[FADCA] Transmittal speed

Mon, 17 Feb 2003 19:46:52 -0500

Bob,

300 baud is the maximum rate for packet on HF and that turns out to be about
1.5KHz wide.  Pactor 1 runs 100-200 bits per second and about 350 Hz wide.
Pactor 2 runs from 200 to 800 bits per second and is 500 Hz wide. Pactor 3
Runs 200 - 3600 bits per second and is up to 2.2 KHz wide. Speed for all
pactor is adjusted automatically to best fit conditions.

A note:  There is consideration by the ARRL and FCC in future band planning
that may  minimize or perhaps ban 300 Baud HF packet at least on some HF
bands.  This mode is inefficient in bandwidth vs error-free bits delivered.

73,

Rick KN6KB

-----Original Message-----
From: [email protected] [mailto:[email protected]]On
Behalf Of Stacey & Bob H.
Sent: Monday, February 17, 2003 1849 PM
To: [email protected]
Subject: Re: [FADCA] Transmittal speed

That answered it. Looks like I will go right to Pactor III. I had heard that
the maximum speed on HF is 300b is that true or is it for some bands?

Thanks

Bob N4WFH

----- Original Message -----
From: "bud thompson" <[email protected]>
To: <[email protected]>
Sent: Sunday, February 16, 2003 11:17
Subject: Re: [FADCA] Transmittal speed

> Bob:
>
> The HF transfer of the 32K message was done on PacTOR 3.  The link to
WB5KSD
> in Dallas was good and the transmission speed reached an indicated 3200BPS
> for most of the file transfer. PacTOR modes are adaptive and change rates
> depending on throughput/conditions. Once the transfer started, my Airmail
> screen indicated it would take less than one minute. (<1 min)
>
> The upper rates of PacTOR 3 require a 2.4KHz bandwidth. It is a multi-tone
> mode, not just two-tone M/S.
>
> PacTOR 2 can attain up to 800BPS and PacTOR 1 maxes out at 200BPS. Both
are
> only two-tone M/S modes and work within a 500Hz bandwidth.
>
> 3200 is the max rate for PacTOR 3. It steps down from there to 2800, 1400,
> (1200?), 800, 600, 200 - ( think that is the progression) depending on
> conditions.  Most of the PacTOR 3 links on my WL2K are 1400 or greater...
Of
> course I don't know this unless I'm watching which isn't all the time.
After
> almost two months of WL2K operation now, I'd estimate that 15 percent of
the
> P3 transfers are at max speed, 60 percent at the next step down. This is
on
> any band 40,30,20, 17,and 15M where I allow P3 connects.  My regular users
> are at distances from 100 miles to more than 3500 miles.  In January I had
a
> regular user while he took a week or more crossing the Indian Ocean in his
> sailboat, but he was using PacTOR 2.
>
> My stats show that since Jan 1 about 40-45% of the connects are PacTOR 3,
> 35% PacTOR 2 and the rest PacTOR 1.
>
> I assume the rate that is shown on my screen during the transfers is the
> ASCII transfer rate, so the effective throughput would be faster yet
> depending on how much compression is being used. At a 40% compression, a
> 3200 rate would be 1.4x that much effective or nominally 5KB.  I also
assume
> the posted rate is the actual transmission rate which would have to be
> reduced when the effective rate is determined as these are QRQ modes, not
> full duplex.
>
> Of course the 80 seconds on my transfer to Dallas  included all the
> systematic overhead as well.
>
> Rick KN6KB can weigh in here to straighten out any kinks I just made.
>
> bud
>
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> ----- Original Message -----
> From: "Stacey & Bob H." <[email protected]>
> To: <[email protected]>
> Sent: Sunday, February 16, 2003 09:49
> Subject: [FADCA] Transmittal speed
>
>
> > Bud Wrote:
> >
> > Yesterday I sent a ham-to-e-mail message with two attachments. One was
an
> MS
> > Word file (a 30K binary file), the other a small DOS.txt file. The
actual
> > text in the e-mail message was only a reference to the testing. The
total
> > e-mail message was just over 32Kbytes. From my home Airmail set up in
> > Deltona on 20M I linked with WB5KSD, a frequency/band scanning WL2K
> station
> > near Dallas, TX. I got lucky and made the link in about 15 seconds - it
> > would have taken 45 seconds had I missed his scanning the frequency the
> > first time. Once linked the entire 32K message was sent and we were
> > disconnected in about 80 seconds. I then walked across the shack about
10
> > ft to my XYL's computer and the e-mail message was in her in folder.
> >
> > Bob: Bud at what baud rate did you pass a 32k file in 80sec? At 1200
baud
> it
> > would approximately 9 minutes.
> >
> > Bob N4WFH
> >
> >
> > _______________________________________________
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> > [email protected]
> > http://mailman.qth.net/mailman/listinfo/fadca
> >
>
>
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