The Model 820 was the deluxe Lectron System product offered by Raytheon during their first product phase during the Fall of 1967 and sold for $31.95.
Deutsche Lectron, GmbH was the Lectron System manufacturer at this time and used the remaining Egger supplies for fulfillment requirements. This model, like the Model 800, was marketed as ‘Electronic Dominoes‘. The 820 model was later repackaged as the Series 3 with new packaging and cover graphics for Raytheon’s second product phase.
There were three shipped versions of the Model 820 which evolved as the Egger 8100 supplies were used up.
The first photo above shows an extremely rare early production run of the Raytheon 820 that I was very fortunate to acquire. It features the version 1 Egger 8100 styrofoam packaging and an Egger battery block with power switch, ornate silver foil strips over each row of the blocks on the right side (only existing on the version 1 of the Egger 8100), and the Egger badge.
The second photo immediately above shows a rare version of the 820 (used for the instruction manual’s example photo) which I was able to acquire in April of 2013. Prior to the eBay auction, it had been purchased at a yard sale in West Virginia in 2012. The first row of blocks on the right now have six block spaces instead of 4, the silver decorative strips were omitted, and the Egger badge was omitted. The six block space mold was used for Egger’s second version of the 8100. The bulb was also relocated from below the speaker to the fourth row of blocks, displacing the T connecting block.
Finally, the third version shown in the photo immediately above shows Raytheon (Deutsche Lectron was still the manufacturer) using the Braun white styrofoam block packaging during the production run, presumably after the Egger black packaging supplies were exhausted. Note that the Egger battery box has now been replaced with the Braun battery box. If you look in the upper left hand corner in the graphic above, you can see the embossed Egger 8100 model number.
The five experiments (23 – 27), which could only be done with the 820 kit, included a three transistor AM radio with loudspeaker.