The FCC is doing testing for the use of broadband wireless in the space
between TV channels. See
http://www.pcmag.com/article2/0,2704,2250638,00.asp.
The challenge is kind of like BPL: preventing interference with any adjacent
digital channels. From my reading, it looks like they are trying to
Hi Rud,
Wasn't the white space used for Musak or some other broadcast use years ago,
or was that on an FM subcarrier? I think it was also used for timing signals
at one time. Seems that there used to be a way to pull down the top of the
screen scan and see the information. Been a long, long,
On Sunday 20 January 2008 03:54:39 pm kh6ty wrote:
I think it was also used for timing signals
at one time. Seems that there used to be a way to pull down the top of the
screen scan and see the information.
That wasn't white space, that was the VITS. Vertical Interval Test Signal.
I have written my own code to design FIR filters using Parks-McClellan. Are
there any programs I can use to test the filter by supplying my table of
coefficients?
This is part of some SSTV code, I wrote the software as I couldn't find what I
needed out there on the web.
Simon Brown, HB9DRV
Sholto,
Patrick, I just assumed that a digital SSTV mode in 500Hz that could send a
decent size picture in a reasonable amount of time was impossible.
With a standard modulation and a standard compression scheme you are perfectly
right, but, perhaps, with some modulation as the one used by
a very powerful compression scheme, it's perhaps possible.
The compression used is .jpg or .jp2 (jpeg-2000)
For reasonybly sized pictures 10kb is minimum, 20kb is average size.
The quality does deteriorate rapidly below 20kb/picture.
The drm-modem (qam-16 mode b) has a raw troughput of
Hello Sholto,
MFSK SSTV is an analogical SSTV mode with the originality that it is a narrow
band SSTV mode (the same as MFSK) and the format of the picture is free (small
or big as you want).
It would be possible to put some RS prefix (with more bits available than for
RS ID) to define the
Jens,
Thanks for information. I had absolutely no idea there was already a narrow
band SSTV mode in MMSSTV.
Just shows no matter how long you've been a ham there is always something
new to learn!
I am guessing then that this mode would be legal now on 30m in FCC areas as
well as Region 1?
I
An example of the filter design (ignore the numbers in the toolbar please):
http://gallery.ham-radio.ch/main.php?g2_itemId=14198g2_imageViewsIndex=2
Simon Brown, HB9DRV
- Original Message -
From: Simon Brown
I have written my own code to design FIR filters using
Patrick, I just assumed that a digital SSTV mode in 500Hz that could send a
decent size picture in a reasonable amount of time was impossible. Certainly
if it is possible then it would make more sense to look at that approach.
Then error correction could also be applied...
73, Sholto KE7HPV.
Regarding Sholto's idea about using narrow SSTV on 30M, is it legal in
the USA. I am set to use MP73N . In a quick band plan check at the
ARRL it says...
General, Advanced, Amateur Extra classes:
10.100-10.150 MHz: CW, RTTY/Data
Nothing about image .
--
Andy K3UK
The rule change that enabled MFSK16 SSTV did so by stating that image modes
with a bandwidth less than 500 Hz could be used anywhere data modes were
permitted. Search the archived posts around Nov/Dec 2006 for the actual text.
So yes, it is completely legal.
-Joe, N8FQ
On Sun, 20 Jan 2008
Great, then I am going to call CQ with MMSSTV MP73-N tonight on 30M
On Jan 20, 2008 7:38 PM, Sholto Fisher [EMAIL PROTECTED] wrote:
Hi Andy,
Yes I am sure it is legal now.
I am copying Rick's response to a question about MFSK16 SSTV posted in this
group a while back:
Rick said:
Yes,
Hi Andy,
Yes I am sure it is legal now.
I am copying Rick's response to a question about MFSK16 SSTV posted in this
group a while back:
Rick said:
Yes, thanks to Mark, N5RFX, who petitioned the FCC last year, the
decision was made to allow any kind of image transmission (analog or
digital) in
I will CQ periodically tonight on 10134 USB running MMSSTV MP73-N
narrow mode. Until 04 UTC, probably at 15, 30, 45 and 00 minutes.
Andy K3UK
All,
I have an RFI problem that I'm trying to identify. It's a continuous
pulse noise that pops on every 1/2 second. The timing between each pulse
is perfect (about 0.533 seconds) and doesn't seem to change.
The noise is spread accross all HF bands and on some days it seems to
creep up into
Hello Tony,
I use a portable shortwave broadcast radio to find noise sources. I just walk
around to where it gets stronger, then fades. I have found leaky insulators on
power poles, etc. Good Luck.
Howard K5HB
- Original Message
From: Tony [EMAIL PROTECTED]
To:
Tony, a long shot butI did a search on 0.533 second pulses and
found a reference to motion detectors with 0.533 second dwell time.
Did someone get a new motion detector for Christmas ?
Andy K3UK
I did a search on --- In digitalradio@yahoogroups.com, Tony
[EMAIL PROTECTED] wrote:
All,
Patrick,
The advantage of the MFSK analog picture mode is that it is already
widely implemented, and almost all implementors of MFSK have it. Your
RSID is now available in open source C++ pocketdigi so I suspect it will
be incorporated into more programs as well. Put the two together and
the
If this turns out to be the motion detector, or anything that you
identify, please send me a screenshot or the sound file so I can put
it up on our radio interference Yahoo forum. Check out QRZ.COM to get
my email address.
Thank you!
Frank, K2NCC
http://groups.yahoo.com/group/radiointerference/
Simon,
Check this out:
http://www.dspguru.com/sw/tools/filtdsn.htm
I have tried ScopeFIR so far.
Regards,
Sergio, EA3DU
Mensaje original
De: [EMAIL PROTECTED]
Recibido: 20/01/2008 23:15
Para:
Asunto: [digitalradio] FIR Filters
I have written my own code to design FIR filters using
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