Principle of Auto Azimuth Correction system as patented by Philips in 1979 (patent NL7805803), and later produced as Marantz SD-930 and Nakamichi Dragon.
<a href="//commons.wikimedia.org/w/index.php?title=User:Retired_electrician&amp;action=edit&amp;redlink=1" class="new" title="User:Retired electrician (page does not exist)">Retired electrician</a> based on drawings and explanation in US patent 4317144 <a rel="nofollow" class="external autonumber" href="https://patents.google.com/patent/US4317144A/en">[1]</a> and <i>Craig Stark. Nakamichi Dragon cassete deck // Stereo Review April 1983 p. 38</i>
2019-04-24
<span class="int-own-work" lang="en">Own work</span>