Hi Patrick.
Thanks for the info. I hope it was useful to the othes too. That's the
reason I discuss it on the list.
Pawel's input processor does basically the following.
- Splits input stream to chunks that half overlap
- Applies a window to the chunks.
- Computes FFT
- Averages each FFT bin
Operating digital is something that most of us seem to learn more or
less on our own, with the (huge) help of the internet, with all of its
resources. One of the things that frequently surprises me are some of
the myths and misconceptions that are common among digital ops. Here
are a few.
[1] Never run ALC or audio compression, keep your signal 100% linear.
[2] When using varicode modes such as PSK type in lowercase - it's much
faster and results in fewer errors.
[3] All soundcards are not equal. Get a decent soundcard, minimum(-ish)
standard being the Creative Audigy.
[4] GOTO
Simon Brown wrote:
[1] Never run ALC or audio compression, keep your signal 100% linear.
So true. Fortunately, most people seem to have learned this.
Re: filtering - a good rig with a high dynamic range + good soundcard
may not need so much filtering as (say) and FT-817. With my
GREAT Log Andy...tnx.
Walt/K5YFW
-Original Message-
From: digitalradio@yahoogroups.com
[mailto:[EMAIL PROTECTED] Behalf Of Andrew O'Brien
Sent: Monday, January 08, 2007 7:05 PM
To: digitalradio@yahoogroups.com
Subject: [digitalradio] some digital spots
FYI
DX de K3UK:
Ralph Mowery:
watching many hours of RTTY with only 170 hz between
the tones, I have seen one tone fade and come back in
several seconds, then the other tone will do the same
thing.
It sounds like selective fading Ralph. You can often see this
in the waterfall of wide modes like MT63. The
I must say that for soundcard modes purity of signal is a zillion % more
important that signal strength.
IMO if the band is open you'll work the guy with 5W.
Simon Brown, HB9DRV
- Original Message -
From: John Becker [EMAIL PROTECTED]
1. Power does not matter for digital modes.
Hi,
Version 0.483 is out.
http://rfsm2400.narod.ru
or
http://rfsm2400.aanesland.com
Changes in version 0.483.
--
Change packets monitor work.
View CALLSIGNS in all signal blocks.
73 de LA5VNA Steinar
Hello Sergio,
Of course, if the channel (+ your receiver and your non-linear filters) would
be completly equalized, it will come much better towards decoding. However, it
would remain QRN (parasitics) and QRM which could not be equalized as they are
completly random. Without QRN and QRM, the
I agree with Roger that power does matter, and, like him don't understand why
some ops insist on running low power in
less than optimum conditions the idea is to get the message through. I have a
similar complaint with those hams who go out and work a 2M public service event
, using minimal
The problem with running power in PSK mode, would mostly go away, if one is
careful about how much audio drive he is applying to the signal. To ensure
there are no side lobes on the waterfalls of other ops, you much insure you
have the input to the rig set as low as possible, and to not exceed
I don't think you should run these on the 480 as they are in the AF chain and
will always degrade the information you need to decode the signal.
It's not what you hear, it's what your software can decode. Let the software do
the work...
Simon Brown, HB9DRV
- Original Message -
--- In digitalradio@yahoogroups.com, Simon Brown [EMAIL PROTECTED]
wrote:
I don't think you should run these on the 480 as they are in the AF
chain and will always degrade the information you need to decode the
signal.
It's not what you hear, it's what your software can decode. Let the
Some stations also suffer from RF feedback at higher power levels, so
cutting the power back reduces the chances for it. Even a good rig
interface won't prevent it in certain antenna configurations (e.g.
portable ops, indoor antennas, unbalanced feedline with hot mikes in the
shack), so it's
--- In digitalradio@yahoogroups.com, John Bradley [EMAIL PROTECTED] w
I regularly use the rig's filters to enhance the signal quality at
my end. one thing I haven't got my head around yet are the noise
blankers and noise reduction devices, which seem to have an adverse
effect on the quality of
The efforts I am seeing might indicate that we are attempting to bite a
bit too large
On one side, the reports that Q15X25 works better at 2300 baud, and that
the 100 baud packet mode incorporated into MultiPSK works when 300 baud
does not looks like a hint to go at lower speeds and
John Becker wrote:
At 09:08 AM 1/9/2007, you wrote:
1. Power does not matter for digital modes.
This may hold true for sound card modes. Butt I think for the older
digital modes of RTTY AMTOR and PACTOR you will find that power does
matter.
Power matters for all of the digital modes.
mulveyraa2 wrote:
Are you using the mechanical filters, the DSP filters, or both?
Particularly for digital modes, the mechanical filters will make a
world of difference, since they'll be reducing the passband width - a
necessity in crowded conditions, or when a strong station is causing
Simon Brown wrote:
I don't think you should run these on the 480 as they are in the AF
chain and will always degrade the information you need to decode the
signal.
It's not what you hear, it's what your software can decode. Let the
software do the work...
Simon Brown, HB9DRV
I had
--- In digitalradio@yahoogroups.com, Roger J. Buffington
[EMAIL PROTECTED] wrote:
Simon Brown wrote:
I don't think you should run these on the 480 as they are in the AF
chain and will always degrade the information you need to decode the
signal.
It's not what you hear, it's what
mulveyraa2 wrote:
I had understood, perhaps incorrectly, that the TS480 provided for
mechanical filters, i.e. the excellent Kenwood 500 or 250 hz
filters.
The 480 does permit mechanical filters - two of them, in fact.
They're optional items though.
Actually, if you look at the
--- In digitalradio@yahoogroups.com, Roger J. Buffington
[EMAIL PROTECTED] wrote:
mulveyraa2 wrote:
Are you using the mechanical filters, the DSP filters, or both?
Particularly for digital modes, the mechanical filters will make a
world of difference, since they'll be reducing the
--- In digitalradio@yahoogroups.com, Danny Douglas [EMAIL PROTECTED] wrote:
The problem with running power in PSK mode, would mostly go away, if
one is careful about how much audio drive he is applying to the
signal. To ensure there are no side lobes on the waterfalls of other
ops, you much
Like you , I have both CW filters and use these regularly.. the NR function
at times seems to not work as well
although the rig is as close to perfect as you can get for both CW and digital
John
VE5MU
- Original Message -
From: mulveyraa2
To: digitalradio@yahoogroups.com
Hi Rick,
I built one, was horrid! Worked fine on the bench but not so good on
the air...went back to the KSR-33 with a TU using passive torroid
filters...back when you could get a jolt from an open TTY loop...had
a Nuvistor preamp too... state of the art (then)...fun times.
And yes, the
I believe the problem is that transceiver's used for digital service are still
designed, not for digital service, but for SSB and CW in which AGC is used:
1. To prevent blasting by strong signals when you are trying to hear weak
ones.
2. To protect the last IF amplifiers and detector from
- Original Message -
From: mulveyraa2 [EMAIL PROTECTED]
there are cases where the NR1 noise reducer
will help with signals on a noisy band.
As a summary of the responses, it seems than many use the TS-480SAT, I'll
probably be buying another for the 6m season so that I can monitor 6m
27 matches
Mail list logo
