Recently I have heard references from multiple sources about 9.6kb PSK
activity on HF bands.

What's the deal on this? Is it a wide, multi-stream mode like Q15x25 mode?

It sounds illegal, but lots of things sound illegal if you are not familiar
with the facts. That's me... I am not knowlegable about PSK packet. I do
have a "flexible" modem though, that will allow me to operate PSK packet at
a variety of baud rates... Isn't 1200 baud the limit on 10 meters, and 300
baud lower down?

Somebody straighten me out on this, please... I'm cornfused.

Charles Brabham, N5PVL
Director: USPacket.Net
http://www.uspacket.net

On Fri, 28 Nov 2003 03:26:01 GMT, "charlesb"
wrote:

Recently I have heard references from multiple sources about 9.6kb PSK
activity on HF bands.

I assume this refers to 9600 bit/s.


What's the deal on this? Is it a wide, multi-stream mode like Q15x25 mode?

It sounds illegal, but lots of things sound illegal if you are not familiar
with the facts. That's me...

A 9600 bit/s QPSK signal fits nicely within the same bandwidth
occupied by an AM phone transmission, with 8PSK (or 8QAM) the signal
would fit into the bandwidth of SSB phone transmissions. If the
bandwidth limit allows AM or SSB, then what is the problem with other
modes with similar bandwidths ?

I am not knowlegable about PSK packet. I do
have a "flexible" modem though, that will allow me to operate PSK packet at
a variety of baud rates... Isn't 1200 baud the limit on 10 meters, and 300
baud lower down?

That is a purely US specific issue.

Anyway, 1200 baud or 1200 symbols/s is quite capable of transmitting
9600 bit/s provided that the SNR is good. It requires that 8 bits are
transmitted within each symbol, i.e. each symbol can have 256 distinct
states. While 256PSK would hardly be practical, 256QAM might work with
high SNR and low phase distortion line of sight paths.

256QAM requires that the receiver must be able to detect more than 20
distinct states in both I and Q direction, thus quite small errors
will spoil the reception. However 64QAM (6 bits/symbol) are widely
used in Europe on the COFDM subcarriers used in digital television.

Paul OH3LWR

"Paul Keinanen" wrote in message
...
On Fri, 28 Nov 2003 03:26:01 GMT, "charlesb"
wrote:

Recently I have heard references from multiple sources about 9.6kb PSK
activity on HF bands.

I assume this refers to 9600 bit/s.


What's the deal on this? Is it a wide, multi-stream mode like Q15x25
mode?

It sounds illegal, but lots of things sound illegal if you are not
familiar
with the facts. That's me...

A 9600 bit/s QPSK signal fits nicely within the same bandwidth
occupied by an AM phone transmission, with 8PSK (or 8QAM) the signal
would fit into the bandwidth of SSB phone transmissions. If the
bandwidth limit allows AM or SSB, then what is the problem with other
modes with similar bandwidths ?


Well except that for standard PSK enthusiasts tout it's exceptionally narrow
bandwidth thus allowing more conversations in a given space than even CW.
What point is there in creating a wide digital mode?

Dee D. Flint, N8UZE

"Dee D. Flint" wrote

Well except that for standard PSK enthusiasts tout it's exceptionally narrow
bandwidth thus allowing more conversations in a given space than even CW.
What point is there in creating a wide digital mode?

Dee D. Flint, N8UZE

Single channel PSK has nothing in common with high bandwidth information
transport. What one group touts may be exactly opposite of what another
group touts. Sometimes 31 bps at 31 baud is good enough, other times
3600 bps at 50 baud is what is needed.

The point in creating a wide digital mode, is to increase throughput per second.

"Dee D. Flint" wrote in message
gy.com...

What point is there in creating a wide digital mode?

More throughput, error correction for 100% copy, ability to transfer binary
files. ( Q15x25 guys like to send JPEG's back 'n forth, kind of like SSTV,
except the pics come through 100% good. )

Obviously any wide mode is overkill for keyboard QSO's, but there's a whole
world of other things that hams want or need to do, and some of them require
more bandwidth.

There are a lot of pro's and cons related to utilizing the wide modes for
any purpose. I don't think we will have to worry about them becoming so
popular that they will squeeze out everybody else.

Charles Brabham, N5PVL
Director: USPacket.Net
http://www.uspacket.net

"charlesb" wrote in message
. com...
More throughput, error correction for 100% copy, ability to transfer
binary
files. ( Q15x25 guys like to send JPEG's back 'n forth, kind of like SSTV,
except the pics come through 100% good. )


Charles Brabham, N5PVL
Director: USPacket.Net
http://www.uspacket.net


Where are the Q15x25 QSOs going on. I have MixW, which should work this
mode, but I am not aware of ever hearing it on the HF bands. Is this a
VHF/UHF only mode?

73 - Mike - K9JRI

"Mike Blake" wrote in message
gy.com...

Where are the Q15x25 QSOs going on. I have MixW, which should work this
mode, but I am not aware of ever hearing it on the HF bands. Is this a
VHF/UHF only mode?


It's intended for HF, but works great on VHF/UHF too. Operating freqs listed
in the pages that follow.


http://home.att.net/~ronchap/q15x25modes/q15x25.htm

http://sharon.pi8zaa.ampr.org/mirror...25/Q15X25.html

There is also a Yahoo group named "Q15x25" that is a great source of info on
operating this digital mode.

Briefly: Q15x25 uses 15 PSK streams at 88.xxx baud each, theoretically
giving you around 2500 baud. That's where the 15 and 25 in the name come
from. It butts right up against the legal limits of bandwidth, but doesn't
cross those limits and is so it legal, despite doubts that some have
expressed in the past.

Q15x25 operates exactly like packet. It's a connected mode, and if a frame
gets through at all, it gets through intact. From what I can tell, the most
popular activity among Q15x25 enthusiasts is to swap JPEG images on the air,
kind of like SSTV but with error-correction so the pics always come through
clean.

There are versions for Linux and Winders.

My on the air experience with Q15x25 is that it works great when you have
clear spectrum, but under noisy conditions is no better or worse than 300
baud packet! - Except of course it takes up several times as much spectrum
to do so. Q15x25 will not pull out weak signals you can't hear or any of
that kind of stuff. On the other hand, under decent operating conditions it
can be pretty fast.

I also have discovered that by boosting the TXD up to 800-1000 MS or more,
you can conduct Q15x25 QSO's over a normal VHF voice repeater. A nice 2500
baud data transfer system for emergency use anywhere there is a voice
repeater... Admittedly not ideal, but still a big step up from nothing.

I remember reading a few weeks back that the author/authors of Q15x25 were
currently working on a new version, so it appears the mode is alive and
well, if not popular due to it's width. It really is hard to find a good
place to operate Q15x25 on busy freqs.

That's the problem with the wide modes, I guess. TANSTAAFL

Charles Brabham, N5PVL
Director: USPacket.Net
http://www.uspacket.net

"Mike Blake" wrote in message
gy.com...

Where are the Q15x25 QSOs going on. I have MixW, which should work this
mode, but I am not aware of ever hearing it on the HF bands. Is this a
VHF/UHF only mode?


It's intended for HF, but works great on VHF/UHF too. Operating freqs listed
in the pages that follow.


http://home.att.net/~ronchap/q15x25modes/q15x25.htm

http://sharon.pi8zaa.ampr.org/mirror...25/Q15X25.html

There is also a Yahoo group named "Q15x25" that is a great source of info on
operating this digital mode.

Briefly: Q15x25 uses 15 PSK streams at 88.xxx baud each, theoretically
giving you around 2500 baud. That's where the 15 and 25 in the name come
from. It butts right up against the legal limits of bandwidth, but doesn't
cross those limits and is so it legal, despite doubts that some have
expressed in the past.

Q15x25 operates exactly like packet. It's a connected mode, and if a frame
gets through at all, it gets through intact. From what I can tell, the most
popular activity among Q15x25 enthusiasts is to swap JPEG images on the air,
kind of like SSTV but with error-correction so the pics always come through
clean.

There are versions for Linux and Winders.

My on the air experience with Q15x25 is that it works great when you have
clear spectrum, but under noisy conditions is no better or worse than 300
baud packet! - Except of course it takes up several times as much spectrum
to do so. Q15x25 will not pull out weak signals you can't hear or any of
that kind of stuff. On the other hand, under decent operating conditions it
can be pretty fast.

I also have discovered that by boosting the TXD up to 800-1000 MS or more,
you can conduct Q15x25 QSO's over a normal VHF voice repeater. A nice 2500
baud data transfer system for emergency use anywhere there is a voice
repeater... Admittedly not ideal, but still a big step up from nothing.

I remember reading a few weeks back that the author/authors of Q15x25 were
currently working on a new version, so it appears the mode is alive and
well, if not popular due to it's width. It really is hard to find a good
place to operate Q15x25 on busy freqs.

That's the problem with the wide modes, I guess. TANSTAAFL

Charles Brabham, N5PVL
Director: USPacket.Net
http://www.uspacket.net

"charlesb" wrote in message
. com...
More throughput, error correction for 100% copy, ability to transfer
binary
files. ( Q15x25 guys like to send JPEG's back 'n forth, kind of like SSTV,
except the pics come through 100% good. )


Charles Brabham, N5PVL
Director: USPacket.Net
http://www.uspacket.net


Where are the Q15x25 QSOs going on. I have MixW, which should work this
mode, but I am not aware of ever hearing it on the HF bands. Is this a
VHF/UHF only mode?

73 - Mike - K9JRI

"Dee D. Flint" wrote

Well except that for standard PSK enthusiasts tout it's exceptionally narrow
bandwidth thus allowing more conversations in a given space than even CW.
What point is there in creating a wide digital mode?

Dee D. Flint, N8UZE

Single channel PSK has nothing in common with high bandwidth information
transport. What one group touts may be exactly opposite of what another
group touts. Sometimes 31 bps at 31 baud is good enough, other times
3600 bps at 50 baud is what is needed.

The point in creating a wide digital mode, is to increase throughput per second.