Sadly there are lots and lots of online sellers selling fake 1n34a diodes. Most likely they are Schottky diodes that will give lower performance and distorts the analog radio signal into something square-ish.
Let's do an easy test that does NOT require a frequency generator, oscilloscope or other high dollar test equipment. Only a decent VOA meter and a 1.5 volt battery is required.
This is one of the videos I referenced. The guy shows the difference in waves of the 1n34a and schottky. [ Ссылка ]
UPDATE: I bought some D9K diodes that are good substitutes for the 1N34A on ebay from "Stavr-Tube&Tones up grade".
Crystal Radio--A Good 1N34A Diode Substitute [ Ссылка ]
Video: Best/Easiest DIY Crystal Radio - No Batteries, No External Power (4K)
[ Ссылка ]
