A Digital HF Mode By N4UFP Marc Tarplee Tweaks by K7AGE Randy Hall - - PowerPoint PPT Presentation

A Digital HF Mode By N4UFP Marc Tarplee Tweaks by K7AGE

Randy Hall K7AGE Pacificon 2012 k7age@k7age.com

I was first licensed in 1968 I’ve been around video since high school

Built a TV camera as high school electronics project Worked on remote TV broadcast as cameraman and engineer Worked at college TV studios

Work for broadcast equipment manufacturers

Belden/Miranda/NVISION and Grass Valley Group

First Youtube video in August 2006, now over 6 years

76 videos Over 2.2 million views 6400+ subscribers

My WHAT THE HELL video has over 83,000 views

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“Typenbildfernschreiber”

that is: a character‐image tele printer

(writer)

named after its inventor, Rudolf Hell

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Wikipedia provides further background for the use of the term “HELL” "Hellschreiber" translates into English as "Light Writer," "Bright Writer," or "Clear Writer," and is a pun on the name of its inventor (Rudolf Hell) Hell (the adjective) is German for "light," the adverb is "bright."

Developed By Dr. Rudolf Hell of Germany

• Dr. Rudolf Hell (1901‐2002) was one of the most important German inventors of

all time. E.g., with Prof. Dieckmann he invented the Photoelectric Image Scanning Tube (TV camera tube, patented in 1925); Electronically controlled "Klischograph" half‐tone photo‐engraver in 1951 First practical fax machine in 1956, Color scanner in 1963 Computerized CRT type‐setter in 1965, and many technical processes.

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What is Hellschreiber?

A simple fax mode No‐decoding, you do the the decoding Developed back in the late 20s Uses by German military along with Enigma during WWII Used into the 80s by news wire services Intelligible communications over poor circuits Feld Hell, for Field Hell

Today, another one of the many digital modes

Free software Uses typical PSK‐31 sound card interface

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Developed as an alternative to the teletype machines

Less moving parts Less sensitive to synchronizing Simpler radio interface Intelligible communications over poor circuits

We will see examples as we go along

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Can you count the number of parts? Complex to maintain Let’s watch it run…..

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A lot less parts

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Does not send data Does not send text, as data Does not synchronize sender and printer It does send pixels, one at a time

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the pixel bit-sequence is wrapped into a ring The character-drum is the character-set “font” memory

• ne ring for each character of the Hell-font

the rings are combined into a cylinder - the “character drum”

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Motor pulls the paper tape Motor turns the cork screw print head Audio decoded to trigger a solenoid at each pixel The solenoid hits from below the paper opposite the print head for each pixel Printed!

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45.45 Bd 60 WPM 270 Hz no no 100% no no RTTY 367.5 Hz 6‐39% duty‐cycle telegraphy signaling rate 122.5 Bd 35 WPM necessary bandwidth error correction or data redundancy no large (60+ pix/char) Useable with CW Xmtr? (On‐Off‐Keying) yes Requires very stable TX/RX freq? no Feld‐Hell 31.5 Bd 50 WPM 62.5 Hz no no 80‐100% no yes PSK‐31

*

Very comfortable typing speed. 19

Feld‐Hell (raised‐cosine) PSK‐31

PSK31: normal modulation

RTTY (45.45 Bd, 170 Hz shift)

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Able to read weak signals, they just get faint

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There is no synchronization between sender and printer Phase differences causes the text to print at a slant Two lines, means YOU can always read the text

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Today, like some many other modes

Implemented in the computer with

Sound card Software

Easy to get on the air. Look at the software

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Windows Simple 2004 Free http://anoninoporcino.xoom.it

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www.w1hkj.com

Windows Mac Linux All in one program Switch easliy between PSK, Hell, and other modes Free

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Windows Do All Program You may be using this now Switch easily between PSK, Hell, and other modes Free to $$s www.hrdsoftwarellc.com

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IZ6HPJ, Bronzi Luca

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HF radio

USB mode

Computer with software Sound card interfaced to radio

If you are on PSK‐31 you are set to go

Find the activity

A challenge

But ……..

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Feld Hell Club

Monthly Sprint Contests

Simple fun time Nov 17 Turkey Shoot 16:00‐18:00 UTC Lots of stations, short time for the contest Get on and have fun, easy Free to join and get your Feld Hell number Google Feld Hell Club for website

Frequencies

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160 METERS 1.804 80 METERS 3.574 to 3.584 40 METERS 7.077 to 7.084 30 METERS 10.137 10.144 (Region I)

20 METERS 14.063 (PREFERRED), 14.073 (Note 1)

17 METERS 18.104 15 METERS 21.074 12 METERS 24.924 10 METERS 28.074 6 METERS 50.286 Note 1: For 20 meter ops, the FHC calling frequency is 14.063 and UP to 14.069. PSK31

• ps are on 14.070 and the QRP club uses 14.060 as their calling frequency. We do not

wish to cause interference to each other. A reminder, QRP is a power reference, not a

• mode. If using 14.073, be sure to avoid interference with the JT65 area at 14.076. Even

though some may encroach on our segment, we need to be be the good guys!

Hellschreiber is a Fuzzy Mode, classified as J2B. As such Hellschreiber may be transmitted on CW or phone amateur radio frequencies. The list above is a starting point for your activities. The club expects that operators will operate with the high ideals of Ham Radio in mind, and be vigilant against QRMing our fellow hams.

Below the PSK waterfall!

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Easy Try a new mode Learn something new Interesting to watch text printing If you are on PSK‐31

Get the free software and try it out

Join in a simple short contest

Lots of activity

FUN

With a 80 year old mode brought up to date

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k7age@k7age.com Thanks to N4SPP Frank Dörenberg

Very in depth Hellschreiber website www.hellschreiber.com Lots of data, graphics, animation, and text

Your thoughts and questions?

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