Gakken EX-System

The Gakken EX-System, also known as EX-Series was first launched in 1976 and consisted of denshi blocks which fitted into a portable radio style green coloured case. It had a transparent flip cover, which secured and protected the denshi blocks. This electronic experiment set was the creation of Denshi Block Mfg Company, and produced in collaboration with the Gakken Company of Japan. In approximately 1986, these kits stopped appearing under the Gakken name and continued under the Skilcraft name, which was a division of Monogram Models Inc. Some also appeared with the Humbrol label. Therefore, from being "Denshi Blocks", it became "Skilcraft Electronic Blocks". An advantage of this kit is that it has an AM radio coil and tuning capacitor; hence it is ideal for anyone starting out with an interest in making crystal radios. This kit can potentially save you time and money looking for crystal radio parts; hence in that sense it is very useful.

Although Gakken made many versions, and the last one being EX-FM, which is a kit with an FM tuner multiplex, the Skilcraft EX-System consisted only of EX-60, EX-100, and EX-150. If you had the EX-60, then the addition of EX-C parts upgraded your system to the EX-100. Alternatively, if you had the EX-100, then the addition of EX-G parts upgraded your system to the EX-150.

EX-60 had 30 denshi blocks and allowed for 60 circuits, whilst EX-100 had 38 denshi blocks and allowed 100 circuits. The EX-60 and EX-100 were basic budget-end models and did not come with a meter, CdS Cell, or transparent flip cover. They also did not come with a microphone, and instead had a drawing of it on card. In the manual, they provide an Illinois based address for purchasing these extras. The EX-150 was the complete unit and had 46 denshi blocks that allowed for 150 circuits.

IC AMP Module

All three in the series had the IC AMP module within the main case. The amplifier module consisted of LM386N Low Voltage Audio Power Amplifier, and the necessary circuitry including a volume control. The module was detachable from the main case, and you can see this in the following sections of this multi-page article.

Tuning Control

Power Switch

For Sale / eBay

These units are highly desirable with collectors and whether it is an EX-60, EX-100, or EX-150, I would grab it as they are essentially the same with a different number of denshi blocks. If you are looking for any for sale on eBay, then you should also search under the names Skilcraft, and Humbrol, as well as Gakken.

Their cost is approximately the same providing they are complete with the instruction manual and in good condition. If you have one for sale, and it is in mint condition, then on a good day, it could make a tidy sum.

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