Links

Grundig
Grundig Radio Boy (en) (1980 Hits) (Lots of information about Grundig world receivers)
Grundig Satellit Warehouse (en) (2830 Hits) (Manuals and Schematics for Grundig Satellit radios)

Other receivers
Nostalgische Radios (de) (2043 Hits) (Very nice page about tube- and transistor radios with lots of images, descriptions, circuit diagrams and other documents.)
RadioMuseum.org (de) (en) (2276 Hits) (Very large site about vintage radios)
Technisat/Sangean ATS909 Kurzwellenempfänger (de) (2009 Hits) (Information about the ATS909)

Tests and articles of receivers
Martin's Radio Pages (de) (1954 Hits) (Lots of top quality tests about shortwave receivers.)
Modern Shortwave Receiver Survey (en) (2101 Hits) (One of the most extensive receivers lists online)
Radio Netherlands Receiver Survey (en) (1483 Hits) (Tests of all current and some discontinued world receivers)
Welchen Empfänger brauchen Sie? (en) (1579 Hits) (Tips about sw receivers from the team of the HJCB Quite, the Voice of the Andes)