About 100Yen shop and 100Yen radio

 

"100Yen radio".... was sold in this package
at "100Yen shop" at price of only 100Yen

Recently there are many "100Yen shop" in Japan ,at where many many kinds of merchandizes are sold. Many of them are sold at same price of only 100Yen (about US$ 0.95)  . We can also buy tools and some materials for making radio, like screw driver, nipper, pliers, drill, acryl plate, wire, and so on. Electronic parts are not sold but some merchandizes containing electronic parts (small speaker box, clock, ear phone etc)  are sold. 

And once at 100Yen shop, 3-transistor suprt het radios are sold. Of course, Price of them are also 100Yen. When this radio appeared in 100Yen shop, many radio amateur surprised because 3-transistor super het uses many expensive parts for this sort of cheep radios and need complicated adjustment.
It contains many useful parts for radio amateur, like IFTs, OSC, 2-gang variable capacitor, switched volume control ...and so on. Japanese radio amateur called this radio "100Yen radio"
Many radio amateur in Japan buy them and convert to various kinds of  electronic equipment. Or they take apart it and take out parts and use these parts to make other radios. I also used this 100 Yen radio to make some of my radios posted on this web site.
But regrettably, this 100 Yen radio had been disappeared last year (2004), may be discontinued.   Even today, We can buy some kinds of radios at 100Yen shop. But all of them use 1 chip radio IC, And so, they contain only a few useful parts for radio amateur.

                
           appearance                                                             inside
                               Left: D-cell for size comparison                            Many useful parts were contained                

                                                                 

Specification :

     Size             : 3.5"x2.2"x0.9"(except protrusion of knob) 

    Transistor     : S9011x 2 S9014 x 1,  and 1-diode

    Block diagram :  Converter    IF-AMP      2nd-Detector          AF-AMP  
                                  S9011       S9011         silicon diode             S9014
                                                           (switching type diode is used)

                               *Without power amplifier and loud speaker. earphone only.

    Schematic      : Almost standard circuit as above block diagram. 

    Batteries 
        requirement: AAA-cell x 2

    Earphone        : 32ohm dynamic type.