From: ken scharf on Sat, Feb 17 2007 9:17 am
wrote:
On Feb 16, 2:00?am, (Geoffrey S. Mendelson) wrote:
ken scharf wrote:
Wonder if A2 operation with USB tone modulated code would be legal on
these bands?
Bear in mind Morse code was designed to be used in a mechanical punched
tape sending device. It was never meant to be sent or received by hand.
It was just by accident that an operator found out he could copy the message
directly into his head by listening to the sound of the pen.
Ahem...small disagreement there. Morse's original "code" was
all numeric and the receiver was an inked trace on paper tape.
Vail, not Morse, replaced the tape sender with a hand key, and dropped
the pen from the receiver.
Alfred Vail's family was Morse's financial benefactor. The Vail
locomotive works tried to get the ink pen receiver to work
reliably and couldn't. At the same time Morse was having
trouble organizing his all-number "code" to cover enough
English language common phrases. According to the Vail
family website information, Alfred Vail suggested to Morse that
the whole English alphabet should be part of the "code."
Alfred suggested copying the frequency of letters of a printer's
type case as a way to make the most-used characters take
the least time to send.
Eventually, long after the hand key and acoustic "sounder"
were in common use, the ink-printed-on-paper-tape (or drum)
came back for very long circuits such as under-ocean lines.
Also the "Morse" code invented by the man of the same name is NOT the
same cypher (it's NOT really a code!) that we hams use over the air.
Irrelevant in the historical context of 1844 (163 years ago)
and the beginning of the Morse-Vail Telegraph Company...or
the period of 52 years of landline telegraphy before the
first demonstration of radio as a communications medium in
1896 (in Italy and Russia). In that period between 1844
and the "turn of the Century" (1899-1900) landline telegraphy
became a mature financial success and was duplicated (in
"technology") around the world, partly on the Morse-Vail
innovation-invention of the "relay." That "relay" enabled
a single telegraph circuit to extend over three times its
un-relayed length and reduced the capital investment of the
telegraph companies.
Underwater telegraph lines proved a financial success despite
the high cost of such telegrams. But, technically, such under-
water lines suffered high line losses, necessitating the
return to galvanometer-like ink pens at the receiving end...
the original intent of Morse's telegraph system.
The word "code" is a very, very general descriptor of any
system that uses a REPRESENTATION of a language or
communication data. Other examples are the so-called Baudot
code (5-level) or ASCII, the American Standard Code for
Information Interchange (8-level) in teleprinting systems.
The word "cypher" also has many meanings (including old
references to mathematical operations) but, in the modern
sense becomes more allied with cryptographic methods of
obscuring the meaning of communications. See 'crypto'
references to differences of "cyphertext" and "cleartext."
In the half-century prior to 1900 ("turn of the century"
in the phrase of older times), a great number of different
"dialects" of the "morse code" were generated, mostly to
fit the languages of its users. By that turn of the century
time land and sea telegraph systems had multiplied and
were confounded by all the various languages and dialects
of the telegraphic code. That was resolved somewhat by an
international standards group called by the French acronym
CCITT. The CCITT resolved a great number of communications
means, protocols, tariffs, and methodologies to enable a
quicker 'throughput' of communications between countries.
What eventually came out of the CCITT telegraph standards
work as the "international telegraph code" was based on
the English alphabet, numerical notation, and punctuation.
That wasn't because English was a "better" language but
simply that it was the MOST USED language for international
telegraphy AT THE TIME. Note that the teleprinter codes
were also standardized on the 5-level system. Teleprinter
systems would eventually dominate and succeed telegraphy
systems for international communications.
Geoffrey and I were communicating on the OLD technology of
(largely) manual telegraphy systems. It is not demeaning
to say that such pre-1900 technology was PRIMITIVE. It
was. There were no vacuum tubes to amplify anything and
certainly no "radio" (until 1896 public demonstrations).
Exactly what the early manual telegraphers did is relatively
unimportant to the modern-day radio-electronics amateur
radio world. Whatever they did was a relative success over
a half-century of use and growth. But, that success was
based on PRIMITIVE electrical technology.
What seems to be overlooked in early telegraphic technology
is the remarkable innovation of the RELAY. A simple electro-
magnet driving a contact. Make the electromagnet sensitive
enough to work with a 30-mile stretch of wires...wires NOT
made to uniform standards which had not yet been developed.
This simple relay could form an UNATTENDED telegraph station
along a route, having its own battery for powering the out-
going line to the next station, keyed by the relay contacts.
Up to three unattended relays could be used on one
circuit...reaching up to 100 miles in length before the
circuit characteristics began causing errors in transmission.
No real time of transmission ensued, something that had to
be considered with attended stations and the operator copying
down one telegram, then resending it manually to the next
station. Think of the telegraphic relay as a predecessor
to the modern-day radio REPEATER. Same unattended method
of relaying a communication, almost in real time.
WE
use what's actually called the "international radio telegraph" cypher
(code). True Morse has characters based on dots, dashes, long dashes,
and variable spaces!
That code is fully described as to dots, dashes, and spacing
in the referenced document given in the "Definitions" section
of Part 97, Title 47 C.F.R., as it applies to USA radio
amateurs. I have a copy of that, purchased from the ITU.
Interestingly, that same document does not define the
equivalent rate-of-transmission...although the USA amateur
radio regulations imply that it does.
Also as sent over the land line the operator had
to listen for the gap between clicks NOT the sound of the clicks! Try
that folks!
Irrelevant as to what any telegraph operator did prior to
1900...except for historical notation. None of the participants
of any newsgroups were alive then and therefore none can be
"witnesses" to corroborate methods of early telegraph reception.
Perhaps the first appearance of the "BFO" in radio reception
was an experiment by early radio innovator Reginald Fessenden.
Fessenden ran a low-power Spark transmitter next to his early
receiving detector and noted that detector sensitivity was
increased (his major area of experimental research at the
time. He did not coin any term such as "beat frequency
oscillator;" that came later after Armstrong invented the
"super-heterodyne" receiver (name in reference to Fessenden's
experiment notation) with a fixed-tuned IF.
To simulate the "listening between clicks" on a radio, simply
turn the BFO OFF with a strong "CW" signal coming in. That
isn't a good duplication because there is a slight hiss of the
distant carrier when it is on, perhaps a tiny bit of hum. If
the distant signal is weak, the spaces between carrier-on
dots and dashes would have some random noise. Either way, it
is not a good way to "copy CW" without that BFO.
---
The start of this thread was a question on whether or not FCC
06-178 that goes into effect on 23 Feb 07 will "eliminate the
CW bands." It will not as is noted in FCC 06-178. Let's not
deviate into esoteric realms of potential flame-war ignition
about "true morse code." USA amateur radio regulations are
rather specific on the relative lengths and spacing of
International Morse Code as defined by the ITU.
As to "homebrew" subjects, I submit that the Morse-Vail
telegraph patent was an example of that in their "relay."
Electro-magnets were known in 1844. Wire characteristics
and early DC batteries were known. The telegraph patent
connected them all in that "relay," something that no one
else seems to have done at the time. Now, I consider that
to be in the best spirit of "homebrewing." Innovation,
doing what had not been done before. Others mileage may
vary...