Heard a Digi Mode, what is it?
 

Last couple evenings heard on 3584 a digital mode that sounds and
looks like MFSK on the waterfall except the bandwidth is 1000 hz. None
of my various programs will decode it. Anyone have a clue as to what
it may be and what SW is available to use it. TIA Nigel VE3ELQ

"VE3ELQ" wrote in message
...
Last couple evenings heard on 3584 a digital mode that sounds and
looks like MFSK on the waterfall except the bandwidth is 1000 hz. None
of my various programs will decode it. Anyone have a clue as to what
it may be and what SW is available to use it. TIA Nigel VE3ELQ

Nigel maybe compare it to the digital on-line sounds at these URL's
http://www.wunclub.com/sounds/

http://www.kb9ukd.com/digital/

http://rover.wiesbaden.netsurf.de/~s.../DIG_intro.htm

Good Luck
--
Caveat Lector

In article ,
VE3ELQ wrote:


Last couple evenings heard on 3584 a digital mode that sounds and
looks like MFSK on the waterfall except the bandwidth is 1000 hz. None
of my various programs will decode it. Anyone have a clue as to what
it may be and what SW is available to use it. TIA Nigel VE3ELQ

There is a new mode being experimented with - I've seen it discussed
in the Yahoo groups digitalradio and mfsk. Haven't tried it yet myself.
--

jhhaynes at earthlink dot net

At 1000Hz wide? How about MT63?

Cheers Bob VK2YQA

VE3ELQ wrote:
Last couple evenings heard on 3584 a digital mode that sounds and
looks like MFSK on the waterfall except the bandwidth is 1000 hz. None
of my various programs will decode it. Anyone have a clue as to what
it may be and what SW is available to use it. TIA Nigel VE3ELQ

On Fri, 07 Jan 2005 14:39:36 +1100, Bob Bob
wrote:
I tried that and no go with MixW2.12, the brackets are 500hz wide in
that mode. It was there again last night on 3583 along with some good
DX that I worked, a G4 and some RUs, the band was long skip and
reasonably quiet. Still dont know what it is but at 1000hz wide its
not narrow band and it was well into the PSK region with the PSK31
signals all below it. It might become a problem unless they move up or
down a little and leave 3 khz free for the truly narrow band modes.
73s Nigel VE3ELQ

At 1000Hz wide? How about MT63?

Cheers Bob VK2YQA

It's called "Olivia." It's a MFSK variant with multiple tones and bandwidth
settings which are currently user selectable The default setup is 32 tones
with a bandwidth of 1000Hz. The mode uses forward error correction allowing
weak signal reception. The made is being developed by Pawel Jalocha,
SP9VRC.



"VE3ELQ" wrote in message
...
On Fri, 07 Jan 2005 14:39:36 +1100, Bob Bob
wrote:
I tried that and no go with MixW2.12, the brackets are 500hz wide in
that mode. It was there again last night on 3583 along with some good
DX that I worked, a G4 and some RUs, the band was long skip and
reasonably quiet. Still dont know what it is but at 1000hz wide its
not narrow band and it was well into the PSK region with the PSK31
signals all below it. It might become a problem unless they move up or
down a little and leave 3 khz free for the truly narrow band modes.
73s Nigel VE3ELQ

At 1000Hz wide? How about MT63?

Cheers Bob VK2YQA

"Jim" writes:
It's called "Olivia." It's a MFSK variant with multiple tones and bandwidth
settings which are currently user selectable The default setup is 32 tones
with a bandwidth of 1000Hz. The mode uses forward error correction allowing
weak signal reception. The made is being developed by Pawel Jalocha,
SP9VRC.

I wonder why anyone is messing with these modes instead of doing DSSS,
now that we can digitally-process the daylights out of the received
signal instead of messing with analog filter banks or whatever. I've
been hoping for something even slower than PSK31, spread over an
entire ham band or even multiple bands. I'd think something like that
would be ultra-reliable through just about any amount of interference.

DSSS is nowhere near the best modulation format in the presence of
narrowband
interference. OFDM is far better suited in this case as was shown in ADSL
trials (examing the effects of cable crosstalk). We found the same during
our
amateur spread specturm experiments in Dallas in the 902-928 MHZ band in
the late 1990s where DSSS was far inferior to frequency hopping with bad
channel notching.

-- Tom, N5EG




"Paul Rubin" wrote in message
...

SNIP


I wonder why anyone is messing with these modes instead of doing DSSS,
now that we can digitally-process the daylights out of the received
signal instead of messing with analog filter banks or whatever. I've
been hoping for something even slower than PSK31, spread over an
entire ham band or even multiple bands. I'd think something like that
would be ultra-reliable through just about any amount of interference.

"TOM" writes:
DSSS is nowhere near the best modulation format in the presence of
narrowband interference. OFDM is far better suited in this case as
was shown in ADSL trials (examing the effects of cable
crosstalk). We found the same during our amateur spread specturm
experiments in Dallas in the 902-928 MHZ band in the late 1990s
where DSSS was far inferior to frequency hopping with bad channel
notching.

I was thinking in terms of DSSS on the HF bands, for reliable, long
haul data traffic at very low bit rates. Am I nuts?

Well, if anyplace has severe narrowband interference, I would think that
HF would surely be it.

-- Tom, N5EG


"Paul Rubin" wrote in message
...
"TOM" writes:
DSSS is nowhere near the best modulation format in the presence of
narrowband interference. OFDM is far better suited in this case as
was shown in ADSL trials (examing the effects of cable
crosstalk). We found the same during our amateur spread specturm
experiments in Dallas in the 902-928 MHZ band in the late 1990s
where DSSS was far inferior to frequency hopping with bad channel
notching.

I was thinking in terms of DSSS on the HF bands, for reliable, long
haul data traffic at very low bit rates. Am I nuts?