Why? Because your digital voice QSO sounds like noise to SSBers?
From: John Becker [EMAIL PROTECTED]
Reply-To: digitalradio@yahoogroups.com
To: digitalradio@yahoogroups.com
Subject: RE: [digitalradio] The digital throughput challenge on HF
Date: Sun, 27 Aug 2006 20:29:05 -0500
You should try
You should try DIGITAL VOICE once.
There is 1000% chance that your QSO will be
QRM'ed
At 04:43 AM 8/25/2006, you wrote:
The problem is QRM. Consisting of PACTOR, MFSK, OLIVIA, PSK31, and on 30
meters also SSB signals coming on frequency during your qso.
Need a Digital mode QSO? Connect
: RE: [digitalradio] The digital throughput challenge on HF
Oh my...you are right about the baud rates of MT63...I was going from memory
and I have the written down.
The only problem with on-the-air testing is that you Never HAVE THE SAME
CONDITIONS and you can do that with a simulator
How does the crest factor relate to the mean power vs the peak power? It
doesn't seem correct to add 3 to that figure to come up with the crest
factor.
Patrick has the peak and mean power for the various modes listed in the
documentation for Multipsk, but I am not clear how to convert them to
-Original Message-
From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED]
Sent: Wednesday, August 23, 2006 8:17 PM
To: digitalradio@yahoogroups.com
Subject: RE: [digitalradio] The digital throughput challenge on HF
At 04:29 PM 8/23/2006, you wrote:
It in deed would. That is the reason Pactor
Rick,
My explanation was for sinusoids not rectangular waves, our radios transmit
sinusoids. You are correct about rectangular waves they would have a crest
factor of 1 in linear terms or voltage terms, and 0B in non-linear or power
terms. Yes MT63 has a crest factor of 13dB. It is very
(taking into
account that the figures are not very precise, but sufficient for comparizons).
73
Patrick
- Original Message -
From: KV9U
To: digitalradio@yahoogroups.com
Sent: Thursday, August 24, 2006 4:12 PM
Subject: Re: [digitalradio] The digital throughput challenge on HF
] The digital throughput challenge on HF
To be onest, Walt, I don't see Rick's claim of such a good performance
level for MT-63. If you look at his presentation on comparing several
modes with Pactor, at:
http://winlink.org/Presentations/RFfootprints.PDF
he seems to suggest that all the non-ARQ sound
-Original Message-
From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED]
Sent: Thursday, August 24, 2006 9:13 AM
To: digitalradio@yahoogroups.com
Subject: Re: [digitalradio] The digital throughput challenge on HF
[stuff deleted]
If you want to broadcast a message from one to many
If I were a company technology officer, of a company who's purpose was
developing communications technology...or the technology officer for
amateur radio, I would be very dis-heartened at the data
protocols/modes/modems produces as well as the HF E-Mail applications
developed. None are really
@yahoogroups.com [mailto:[EMAIL PROTECTED]
Sent: Wednesday, August 23, 2006 11:52 AM
To: digitalradio@yahoogroups.com
Subject: [digitalradio] The digital throughput challenge on HF
If I were a company technology officer, of a company who's purpose was
developing communications technology...or the technology
be surprised.
73,
Walt/K5YFW
-Original Message-
From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED]
Sent: Wednesday, August 23, 2006 1:57 PM
To: digitalradio@yahoogroups.com
Subject: Re: [digitalradio] The digital throughput challenge on HF
Mark,
Why do the Pactor modes work
It in deed would. That is the reason Pactor and Amtor
work so well. It's the AQR - even with the hi S/N needed.
I got into Amtor in the early days when the KIT BOARD
was over 500 bucks. Ask HB9AVK what he thinks of the
AQR modes and Amtor in general. Or G3GPS. A lot
of us old RTTY'ers played with
Mark,
If what you say was true, it would be easy to have sound card modes that
compete with Pactor modes. From studies that I have seen, Amtor can work
down around zero db S/N. Same with Pactor I. Some claim a bit below 0
db. In fact one recent test claimed that RTTY was better than PSK31 for
To be onest, Walt, I don't see Rick's claim of such a good performance
level for MT-63. If you look at his presentation on comparing several
modes with Pactor, at:
http://winlink.org/Presentations/RFfootprints.PDF
he seems to suggest that all the non-ARQ sound card modes (e.g, PSK-31,
MT-63)
At 04:29 PM 8/23/2006, you wrote:
It in deed would. That is the reason Pactor and Amtor
work so well. It's the AQR - even with the hi S/N needed.
There is some value to ARQ, I wonder how we would quantify the
advantage? In a point to point link I think it would be easy, but in a
point to
Note also in Figure 6, the real world test by using distance on 80
meters daytime. The worst performance was by Amtor, followed by Pactor 1
and closely by PSK31. The best performer was RTTY at these slow speeds
and he gives his explanation as why he believes this occurs. It sounds
reasonable to
Hi Mark,
The ARQ is really important. You really should have this for serious
messaging via RF and must have it if you want to interface with a
mailbox system or internet. Even one bad character trashes everything
when negotiating a menu. Those who are OT's with Amtor know what I mean.
I used
At 10:33 PM 8/23/2006, you wrote:
I am not very knowledgeable on CRF (Crest Factors). Can you give us an
idea of converting peak power/average power into CRF?
Using powers, crest factor = Peak Instantaneous Power / Average Power. A
more piratical way of measuring crest factor is (PEP/Average
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