During a spell that lasted for just over a couple of hours, on Saturday January 29 2016, I was able to complete 7 QRP contacts in Hell. Then, all of a sudden, it all broke loose…
Hell, of course, is Hellschreiber, the historic German digital mode invented by Rudolph Hell for radio communications during WWII, and I was participating in on of the sprints of the Feld Hell Club (https://sites.google.com/site/feldhellclub/Home). What makes the Hell mode unique and interesting in radio amateur communications is that the man-machine interaction is entirely visual, as the audio send from the radio to the receiving computer is only used to make each pixel in each letter appear on the screen. The interpretation of those matrix graphics as text entirely depends on visual letter recognition by the human eye and the user ability to read text. If the printed characters were anything but those in the regular alphabet, becoming proficient in Hell might take as long as learning CW. But since most of us have already gone through that training during early childhood, success for most users is almost immediate.
I was using the ICOM 703 rig with a Signalink USB interface and an old ThinkPad IBM T60 laptop still running Windows XP. I’ve kept that computer in the shack because it can take a PMC card providing for two serial ports, which I use to interface the computer with the radio. In that computer I have two pieces of software that can receive and transmit in Hell mode: “Fldigi” by W1HKJ (http://sourceforge.net/projects/fldigi/files/) and “Hellschreiber” by IZ8BLY (http://antoninoporcino.xoom.it/Hell/index.htm). I’ve used both and for several reasons I prefer Fldigi. For one, it seems to be kinder on the relays of the ICOM 703. A major difference from other digital modes is that since the computer reception is in graphic mode, the callsign, name, QTH, etc. of the sending station are not available at a mouse click, and can only be logged manually. In exchange Hell offers direct visualization of subtle changes in HF propagation, QSB and QRN. QSB can actually be seen causing changes from one character to the next. Also I find the unmistakeably rasping sound of Hell to be less unnerving than the sound of RTTY, PSK and many other digital modes.
I was getting used to the sound of Hell as the relays of the ICOM 703 were clicking happily sending Hell RF to the antenna, when all of a sudden the ICOM locked itself in transmit mode. “What the…!” was my initial reaction – without realizing at first the obvious and painful pun. At every subsequent try the ICOM kept locking after initiating transmission. I checked all the settings in the radio, the computer and the software, as well as all connections between them. Everything seemed ok. However this put an abrupt and definitive end to my participation in this sprint of Hell.
Later in the night I decided to try a few SSB contacts in the lower bands and remembered that in those bands the T1 auto-tuner reached a better SWR value with a 9:1 unun in place of the regular 4:1. As I accessed the tuner to switch ununs, I noticed that the ground-wire for the T1 had detached from the grounding copper pipe. After I reconnected it, Hell signals could be transmitted again without hiccup.
It does not come to a complete surprise that Hell might require a connection to ground at all times, but how the devil did the ground-wire get disconnected in the first place?