A verified collection should have a master index file (usually a separate PDF or a spreadsheet) listing every issue number, year, and page count. Open a random issue – e.g., May 1985. Does the cover match the content inside?
Low-resolution scans (72 DPI) are useless for reading component values or tracing PCB tracks. Verified collections are typically scanned at 300 DPI or higher, black-and-white or grayscale with proper contrast adjustment to make schematics legible. revista elektor coleccion completa pdf verified
If you have a set of PDFs and want to check authenticity: A verified collection should have a master index
If your goal is to study electronics projects from Elektor, many classic circuits are also republished in Elektor’s “Best of” books (e.g., 301 Circuits), which you can buy cheaply secondhand. Legal alternative: Buy a used official Elektor DVD/USB