Using "Q"PSK?


John Croft, Jr., K3NJ <croft@...>
 

Hello OM/OG Warblers-

The past couple of mornings (around 1000z) has been difficult in terms of
propagation from Europe into NA . . . signal fading with qrm have combined
to make successful QSO's either "100% copy" or "nothing" . . . has anyone
"resorted" to qpsk to alleviate the condition?

In the past two years I have been active I have but one "arranged" qpsk
QSO . . . which seemed to work a trifle better . . . but wondering "how"
does one suggest or indicate to the other operator in the QSO to switch?

I have tried several times with no success. Does anyone use qpsk on a
regular basis?

73,

John, K3NJ

--
**************************************************************
* The Maryland Crofts are John (K3NJ) and Kathy (KC3T) *
* Monitoring K3VOA/R on 147.045 + Washington, DC *
* http://patriot.net/~croft *
**************************************************************


DL2AYL@...
 

Hi John,

I'm answering to QPSK-calls and mostly the om's are surprised to get an
answer, but actually I don't have the impression that it is much better than
BPSK. My software shows in the tuning indicator a cross when I'm tuned on a
QPSK-signal, seems that some softwares don't show any difference, that might
be the reason why you get not so many answers.
73's Erika/DL2AYL


John Croft, Jr., K3NJ <croft@...>
 

Hi Erika and List-

Does that mean you call "CQ" (or "cq") in QPSK from the start?

John, K3NJ

Today, DL2AYL@t-online.de sent this message:

|
| Hi John,
|
| I'm answering to QPSK-calls and mostly the om's are surprised to get an
| answer, but actually I don't have the impression that it is much better than
| BPSK. My software shows in the tuning indicator a cross when I'm tuned on a
| QPSK-signal, seems that some softwares don't show any difference, that might
| be the reason why you get not so many answers.
| 73's Erika/DL2AYL
|
|
|
|
| THE FOLLOWING APE STATIONS ARE SCHEDULED TO BE ON THE AIR:
| W3HF/QRP, 10-17 AUGUST, BOGUE BANKS IS, NC (IOTA NA-112), 20-10M
| CONTACT INFO: W3HF CBA OR W3HF@ARRL.NET
|
| Check out the 070 Club website at
| < http://hometown.aol.com/n3dqu/podxs070.htm > for
| the latest information on 070 Club activities.
| To unsubscribe from this group, send an email to:
| 070-unsubscribe@yahoogroups.com or N3DQU@aol.com.
|
|
|
| Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
|
|

--
**************************************************************
* The Maryland Crofts are John (K3NJ) and Kathy (KC3T) *
* Monitoring K3VOA/R on 147.045 + Washington, DC *
* http://patriot.net/~croft *
**************************************************************


DL2AYL@...
 

Yes, from the start in QPSK, or you chat up someone in qso with you to
switch to qpsk.
Erika/DL2AYL

----- Original Message -----
From: "John Croft, Jr., K3NJ" <croft@patriot.net>
To: <070@yahoogroups.com>
Sent: Sunday, July 14, 2002 4:21 PM
Subject: Re: [070] Using "Q"PSK?


Hi Erika and List-

Does that mean you call "CQ" (or "cq") in QPSK from the start?

John, K3NJ

Today, DL2AYL@t-online.de sent this message:

|
| Hi John,
|
| I'm answering to QPSK-calls and mostly the om's are surprised to get
an
| answer, but actually I don't have the impression that it is much
better than
| BPSK. My software shows in the tuning indicator a cross when I'm
tuned on a
| QPSK-signal, seems that some softwares don't show any difference,
that might
| be the reason why you get not so many answers.
| 73's Erika/DL2AYL
|
|
|
|
| THE FOLLOWING APE STATIONS ARE SCHEDULED TO BE ON THE AIR:
| W3HF/QRP, 10-17 AUGUST, BOGUE BANKS IS, NC (IOTA NA-112), 20-10M
| CONTACT INFO: W3HF CBA OR W3HF@ARRL.NET
|
| Check out the 070 Club website at
| < http://hometown.aol.com/n3dqu/podxs070.htm > for
| the latest information on 070 Club activities.
| To unsubscribe from this group, send an email to:
| 070-unsubscribe@yahoogroups.com or N3DQU@aol.com.
|
|
|
| Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
|
|

--
**************************************************************
* The Maryland Crofts are John (K3NJ) and Kathy (KC3T) *
* Monitoring K3VOA/R on 147.045 + Washington, DC *
* http://patriot.net/~croft *
**************************************************************



THE FOLLOWING APE STATIONS ARE SCHEDULED TO BE ON THE AIR:
W3HF/QRP, 10-17 AUGUST, BOGUE BANKS IS, NC (IOTA NA-112), 20-10M
CONTACT INFO: W3HF CBA OR W3HF@ARRL.NET

Check out the 070 Club website at
< http://hometown.aol.com/n3dqu/podxs070.htm > for
the latest information on 070 Club activities.
To unsubscribe from this group, send an email to:
070-unsubscribe@yahoogroups.com or N3DQU@aol.com.



Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/


Steve W3HF
 

Erika -

I'm answering to QPSK-calls and mostly the om's are surprised to get
an answer, but actually I don't have the impression that it is much
better than BPSK.
In theory, the QPSK-plus-FEC implementation in PSK31 is 3-6 dB
better than the BPSK option. But you would only achieve 6 dB in
an already-very-good channel. And if your print is 100% already,
you won't see it.

At the marginal cases, the improvement may be only 2-3 dB, or
less than 1/2 of one S-unit. And I believe most HF QSB is much
deeper than that, so it will be hard to see this difference too.

There's probably a class of signals that are just in the middle,
where the improvements are noticeable. But I don't know how
common they are.

My software shows in the tuning indicator a cross
when I'm tuned on a QPSK-signal, seems that some softwares don't show
any difference, that might be the reason why you get not so many
answers.
Any software that has a phase scope will see this--it's a function of
the signal, not the software. BPSK has two phase states--0 and
180 degrees--so the "perfect" signal looks like a straight line.
QPSK has four states--0/90/180/270 degrees--so the signal looks
like a cross.

I think the problem is that most people don't know what the phase
scope means, and either don't use it or don't recognize what it is
telling them. No one is expecting QPSK, so they don't even think
to try it.

Steve
W3HF


Dieter, DL2RR <dl2rr@...>
 

Hi to all,

in addition to Steves notes it is to be said that the bandwidth of the
software in QPSK is usually reduced to 4 Hz (7 Hz at BPSK). Some, all older,
TRX are not stably enough to hold the frequncy during one over like my
IC735. In this case QPSK is a degradation for me. But with many idles
between the text there is a chance that the AFC can correct the drift. This
concerns both the sending and the receiving side.


73's de Dieter - DL2RR

----- Original Message -----
From: John Croft, Jr., K3NJ <croft@patriot.net>
To: 070 List <070@yahoogroups.com>
Sent: Sunday, July 14, 2002 1:30 PM
Subject: [070] Using "Q"PSK?


:
: Hello OM/OG Warblers-
:
: The past couple of mornings (around 1000z) has been difficult in terms of
: propagation from Europe into NA . . . signal fading with qrm have combined
: to make successful QSO's either "100% copy" or "nothing" . . . has anyone
: "resorted" to qpsk to alleviate the condition?
:
: In the past two years I have been active I have but one "arranged" qpsk
: QSO . . . which seemed to work a trifle better . . . but wondering "how"
: does one suggest or indicate to the other operator in the QSO to switch?
:
: I have tried several times with no success. Does anyone use qpsk on a
: regular basis?
:
: 73,
:
: John, K3NJ
: