On 13 Mar 2005 15:18:03 -0800, wrote:



also, when people refer to ASK and FSK, is ASK basically an audio
output that's been sent over FM? and FSK is more like CW, only to a
receiver that can monitor both mark and space (0 and 1) frequencies?

thanks again!
jason

always thought amplitude-shift-keying was mainly used for morse
---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm

"J M Noeding" wrote in message
...
On 13 Mar 2005 15:18:03 -0800, wrote:



also, when people refer to ASK and FSK, is ASK basically an audio
output that's been sent over FM? and FSK is more like CW, only to a
receiver that can monitor both mark and space (0 and 1) frequencies?

thanks again!
jason

always thought amplitude-shift-keying was mainly used for morse
---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm

I believe he meant AFSK (audio frequency shift keying) vs FSK (frequency
shift keying).

Dee Flint wrote:
"J M Noeding" wrote in message
...
On 13 Mar 2005 15:18:03 -0800, wrote:



also, when people refer to ASK and FSK, is ASK basically an audio
output that's been sent over FM? and FSK is more like CW, only to a
receiver that can monitor both mark and space (0 and 1)
frequencies?

thanks again!
jason

always thought amplitude-shift-keying was mainly used for morse
---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm

I believe he meant AFSK (audio frequency shift keying) vs FSK
(frequency
shift keying).

yes, that is what i meant. i didn't even know amplitude shift keying
existed.

am i correct about afsk being audio tones transmitted over FM, while
fsk is just alternating between two non-modulating frequencies?

jason

In article .com,
wrote:

yes, that is what i meant. i didn't even know amplitude shift keying
existed.

am i correct about afsk being audio tones transmitted over FM, while
fsk is just alternating between two non-modulating frequencies?

That's pretty close, but not exactly on target.

AFSK can be used on top of either AM or FM. In amateur systems it's
most commonly used with FM.

FSK shifts the carrier frequency... a process which counts as a
modulation. The amount of frequency shift (in Hz) and the rate at
which you shift it (also in Hz) vary a lot from one usage to another.
There are both narrow-band and wide-band FSK modulations in use.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Dave Platt wrote:
In article .com,
wrote:

yes, that is what i meant. i didn't even know amplitude shift keying
existed.

am i correct about afsk being audio tones transmitted over FM, while
fsk is just alternating between two non-modulating frequencies?

That's pretty close, but not exactly on target.

AFSK can be used on top of either AM or FM. In amateur systems it's
most commonly used with FM.

FSK shifts the carrier frequency... a process which counts as a
modulation. The amount of frequency shift (in Hz) and the rate at
which you shift it (also in Hz) vary a lot from one usage to another.
There are both narrow-band and wide-band FSK modulations in use.

thanks! also, i was just reading about mixers... and getting confused.
i've run some matlab programs to figure out how you can take something
at frequency x and frequency y, and end up with an output of frequency
(x-y). one transmitter's mixer i saw took a 160mhz and 14mhz input to
get a 146mhz output. adding or multiplying them together certainly does
not yeild 146mhz. so how does that work?

thanks for the help!
jason

I believe he meant AFSK (audio frequency shift keying) vs FSK
(frequency
shift keying).

yes, that is what i meant. i didn't even know amplitude shift keying
existed.

am i correct about afsk being audio tones transmitted over FM, while
fsk is just alternating between two non-modulating frequencies?

jason


You are partly correct. If audio tones are fed into the microphone input
(audio stages) of an AM or FM transmitter you are generating AFSK. If an
audio tone is fed into a SSB transmitter it will generate a single output
frequency. If the tone is switched off and on , it will be received as a CW
transmitter being keyed off and on. Some newer transceivers generate CW
this way. If the tone is shifted in frequency , the output will be a
carrier shifted the same ammount. This is received the same as a FSK
transmitter. You can get the same effect if you have a crystal controled
transmiter and switch a capacitor across the crystal to change the
frequency.
There is almost no way to tell the differance between the two. If 100% pure
tones are used and everything else it 100% correct then there is no
differance in the transmitted signals. As always nothing is 100% and you
can tell the differance with very close and strong signals. This is still
close enough it does not matter.

"Founding Fathers" wrote in message
...

wrote in message ...
just to make sure i have it straight, if i were to transmit a sine wave
at 146mhz, anyone listening in on 146 mhz wouldn't hear anything
....[snip]....

CW is NOT dead on two meters; anyone listening in CW mode would hear
you!
--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and
cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785)
539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle,
Pistol)


Amen brother! Outstanding signature line. Only thing I can add is the
"Cartridge Box" protects all the other boxes and is the one that is on
the
top of the big government blue state looney liberals' hit list.
Democrats
SUCK! I fear the federal government but love my country and its
Constitution. John Kerry is a liar.

The Repooblicans did a real spin on Kerry. And you bought it. They were
going to attack the AARP as a *gay* association! Good lord, if it weren't
for the many Bible-thumping modest double-digit IQ types, the Republicans
couldn't get off the ground. Fortunately, for them, there are a *lot* of
Bible-thumping double-digit IQ types and with the endless funding from big
business - well, you will discover what happens.

Since jobs moved to China, I'm thinking of buying from the company that
bought the IBM personal computer division. The profits might as well go
there as well.

Why does a guy with whom I work have a 10% service connected disability and
cannot get VA care (despite an honorable discharge)? They keep cutting VA
funding.
He has no health insurance. He is working repairing digital cameras, so he
is not totally brain-dead. Unfortunately, only contract work is available
these days and wages are not only stagnating, they are going down.

Canada was smart. They knew the U.S. wanted them in on the missile defense
so Canada could pay - and Canadians are *not* stupid, unlike many Americans
who buy the Repooblican agenda.


With all due regards from Rochester, NY
Jim AA2QA

In article . com,
wrote:

thanks! also, i was just reading about mixers... and getting confused.
i've run some matlab programs to figure out how you can take something
at frequency x and frequency y, and end up with an output of frequency
(x-y). one transmitter's mixer i saw took a 160mhz and 14mhz input to
get a 146mhz output. adding or multiplying them together certainly does
not yeild 146mhz. so how does that work?

You need a nonlinear function in order to get mixing behavior, and
create the sum and difference frequencies.

If you just add (e.g.) sin 160x and sin 14x, you end up with a simple
sum of sins, and no other frequencies show up - ordinary superposition.

Run the resulting sum through a nonlinear function (e.g. square it, or
take the square root, or clip it whenever its absolute value exceeds
1.0, or something like that), and take a look at the frequency content
of what you get as a result.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On Sun, 13 Mar 2005 19:32:17 -0500, "Dee Flint"
wrote:


also, when people refer to ASK and FSK, is ASK basically an audio
output that's been sent over FM? and FSK is more like CW, only to a
receiver that can monitor both mark and space (0 and 1) frequencies?

always thought amplitude-shift-keying was mainly used for morse

I believe he meant AFSK (audio frequency shift keying) vs FSK (frequency
shift keying).

The ITU emission designators for some digital modes and some typical
usage:

* A1A On/Off keying for manual reception (Morse)

* A1D ASK, Amplitude shift keying. The only recent use I have seen
is in some 433 MHz SRD (Short Range Devices)

* F1D Pure FSK (RTTY is classified as F1B)

* F2D Audio subcarrier modulated by amplitude or frequency (e.g.
1200 bit/s AX.25 packet) modulating an FM transmitter

* A2A Audio subcarrier on/off modulated by Morse code modulating
an AM transmitter (e.g. aeronautical beacons in the LF band)

* A2D Audio subcarrier modulated by amplitude or frequency
modulating an AM transmitter

* J2A Audio subcarrier on/off modulated by Morse code modulating
an SSB transmitter (many amateur multimode rigs)

* J2D Audio subcarrier modulated by amplitude or frequency (e.g.
300 bit/s AX.25 packet) modulating an SSB transmitter

On the air A1A and J2A are equivalent.

On the air F1D and J2A are equivalent and can be generated and
detected in both ways.

I hope this clarifies some of the issues.

Paul OH3LWR

"JAMES HAMPTON" wrote in message
...

"Founding Fathers" wrote in message
...

wrote in message ...
just to make sure i have it straight, if i were to transmit a sine
wave
at 146mhz, anyone listening in on 146 mhz wouldn't hear anything
....[snip]....

CW is NOT dead on two meters; anyone listening in CW mode would hear
you!
--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and
cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785)
539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle,
Pistol)


Amen brother! Outstanding signature line. Only thing I can add is the
"Cartridge Box" protects all the other boxes and is the one that is on
the
top of the big government blue state looney liberals' hit list.
Democrats
SUCK! I fear the federal government but love my country and its
Constitution. John Kerry is a liar.

The Repooblicans did a real spin on Kerry. And you bought it. They were
going to attack the AARP as a *gay* association! Good lord, if it weren't
for the many Bible-thumping modest double-digit IQ types, the Republicans
couldn't get off the ground. Fortunately, for them, there are a *lot* of
Bible-thumping double-digit IQ types and with the endless funding from big
business - well, you will discover what happens.

Since jobs moved to China, I'm thinking of buying from the company that
bought the IBM personal computer division. The profits might as well go
there as well.

Why does a guy with whom I work have a 10% service connected disability
and
cannot get VA care (despite an honorable discharge)? They keep cutting VA
funding.
He has no health insurance. He is working repairing digital cameras, so
he
is not totally brain-dead. Unfortunately, only contract work is available
these days and wages are not only stagnating, they are going down.

Canada was smart. They knew the U.S. wanted them in on the missile
defense
so Canada could pay - and Canadians are *not* stupid, unlike many
Americans
who buy the Repooblican agenda.


With all due regards from Rochester, NY
Jim AA2QA




ROTFLMAO! Take a look Sherlock. It was a troll, and *you* were the
only one who bought it. Who is your hero? Michael Moore? LOL
hahahahahhahahahahahahahahahahahah