors,1 FET and a small meter, making this kit capable to perform more than 200 experiments. If there were some logic ICs and OP amps it would open to much wider world. What I miss here are a speaker, a tuning coil and a tuning capacitor to build a radio.

   

    As an early microcomputer user I still dream to build a machine by myself alone, but I would not be able to find time to do so and perhaps no longer practical. One day I read an news article about a newly developed small, inexpensive yet very promising microcomputer board called Raspberry Pi.

[This article is available in the "Research" section]

    Went to Akihabara to buy another Tanioka Electronic's graphic equalizer kit but it was sold out. It was the only item in my shopping list on that day. But at Akizuki they had a spring sale, selling miscellaneous electronic component assortment bag at 1000 JPY so I got two, which saved me from complete loss of time and transportation fee.
    Luckily one Parallax BASIC Stamp 2 OEM board kit was in there, I enjoyed my weekend building and testing it while seeing Pogo who had been suffering peunomia already for 3 days.

    Purchased in Stuttgart back in 2006 with general interest to PIC. However there was not enough time for it and no strong necessity, 2 years have quickly passed. Having an opportunity of 4 consecutive off days, my first Hello World with PIC was cerebrated with this programmer/experimenter board. Microprocessor programming is an exiting experience; I always see unlimited possibilities in this tiny world since my first 8080 processor.

    It has been perhaps 5 or 6 years since I found this kit - it would be useful to measure and control various things and would help my work in the lab. When I ordered a couple of analog panel meter to a Japanese electronics supply shop I found they also sell this kit so I ordered together. Assemble went quite smoothly with this high quality kit and it immediately became operational. Now its time for me to resume Windows programming.

    My very first soldering kit was this transistor radio, Although only 2 transistors are used, its reflex design is quite effective and stable, Even after 34 years it maintains clean exterior, sensitivity and plenty of volume; it is one of my relaxing time listing local news program with this radio of my first work.

    Building a practical shortwave radio is a challenge. This low priced shortwave reciever kit promises speaker reception with its C-MOS IC amplifier, but it is basically a crystal set plus RF and audio amplifier. Even if enough gain is obtained, selectivity will be the problem. How will it perform, and how the improvement will be made?

    This brand-new, German made, antique look radio receiver uses a real vacuum tube, intended to be an experimental / educational radio receiver which manual lists 30 experiments. It uses a 12AU7 twin triode and circuit is very much simple; regenerative detector plus single audio amplifier. The set has two tuning coils, for AM band and shortwave band, and one of them can be attached to the circuit. Dry cell batteries provide plate voltage, without any voltage converter; i.e. the plate voltage is only 12 volts. The regenerative control is a potentiometer simply varying the plate voltage of the detector tube. The sound from the headset (supplied) is extremely pure and clean - no transistor converter noise, no hum, no static. For local station listening this simple set is a gem. And there will be a lot of way to enjoy DX - first thing is to have a good long wire antenna.

    Another happy found in Germany is a vacuum tube shortwave radio kit which uses a combination of a tube, two transistors and an audio power amplifier IC. Its packkage box is made from cardboard with pleasant look mimicking a wodden case, which itself actually becomes the enclosure of the kit.

    (Coming soon)

    All of the items in the shop is priced 100 yen, approx. 85cents- this is the 100 yen shop. Now (year 2000) virtually every city and town in Japan has at least one of such shops. They also sell radio - yes, it is 100yen!!
Unbelievably, it is a 3 transistor and 1 diode superheterodyne with plastic tuning cap and IFT cans. Special high impedance earphone is used as the circuit does not have a power amplifier. The earphone is sold separately also at 100yen, making the total price 200 yen. This Chinese made radio shows enough performance if not in the mountain area. I would pay 1000 yen or even more, if this is a kit contains all of the unassembled components!

    Finally - a complete pocket radio for 100 yen! It is an extremely cheap looking pocket superheterodyne with 5 transistors. Even only taking out the speaker to repair another equipment, it's a bargain. And actually I did so. But after 10 years I started to revive this radio. Adding an external audio input will make this radio to be an powered external speaker so that I could use it while hiking in a deepforest mountain for bear avoidance.

    This is the first radio receiver kit Pogo built, offered at a hamfest as an edutainment activity for kids. Most of the components were already assembled exept 3 resistors. Pogo used a soldering iron for the first time, successfully soldered them, and the radio began to play with plenty of volume.

    This small aircraft receiver uses a varicap diode to tune. The original circuit required great concentration to tune in. Even if it could be made, the frequency soon detuned when the first syllable was spoken. Easy modification was to use "Heripot" precision potentiometer and separate battery to provide stable tuning voltage. Monitoring San Jose ATIS, Oakland control and Mountain View Moffet Field Automated Weather Observation was very interesting, but the receiver needs to be improved for a practical use.

    There are many vacuum tube amplifier kits in the market and I wanted to build one, but there are enough components in the lab to build a small audio amplifier. Why should I pay for a kit, when I have everyting in my stock? However I have been too lazy to start metal work to prepare chassis. Years simply passed without any result. On a day in this summer holiday week Pogo and Yome started to build small wood house model kits, I started to build this vacuum tube amplifier kit by Gakken, which has been stored for years.

    Elekit is one of the major electronics hobby kit manufactures in Japan. This unit is a surround audio adapter so that rear speakers can be hooked up to the conventional 2ch audio system. Circuit is a typical, simple matrix surround with power amplifier IC providing 1.5W of power per channel. Its quality is far superior than American kits; easy to build with illustrated manual, fine components and excellent print circuit boards. Enclosure is nice and pleasant, looking same or better than RadioShack products. Biggest problem is its expensive price!

    In 2010s I wanted to buy an analog graphics equalizer but none was available anymore as new on the consumer audio market. Tanioka Electronics was still offering variety of electronics kits including 8 pole graphics equalizer, so I decided to build one. After returning to the lab I found this kit was a single channel; I needed to buy one more for stereo.

    Exhausted with daily life, I really wanted to get a free time to relax without worrying anything - 8 hours would be just great. Today Yome and Pogo went to Granma's home and will stay there tonight - I pulled out a small LM386 audio amplifier board which I built a year ago intended to be a part of a homebrew reveiver. It has 2 LM386s so that stereo playback could also be possible. Thank God, I shall enjoy my favorite music on this opportunity with this cheap tiny power amplifier.

    To me the old kid the analog level meter is something indispensable to the audio equipment. However it has really became scarce to see them. So we decided to build one.

    Headphone output level of Toshiba X01T was not enough to drive the line input of the Mitsubushi Delica D:5's Rockford Fosgate Premium Audio System. This orthodox emitter grounded transistor audio amplifier was intended to boost the audio signal, in addition to a functionality of enabling the jack sensing of X01T.

   

    Found a mini audio power amplifier at 100 yen shop, I thought it would be useful if I use this to boost the weak audio of my PHS when I need to join a telephone conference in a noisy office.

    I guess all of the radio kids once experimented building their Wireless Mike. I assembled this unit after I returned to Japan; I wanted to enjoy my radio sets but Japanese AM radio stations were less entertaining. This small AM transmitter was expected to be a private radio station broadcasting my favorite sources. However the sound quality of this unit was quite poor. Main reason was the oscillator frequency changed as the audio voltage swung; after all, AM-1 was an FM transmitter as well! Tens of hours and more than $100 was spent to buy and read textbooks of oscillator and RF circuits before I could finally debug. What a good educational kit! Oscillator and buffer portion of the PCB was cropped, another circuit was newly built in a shielded case. Now AM-1 is running all day long, providing my favorite music with nice sound.

    This popular FM transmitter kit was expected to be my private FM station with which I could enjoy my favorite music everywhere in my home. The kit started to operate immediately after the build, however it was far less stable than expected. Frequency stability was something common to this class so it should be accepted, but strange distortion, noise and hum was hard to explain. This project therefore have been in unfinished state for 10 years - adding a buffer and using shielded case would cure the problem

    This simple and low cost FM wireless mike kit uses 2 transistors, and is well designed. Circuit board is in very good qualty, operation is stable and satisfactory. The purpose of building this is to hookup my small handheld transceiver so that the audio could be monitored by car FM radio. In-vehicle baby monitor function may also be useful.

    Small FM Stereo transmitter using New Japan Radio NJM-2035D Stereo Modulator IC. Circuit board is in high quality, building can be done smoothly, operation is stable and its audio quality is fine. Its designed frequency range was 76 to 86MHz; modified in order to tune to 88MHz and above, so that US version novelty FM pocket radio could be used. Stereo multiplexer & pilot signal circuit lacks filters; causing slight hissing noise. 7 years has passed after the assembly, a 19kHz bandpass filter was added which successfully eliminated multiplexer noise.

    While attempting to make Ramsey AM-1 operational, I strongly felt the necessity to learn the electronics principles. Learning, understanding, designing, building and testing a small AM transmitter will be a fun challenge for a radio kid such as myself.

    This small FM transmitter is intended for the cellular phone hands free operation- it can be attached to a cellular phone easily; its microphone picks up the audio from the phone speaker, transmitted to your car radio on the 88.9MHz FM.
Its crystall oscillator operates at 5th order harmonic to generate the FM signal, however the other harmonics are radiated equally, including 124.421MHz which resides just in the middle of the air band.

    Fearing of our new 1995 Honda Civic being stolen, this microwave motion detector was planned to be installed on the garage. However it never worked correctly so the project was soon abandoned. It might be interesting to resume debugging, but it may just find the apparatus being a mere microwave noise generator...

    Using two MF8 switched capacitor filters, this unit is an audio filter aiding the CW reception; connected between communications receiver and a speaker. Building was easy and no adjustment or modfication was necessary in order to make it a practical unit. It worked just fine to me, so I gave it the dedicated case which looks nice. Modern receivers commonly employ DSP filters, but using such analog filter is also fun especially if it was built by oneself.

    This unit is called an Introductory Modem for Packet, designed by N2YMW and introduced on QST Dec.1995 issue. Print circuit board was purchased from Far Circuits. The unit uses TCM3105 FSK modem IC, power is supplied from PC via RS-232C port. Although no obvious problem with this unit or design, my project was suspended and awaiting to be completed.

    Participating amateur radio contests on 50MHz SSB requires continuously calling CQ for hours unless you occupy one of the most optimal operating locations, therefore a voice keyer is desired. This small, low cost voice recorder kit employs an APR9600 Voice Recording IC which is capable to record and playback a voice message up to 60 seconds at 4.2kHz sampling, or 30 seconds at 8kHz sampling. The quality of this kit is excellent, easy to build and it started to operate without any problem. In order to make it a practical voice keyer for a SSB transeiver, further interface circuit should be prepared, which will be a fun and rewarding project.

    As an amateur radio station, antenna projects must not be avoided. Here a middle aged ham resumed his summer vacation homework which he failed some 28 tears ago.

    The IPF Blinker Position Lamp Controller installed into the YAMAHA TDM850 failed in just 1 year. Buying the same or similar thing again wasn't a fun idea, so I decided to build one.

    With handle cover equipped the grip heater of the Yamaha TDM850 became too hot. But if the heater was tuened off it was too cold for palms and fingers after 1.5 hours of highway riding in a deep winter night. So there was a need of adding a grip heater dropper, so that it could be at confortable temperature.

    One of the lab's activity is to participate the "Econopower Race" - the fuel efficiency competition of the gas-powered vehicle. The team suffered budget problem and no further costly improvement was possible. In order to find out the best driving pattern, a vehicle speed logging system has been developed which uses minidisc recorder and homebrew interface unit. Special software has been developed to analyze WAV files into vehice and engine speed data.

    Akizuki Denshi is famous with its original electronics kits; mainly aimed for intermediate to advanced kit builders. Here is an easy Sealed Battery Charger Kit, which I plan to use to charge my bike's headlight battery.