Crystal receivers

This was one area of radio that fascinated me, although I have not explored it recently. At one time, my ambition was to build a crystal set that covered VLF to over 1 GHz with maximum sensitivity. 

Remember, crystal sets are passive receivers generating all their power from the TX. Some designs use the rectified signals from many stations to bias the detector on or to power a small amplifier.

These days there are fewer English language broadcast stations on short wave.

In my time I have received stations from all over the world, not via relays that can be much nearer. I have heard amateur and commercial stations too.

Most crystal sets can copy about 1mV signals, although I expect optimised systems can receive far weaker signals.

There is a page on my website about these.

See https://sites.google.com/view/g3xbm4/home/hf-mf-and-lf/crystal-set-dxing