I am sure some of you veteran hams have... but I think today I had my second Feld Hell (Hellschreiber) QSO. See videos below of actual signal and the decoding. I was using Ham Radio Deluxe for the QSO.
Here is some history regarding Feld Hell that I learned after the QSO. My interest was peaked and I thought it would make a good post for our website. The source of the information below was from these two websites.
"The traditional method of sending Hellschreiber by radio is to key a Morse-type (CW) transmitter ON for every black spot in a text character,and OFF for every white place. Different parts of each character are sent at different times. The technique is still in use by interested Amateurs, communicating world-wide. This mode is now called Feld-Hell (Field-Hell), since the pre-war format still used was originally used for field communications by the German Army. Feld-Hell offered good immunity to interference and provided a clandestine transmission capability, because nothing was transmitted until a key was pressed. Commercial variations of Feld-Hell could still be heard occasionally on HF up until the 1980s, transmitting Chinese and Korean characters."
"Feld-Hell characters are sent as a series of dots at 122.5 pixels/sec, using a CW transmitter, or these days, by sending tones to an SSB transmitter. Black dots are represented by a CW dot (key down), and white spaces by a space as long as one dot (key up). The timing requirements are quite precise, like FAX, but Rudolf Hell developed a simple but clever technique, which involves printing the text twice, which can negate the effects of phase and small timing errors, thus avoiding the need for true synchronism."