LF: Feldhell on the 136kHz band coming weekend

["Dick Rollema" <d.w.rollema@freeler.nl>]

Dear OM,

It is my intention to make a transmission in Feldhell on Saturday 22 June
at 1300 UTC and Sunday 23 June at 0900 UTC. I will be using an original
German World War II Hellschreiber
("Feldfernschreiber") made in 1944.

The transmission will start with some minutes of the "pause
signal" that the machine can send. It will be followed by some lines
of text. After the transmission I will listen for replies in Feldhell or
in CW. Reports via the Reflector are also welcome of course.

My question is what will be an appropriate frequency
for the test? 137kHz?

Sending by Feldfernschreiber is not easy and requires
some training. The machine dictates the transmission speed of 2.5 char/s
and the operator has to achieve that by typing at a constant and precise
rhythm.
When you want to send a character a finger is lightly put on the key for
that character. But the key cannot be depressed because the machine
prevents that. When the proper moment for sending arrives the key is
released and it moves down under pressure of the finger. It is then
important to immediately put a finger on the key for the next character.
When you wait too long the proper moment has been lost and you have to
wait for the next turn. Because the paper tape moves on continuously a
space appears instead of the character you wanted. 
One would think there is no need for a space key because a space is
produced automatically as long as no keys are depressed. Nevertheless a
space key is present on the keyboard!
I assume that is done so that the operator can type at a constant rate
without any interruption. In Germany this type of typing is called
Taktgeben.
Another difficulty in operating the Feldfernschreiber is that the keys
for the Y and Z have changed places (QWERTZ instead of QWERTY). 
I have been using the machine in numerous Hell QSO's on 40 and 80 since
1977, but I still produce typos and unwanted spaces.
The keyboard has keys for letters A ...Z, numerals 0...9 and for /, ?, +
and -. In addition keys for the pause signal and for sending morse
code.

For more about the Feldfernschreiber you can visit the website of
Murray Greenman, ZL1BPU:
http://www.qsl.net/zl1bpu/;
next select "Feldhell".
You also find software there that can convert a PC with soundcard into a
Feldfernschreiber.

I now use a transmitter that was made by Harry Grimbergen, PA0LQ. Harry
used the TX himself on LF until the manager of the apartment building in
which Harry lives on the top (12th) floor forbade him stringing an
aerial.
Harry sends greetings to all who have worked him in the past on the
136kHz band.

The transmitter is VFO controlled and has in the final amplifier four
tetrodes PL519 in parallel. At a DC input of 0.95A x 520V = 494W they
produce about 320W output. 

I am looking forward to some Hell QSO's on LF.

73, Dick, PA0SE
JO22GD