Sidebands
 

Szczepan Bialek wrote:

Uzytkownik "Jeff" napisal w wiadomosci
...

I am trying to find if that SSB from 1915 were the distance dependent.
S*

Distance from where? You are not making sense.

From the station.
S*

The modulation used has nothing directly to do with the distance a signal
is usefull. That is determined, at a given power and state of the the
ionosphere, mostly by signal to noise ratio which is influenced by the
bandwidth of the modulation method but not by the modulation method itself.

Electomagnetic propagate works the same today as it did in 1915 or even
30,000 BC if anyone had been around with a radio.

You are a babbling idiot.


--
Jim Pennino

Remove .spam.sux to reply.

Sidebands
 

On Dec 22, 12:59*pm, wrote:
What was in 1915?
S*

The battleship HMS Formidable is sunk off Lyme Regis, Dorset, England, by
a German U-Boat. --
Jim Pennino

Gallipoli landings.

Sidebands
 

Uzytkownik "Richard Fry" napisal w wiadomosci
...
I am trying to find if that SSB from 1915 were the distance dependent.
S*

Distance from where? You are not making sense.

From the station.
S*
________________

Radio waves behaved the same in 1915 as they do now.

The distance to a given field intensity, for the same conditions, is the
same now as it was then.

Look at the damped waves: http://en.wikipedia.org/wiki/Damped_wave

The damped waves pulses are simillar to AM (amplitude of oscillation
decreases/increases with time).

The decreasing/increasing may be sharp or gently.

The old damped waves " transmissions have a wide bandwidth".

Was the bandwith the distance dependent?
S*

Sidebands
 

"Jeff" wrote ...

Nope, you haven't the slightest bit of understanding of what the term
"passband" means so your question is nonsense.

"Radio receivers generally include a tunable band-pass filter with a
passband that is wide enough to accommodate the bandwidth of the radio
signal transmitted by a single station."

That statement is at best misleading, and in some cases incorrect.

In most receivers any *tunable* filter is MUCH MUCH wider than the
bandwidth required to accommodate the bandwidth of the signal transmitted.

The selectivity being produced by one or more *fixed* frequency filters
which are just wide enough to accommodate the bandwidth of the wanted
signal.


For me a radio is a box with the knob to rotate.
Now at FM no brakes between stations. At AM are.

What was in 1915?
S*


In 1915 there were no broadcast stations to speak of so your dial would
be just one large "brake" (sic).

"Well, it's like this. The story starts in 1915, when mankind discovered
sidebands. Now possessing this superior understanding of the AM signal,
radio scientists began to understand the implications of their discovery.
Soon afterwards, our old friends at Bell Labs, who have discovered
practically everything, developed a method for removing one of the sidebands
of an AM signal but retaining all the essential modulation components. As an
expert of that day supposedly said, "both sidebands are saying the same
thing" (Goodman, 1948). " From:
http://www.hamradiomarket.com/articles/SSBHistory.htm

If in 1915 were no broadcast stations to speak tell us what was with the
first station to speak and when it start transmitting.
S*

Sidebands
 

For me a radio is a box with the knob to rotate.
Now at FM no brakes between stations. At AM are.

What was in 1915?
S*


In 1915 there were no broadcast stations to speak of so your dial
would be just one large "brake" (sic).

"Well, it's like this. The story starts in 1915, when mankind discovered
sidebands. Now possessing this superior understanding of the AM signal,
radio scientists began to understand the implications of their discovery.
Soon afterwards, our old friends at Bell Labs, who have discovered
practically everything, developed a method for removing one of the
sidebands
of an AM signal but retaining all the essential modulation components.
As an
expert of that day supposedly said, "both sidebands are saying the same
thing" (Goodman, 1948). " From:
http://www.hamradiomarket.com/articles/SSBHistory.htm

If in 1915 were no broadcast stations to speak tell us what was with the
first station to speak and when it start transmitting.
S*


The first AM Broadcast station (as opposed to amateur or military ) was
in about 1919.

Jeff

Sidebands
 

Look at the damped waves: http://en.wikipedia.org/wiki/Damped_wave

The damped waves pulses are simillar to AM (amplitude of oscillation
decreases/increases with time).

The decreasing/increasing may be sharp or gently.

The old damped waves " transmissions have a wide bandwidth".

Was the bandwith the distance dependent?
S*

Damped waves bear little or no similarity to AM, they are essentially
pulses with a very different spectral content.

Being pulses the spectral content is wide, tending to infinite, and yes
I suppose that the spectrum received by a distant station will vary
depending on distance; the lower level spectral lines that are spaced a
long way from the fundamental will be lost below the noise as you get
further away or the signal gets weaker due to propagation changes. The
more side-bands that you loose the slower will be the rise and fall time
of the received pulse.

AM is very different the spectrum is much more contained and only 1
side-band is required to replicate the waned signal.

Jeff

Sidebands
 

Szczepan Bialek wrote:

If in 1915 were no broadcast stations to speak tell us what was with the
first station to speak and when it start transmitting.
S*

There were no broadcasting stations of any kind in 1915.

The first station that could even remotely be called a broadcasting station
was in 1916 and it broadcasted weather reports in morse code.

The first experimental AM broadcast stations started in 1919 and regular AM
broadcasting started in 1920 when all the spark gap morse transmitters
were shut down.


--
Jim Pennino

Remove .spam.sux to reply.

Sidebands
 

Szczepan Bialek wrote:

Look at the damped waves: http://en.wikipedia.org/wiki/Damped_wave

The damped waves pulses are simillar to AM (amplitude of oscillation
decreases/increases with time).

Only to someone who hasn't a clue what they are talking about.

The decreasing/increasing may be sharp or gently.

The old damped waves " transmissions have a wide bandwidth".

Was the bandwith the distance dependent?
S*

Word salad gibberish.


--
Jim Pennino

Remove .spam.sux to reply.

Sidebands
 

On Dec 23, 1:56*am, Jeff wrote:
For me a radio is a box with the knob to rotate.
Now at FM no brakes between stations. At AM are.

What was in 1915?
S*

In 1915 there were no broadcast stations to speak of so your dial
would be just one large "brake" (sic).

"Well, it's like this. The story starts in 1915, when mankind discovered
sidebands. Now possessing this superior understanding of the AM signal,
radio scientists began to understand the implications of their discovery.
Soon afterwards, our old friends at Bell Labs, who have discovered
practically everything, developed a method for removing one of the
sidebands
of an AM signal but retaining all the essential modulation components.
As an
expert of that day supposedly said, "both sidebands are saying the same
thing" (Goodman, 1948). " From:
http://www.hamradiomarket.com/articles/SSBHistory.htm

If in 1915 were no broadcast stations to speak tell us what was with the
first station to speak and when it start transmitting.
S*

The first AM Broadcast station (as opposed to amateur or military ) was
in about 1919.

Jeff

KCBS, San Francisco, claims to be the direct lineal descendant of
Charles Herrold's broadcasting, which dates from 1910. However,
Herrold's early work involved broadcasting to amateurs, by his own
admission. http://www.charlesherrold.org/KCBS.html, et al.

KCBS and KDKA, Pittsburgh, have been trading claims and counterclaims
for decades. KDKA went on the air in November, 1920 and supporters of
their claim of "First!" say KCBS doesn't date from the Herrold days,
but rather from 1921, when they got their earliest commercial license,
as KQW. I don't claim to be able to settle it here. Oy!

"Sal"

Sidebands
 

If in 1915 were no broadcast stations to speak tell us what was with the
first station to speak and when it start transmitting.
S*

The first AM Broadcast station (as opposed to amateur or military ) was
in about 1919.

Jeff

KCBS, San Francisco, claims to be the direct lineal descendant of
Charles Herrold's broadcasting, which dates from 1910. However,
Herrold's early work involved broadcasting to amateurs, by his own
admission. http://www.charlesherrold.org/KCBS.html, et al.

KCBS and KDKA, Pittsburgh, have been trading claims and counterclaims
for decades. KDKA went on the air in November, 1920 and supporters of
their claim of "First!" say KCBS doesn't date from the Herrold days,
but rather from 1921, when they got their earliest commercial license,
as KQW. I don't claim to be able to settle it here. Oy!

"Sal"

A year earlier PCGG in Holland started broadcasting on November 6, 1919
and is thought to be the first 'real' broadcast station.

On 15th June 1920 Marconi made their first broadcast to the public from
their works in Chelmsford, but it took until 1921 before there were
regular programmes.

Jeff