Links

Grundig
Grundig Radio Boy (en) (1959 Hits) (Lots of information about Grundig world receivers)
Grundig Satellit Warehouse (en) (2815 Hits) (Manuals and Schematics for Grundig Satellit radios)

Other receivers
Nostalgische Radios (de) (2019 Hits) (Very nice page about tube- and transistor radios with lots of images, descriptions, circuit diagrams and other documents.)
RadioMuseum.org (de) (en) (2104 Hits) (Very large site about vintage radios)
Technisat/Sangean ATS909 Kurzwellenempfänger (de) (1995 Hits) (Information about the ATS909)

Tests and articles of receivers
Martin's Radio Pages (de) (1929 Hits) (Lots of top quality tests about shortwave receivers.)
Modern Shortwave Receiver Survey (en) (2078 Hits) (One of the most extensive receivers lists online)
Radio Netherlands Receiver Survey (en) (1469 Hits) (Tests of all current and some discontinued world receivers)
Welchen Empfänger brauchen Sie? (en) (1551 Hits) (Tips about sw receivers from the team of the HJCB Quite, the Voice of the Andes)