The VHF and UHF bands have explicit bandwidth limits on data emissions and
image has a bandwidth limit on HF. Unfortunately, image transmission benefits
the most from increased bandwidth. This maybe a group concerned mainly with
RTTY and data but there are other modes that woud benefit from
(was Re: ARRL wake up
..)
--- In digitalradio@yahoogroups.com, John B. Stephensen [EMAIL PROTECTED]
wrote:
47cfr97.307(f)(2) limits the bandwidth of all transmissions in the
phone/image segments to that of AM or SSB communications quality audio
which is usually interpreted as 3 kHz
The international broadcaster's signals are wider (5-10 kHz vs. 2.5 kHz) so an
AM or NBFM IF filter and a wider audio bandwidth is required to feed the sound
card. See drm.sourceforge.net and www.drmrx.org for software. Many radios won't
allow the BFO to be offset far enough to receive SSB this
What you're proposing is regulation by bandwidth. Once you're in a QSO with
another station it shouldn't matter what you send. The only issue is where the
different band segments for the different bandwidths are located.
73,
John
KD6OZH
- Original Message -
From: n6vl
To:
The original ARRL regulation by bandwidth proposal put wide data in the same
band segments with image and voice transission. Their members seem to have
convinced them otherwise. Perhaps they need to hear from supporters of
regulation by bandwidth.
73,
John
KD6OZH
- Original Message
The ARRL deleted other changes below 30 MHz, but wants to change the
voice/image segment bandwidth from the existing communications quality voice
to 3 kHz.
73,
John
KD6OZH
- Original Message -
From: kv9u
To: digitalradio@yahoogroups.com
Sent: Saturday, March 24, 2007 19:50
to pass, it would not be possible to get that changed for a very long time.
73,
Rick, KV9U
John B. Stephensen wrote:
The ARRL deleted other changes below 30 MHz, but wants to change the
voice/image segment bandwidth from the existing communications
quality voice to 3 kHz
The bandwidth limit applies only to the phone segments.
73,
John
KD6OZH
- Original Message -
From: expeditionradio
To: digitalradio@yahoogroups.com
Sent: Friday, March 16, 2007 01:35 UTC
Subject: [digitalradio] Re: no bandwidth limit
There is no finite bandwidth limit
The 3kHz bandwidth is dissappointing.
73,
John
KD6OZH
- Original Message -
From: DuBose Walt Civ AETC CONS/LGCA
To: digitalradio@yahoogroups.com
Sent: Friday, February 23, 2007 19:17 UTC
Subject: [digitalradio] ARRL Seeks Comments on New HF Digital Protocol
Look at http://www.fcc.gov/sptf/reports.html to see what the FCC thinks.
Their
spectrum policy report states:
As a general proposition, flexibility in spectrum regulation is critical to
improving
access to spectrum. In this context, flexibility means granting both
licensed users
and
Pactor-3 is as legal as it was before the Omnibus RO, but unless you are
sending a fax it is restricted to the new RTTY/Data segments.
73,
John
KD6OZH
- Original Message -
From: Roger J. Buffington
To: digitalradio@yahoogroups.com
Sent: Wednesday, November 29, 2006 02:03 UTC
If radiated power is not limited, data rate is directly proportional to
bandwidth, but the maximum data rate per kHz depends on the amount of time
(multipath) spreading and amount of frequency (Doppler) spreading. NVIS has
a multipath spread of 6-12 ms and there needs to be a gap between symbols
Dopper shift increases with ionospheric disturbance and the solar geophysical
reports always show that the effect is more pronounced in northern latitudes. I
don't know a lot about the physics of the ionosphere but I assume that it's for
the same reason the aurora always occurs near the poles.
The FCC rules provide the following definitions for fax:
Image. Facsimile and television emissions having designators with
A, C, D, F, G, H, J or R as the first symbol; 1, 2 or 3 as the second
symbol; C or F as the third symbol; and emissions having B as the
first symbol; 7, 8
The FCC rules provide the following definitions for fax:
Image. Facsimile and television emissions having designators with
A, C, D, F, G, H, J or R as the first symbol; 1, 2 or 3 as the second
symbol; C or F as the third symbol; and emissions having B as the
first symbol; 7, 8
be deduced from the fact that they carry independent
streams of bits.
Rick N6RK
John B. Stephensen wrote:
I should have said that the subcarriers must be orthogonal because
Pactor-3 uses each subcarrier to send an independent stream of bits. In
someone else's email they verified
To: digitalradio@yahoogroups.com
Cc: digitalradio@yahoogroups.com
Sent: Wednesday, November 22, 2006 19:49 UTC
Subject: Re: [digitalradio] Re: OFDM data is Emission Designator D1D
John B. Stephensen wrote:
its orthogonal because the state
of each subcarrier is independent
The key appears to be whether the information is printed immediately or not. In
97.3, RTTY is defined as Narrow-band direct-printing telegraphy. So text is B
if it is printed or D if it is not printed.
It's interesting that emission types B7W, B8W and B9W (ISB) are still allowed,
so you can
The FCC uses the phrase quantitized or digital information in the definitions
in part 2 so anything encoded into discrete levels of amplitude, phase or
frequency is digital.
The definitions in part 97 were probably very clear when they were written. It
looks like they took amateur radio terms
The problem with NVIS is that there are a lot of
pathsover whichthe transmittedsignalcan reach the
receiver.When DRM was tested, theymeasured a 7 ms delay spread in an
equatorial region and I've seen reports published on the Internet showing up to
13 ms. In near-polar regions, there is
The ARRL told me that any data transmission mode
(defined as computer to computer file transfer)wider than 500 Hz would be
prohibited on all HF bands if the rules changes go into effect. Image
transmission bandwidth is unchanged. They also said that they are working to
convince the FCC to
I specificly asked about Pactor III and was told
thatit would be illegal. This is why the ARRL is upset with the
FCC.
73,
John
KD6OZH
- Original Message -
From:
DuBose Walt Civ AETC CONS/LGCA
To: digitalradio@yahoogroups.com
Sent: Tuesday, October 31, 2006
The current rules restrict emissionsin
various requency segents bytye of information being
transmitted(RTTY, data, phone, image) and usuallyallow either analog
or digital transmission (this is the second character in the emission
designator).
73,
John
KD6OZH
.
- Original Message
I only recently joined this list so here is some
more specific information on 6-meter wideband digital testing.
TheARRL, at therequest ofthe HSMM WG,asked for and
was granted a license to test digital modes up to 200 kHz wideon 6
meters.Agoal of 256 kbps was set as this wouldallow decent
Even though the license authorized 50.3-50.8 MHz, I stayed away from the AM
calling frequency. The only frequency used so far is 50.7 MHz, so the signal
covers 50.625-50.775 MHz and the FCC occupied bandwidth (-27 dB) is within
50.6-50.8 MHz.
73,
John
KD6OZH
- Original Message -
It would be reasonable to allowswitching
between voice, data and image in the phone segment, all using the same
bandwidth. This would cause no interference to adjacent frequencies and is the
essence of regulation by bandwidth.
73,
John
KD6OZH
- Original Message -
From:
The FCC RO makes some big changes on HF. It limits the bandwidth of data
transmission to 500 Hz below 30 MHz.. It also states that data and image
transmission were never authorized in the same HF frequency segments so
data
in the phone/image segments seems to be prohibited. Considerable
The FCC RO makes some big changes on HF. It limits the bandwidth of data
transmission to 500 Hz below 30 MHz.. It also states that data and image
transmission were never authorized in the same HF frequency segments so data
in the phone/image segments seems to be prohibited. Considerable spectrum
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