Tom and all, T he signal you describe is indeed a JT65 signal and you
can either use JT65HF OR WSJT-X to decode it but might I submit that
the problem was with:
1 } Improperly adjusted sound card interface i.e. over driven and
drawing ALC (remember it is a digital signal)
2} A poorly operating SSB transceiver where the opposite sideband has
poor suppression. This type of transceiver will most likely QRM
someone even if on CW or SSB.
3.) He was running way way too much power. I never operate with more
than 30 watts {its a low power mode.. I worked VK5BC with 30w on TB
........try that with CW)
As a general rule all stations operating digital use USB now on all
bands but the program does not care which sideband you use the
transceiver sets that
Remember that the signal that enters the transceiver is digital and
as such will splatter if the signal input draws any appreciable ALC
I agree that if a particular signal was being heard on 33 he had a
problem of some type. If you find him again I would be willing to
make first contact ... I understand what signals should sound like
and look like on the display. I only suggest this because this mode
is kinda unique and uses (for the most part) canned messages.
Now to why digital is where it is in the band.. although we have been
here before....it is not by chance that digital is at that spot in
the band. They want to have QSOs with DX stations too and there are a
lot of countries that don't allow operation down the bottom of the
band but they do allow operation 1930-1950. Besides IF someone misses
these few KHz we have a major problem with the way we are operating.
Next I can and have operated CW directly among a whole wack of JT65
they didn,t know the difference and neither did I and if I can do it
with the TINITUS others can do it.
By the way operating digital is not about being an elite operator as
someone suggested in one of the local chat rooms, its about doing
something different and forging new ground.. or as James T. Kirk
called it .. "Going where no one has gone before"
Jim
Long Live Seal Team VI
http://www.qsl.net/wa3mej/index.htm ----- Original Message -----
From: topband-request@contesting.com To: topband@contesting.com Sent:
Wednesday, January 1, 2014 12:00:12 PM Subject: Topband Digest, Vol
133, Issue 1
Send Topband mailing list submissions to topband@contesting.com
To subscribe or unsubscribe via the World Wide Web, visit
http://lists.contesting.com/mailman/listinfo/topband or, via email,
send a message with subject or body 'help' to
topband-request@contesting.com
You can reach the person managing the list at
topband-owner@contesting.com
When replying, please edit your Subject line so it is more specific
than "Re: Contents of Topband digest..."
Today's Topics:
1. Re: Digial mode spurious issues (Mike Greenway) 2. Re: Digial mode
spurious issues (Joe Subich, W4TV) 3. Re: Digial mode spurious issues
(Mike Waters) 4. Re: Digital mode spurious issues (Tom W8JI)
----------------------------------------------------------------------
Message: 1 Date: Tue, 31 Dec 2013 17:10:27 -0500 From: "Mike
Greenway" <K4PI@BELLSOUTH.NET> To: <topband@contesting.com> Subject:
Re: Topband: Digial mode spurious issues Message-ID:
<52A7C61BC0414D61A4DD6EB286A01A81@SHACK> Content-Type: text/plain;
charset="utf-8"
I don?t am still puzzled why the digital modes decided to use the
1837 to 1839 area with the size of the 160 M band. I know the SSB
guys use a lot of the 1840-1900 area but 1900 to 2000 is usable isn?t
it? I rarely hear much up there and 3 or 4 khz up there would never
be missed. Probably not an answer but it has seemed strange to me
since they started operating in that area. Some of their signals are
bone crushing and wide. 73 Mike K4PI
From: topband-request@contesting.com Sent: Tuesday, December 31, 2013
12:00 PM To: topband@contesting.com Subject: Topband Digest, Vol 132,
Issue 30
Send Topband mailing list submissions to topband@contesting.com
To subscribe or unsubscribe via the World Wide Web, visit
http://lists.contesting.com/mailman/listinfo/topband or, via email,
send a message with subject or body 'help' to
topband-request@contesting.com
You can reach the person managing the list at
topband-owner@contesting.com
When replying, please edit your Subject line so it is more specific
than "Re: Contents of Topband digest..."
Today's Topics:
1. Digital mode spurious issues (Tom W8JI) 2. Re: Digital mode
spurious issues (Mike Waters) 3. Re: Digital mode spurious issues
(Jim Brown) 4. Re: Digital mode spurious issues (Richard (Rick)
Karlquist) 5. Re: Digital mode spurious issues (Joe Subich, W4TV) 6.
Re: Digital mode spurious issues (Charlie Cunningham) 7. Re: Digital
mode spurious issues (Jim Brown) 8. Re: [CQ-Contest] Stew Perry
Streaming Audio (Herb Schoenbohm) 9. Re: Digital mode spurious issues
(Grant Saviers) 10. Re: Digital mode spurious issues (W2RU - Bud
Hippisley) 11. Re: Digital mode spurious issues (Mike Waters) 12. Re:
Digital mode spurious issues (Charlie Cunningham) 13. Re: Digital
mode spurious issues (JC N4IS) 14. Re: Digital mode spurious issues
(Mike Waters) 15. Re: Digital mode spurious issues (Tom W8JI) 16. Re:
Digital mode spurious issues (Charlie Cunningham) 17. Re: Digital
mode spurious issues (Steven Raas) 18. Re: Digital mode spurious
issues (Mike Waters) 19. Re: Stew Perry Streaming Audio (Shoppa,
Tim) 20. CA/OR/AZ activity during Stew Perry - anecdotal data (Barry
N1EU) 21. Re: Digital mode spurious issues (Tom W8JI)
----------------------------------------------------------------------
Message: 1 Date: Mon, 30 Dec 2013 12:11:49 -0500 From: "Tom W8JI"
<w8ji@w8ji.com> To: "Topband" <topband@contesting.com> Subject:
Topband: Digital mode spurious issues Message-ID:
<AB0B5258E3B345428ADE0FAFD65179C0@MAIN> Content-Type: text/plain;
format=flowed; charset="iso-8859-1"; reply-type=response
I have not been on the air for a year or so, but decided to get back
on. I was listening to a DX station around 1833 when a digimode
station up roughly around 1837 came on with a LSB "spurious" signal
on 1833. His signal was a series of slowly changing stepped tones. I
don't know what mode that was. His unwanted sideband suppression was
about 40 dB, but that was not nearly enough. He was 15 dB out of
noise with his unwanted sideband.
Does anyone know of a universal software to decode signals? Since the
FCC does not require a CW ID, I think that is the only way to
identify stations.
I assume:
1.) Operators are unlikely to accept they have a problem if they are
getting good reports on the intentional signal
2.) Some rigs just should not be used for digimodes (this was a
sideband suppression issue)
3.) Those who unwisely placed digimode subbands next to popular weak
signal areas, especially when sideband selection produces a supurious
that falls in weak signal areas, are unlikely to rethink the poor
placement or poor advice on selecting sidebands
4.) With a little work to convince them, most digital ops with radio
problems would avoid operating
73 Tom
------------------------------
Message: 2 Date: Mon, 30 Dec 2013 12:30:34 -0600 From: Mike Waters
<mikewate@gmail.com> To: Tom W8JI <w8ji@w8ji.com> Cc: Topband
<topband@contesting.com> Subject: Re: Topband: Digital mode spurious
issues Message-ID:
<CA+FxYXj7jeqKdTtR1BWSWZU-ZjsC0h79YN8HhjDfJKs+xLzQPA@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Tom,
I believe the mode that operates at 1873-1838 is JT65, and WSJT is
needed to decode it. I never tried it. It was developed by K1JT for
weak-signal and EME work.
http://www.physics.princeton.edu/pulsar/K1JT/wsjt.html
A common scenario with digital modes is that the audio into the mic
input is too high, causing unwanted spurs.
73, Mike www.w0btu.com
On Mon, Dec 30, 2013 at 11:11 AM, Tom W8JI <w8ji@w8ji.com> wrote:
... a digimode station up roughly around 1837 came on with a LSB
"spurious" signal on 1833. His signal was a series of slowly
changing stepped tones. I don't know what mode that was. His
unwanted sideband suppression was about 40 dB, but that was not
nearly enough. He was 15 dB out of noise with his unwanted
sideband.
Does anyone know of a universal software to decode signals? Since
the FCC does not require a CW ID, I think that is the only way to
identify stations. ...
------------------------------
Message: 3 Date: Mon, 30 Dec 2013 14:17:57 -0800 From: Jim Brown
<jim@audiosystemsgroup.com> To: topband@contesting.com Subject: Re:
Topband: Digital mode spurious issues Message-ID:
<52C1F115.6050304@audiosystemsgroup.com> Content-Type: text/plain;
charset=ISO-8859-1; format=flowed
You're both right -- it is either JT65 or JT9. WSJT software, based
on protocols developed by K1JT, will decode both modes. Another
software package called JT65-HF will decode only JT65.
And yes, the trash Tom was hearing was either overdriven audio or a
crummy radio or both. Some of the newer hams using these modes are
also using pretty crummy radios -- all-banders in the $900 price
range. OTOH, most are running flea power -- 20W is QRO for this
crowd.
I've done a fair amount of JT65, mostly on 6M and 160M, using my K3.
I've also used other K1JT modes designed for meteor scatter (FSK441)
and ionospheric scatter (SCAT). JT9 is Joe's latest and greatest
protocol, requiring a fraction of the bandwidth of JT65.
73, Jim K9YC
On 12/30/2013 10:30 AM, Mike Waters wrote:
I believe the mode that operates at 1873-1838 is JT65, and WSJT is
needed to decode it. I never tried it. It was developed by K1JT for
weak-signal and EME work.
http://www.physics.princeton.edu/pulsar/K1JT/wsjt.html
A common scenario with digital modes is that the audio into the mic
input is too high, causing unwanted spurs.
------------------------------
Message: 4 Date: Mon, 30 Dec 2013 14:59:13 -0800 From: "Richard
(Rick) Karlquist" <richard@karlquist.com> To: topband@contesting.com
Subject: Re: Topband: Digital mode spurious issues Message-ID:
<52C1FAC1.2000809@karlquist.com> Content-Type: text/plain;
charset=ISO-8859-1; format=flowed
The simplest technical solution would be for the digital mode users
to put the radio in LSB mode. This puts unwanted sideband QRM away
from the DX CW window. Does the Joe Taylor software have a provision
for this?
Rick N6RK
------------------------------
Message: 5 Date: Mon, 30 Dec 2013 18:05:12 -0500 From: "Joe Subich,
W4TV" <lists@subich.com> To: topband@contesting.com Subject: Re:
Topband: Digital mode spurious issues Message-ID:
<52C1FC28.60806@subich.com> Content-Type: text/plain;
charset=ISO-8859-1; format=flowed
Does the Joe Taylor software have a provision for this?
No, Joe Taylor's protocols are not capable of operating in LSB.
73,
... Joe, W4TV
On 12/30/2013 5:59 PM, Richard (Rick) Karlquist wrote:
The simplest technical solution would be for the digital mode users
to put the radio in LSB mode. This puts unwanted sideband QRM away
from the DX CW window. Does the Joe Taylor software have a
provision for this?
Rick N6RK _________________ Topband Reflector Archives -
http://www.contesting.com/_topband
------------------------------
Message: 6 Date: Mon, 30 Dec 2013 18:13:47 -0500 From: "Charlie
Cunningham" <charlie-cunningham@nc.rr.com> To: "'Joe Subich, W4TV'"
<lists@subich.com>, <topband@contesting.com> Subject: Re: Topband:
Digital mode spurious issues Message-ID:
<!&!AAAAAAAAAAAYAAAAAAAAAF0xXac1rOhFkn7GlcEWNIjCgAAAEAAAABg31XzAMKNCvuYjy/t7uksBAAAAAA==@nc.rr.com>
Content-Type: text/plain; charset="us-ascii"
I would think that IMD products in a high-level PA that is
over-driven beyond good linearity limits could add some junk in the
"undesired sideband"? FWIW
Charlie, K4OTV
-----Original Message----- From: Topband
[mailto:topband-bounces@contesting.com] On Behalf Of Joe Subich,
W4TV Sent: Monday, December 30, 2013 6:05 PM To:
topband@contesting.com Subject: Re: Topband: Digital mode spurious
issues
Does the Joe Taylor software have a provision for this?
No, Joe Taylor's protocols are not capable of operating in LSB.
73,
... Joe, W4TV
On 12/30/2013 5:59 PM, Richard (Rick) Karlquist wrote:
The simplest technical solution would be for the digital mode users
to put the radio in LSB mode. This puts unwanted sideband QRM away
from the DX CW window. Does the Joe Taylor software have a
provision for this?
Rick N6RK _________________ Topband Reflector Archives -
http://www.contesting.com/_topband
_________________ Topband Reflector Archives -
http://www.contesting.com/_topband
------------------------------
Message: 7 Date: Mon, 30 Dec 2013 15:51:38 -0800 From: Jim Brown
<jim@audiosystemsgroup.com> To: topband@contesting.com Subject: Re:
Topband: Digital mode spurious issues Message-ID:
<52C2070A.40705@audiosystemsgroup.com> Content-Type: text/plain;
charset=ISO-8859-1; format=flowed
On 12/30/2013 3:13 PM, Charlie Cunningham wrote:
I would think that IMD products in a high-level PA that is
over-driven beyond good linearity limits could add some junk in the
"undesired sideband"? FWIW
Yes. Indeed, any IMD would do that. K6XX is an Elecraft engineer who
worked on their KPA500, among other things, and looked at a lot of
competing power amps in preparation for doing so. Bob recently did
an excellent tutorial presentation to a meeting of the Northern
California Contest Club about the root causes of sideband trash, the
general properties of various amplifier types, and how to minimize
the trash.
In general:
Distortion products increase when the antenna is poorly matched to
the amplifier That's true whether it's a tuned tube amp or a fixed
tuned solid state amp -- in other words, the tube amp must be
carefully tuned, and the solid state amp should be used with a tuner
if the antenna is not an ideal match.
Distortion products increase as power supply voltage decreases. In
other words, a rig designed to run on 13.8 volts will be much cleaner
at 13.8 volts than at 12V.
Most solid state output stages are cleaner at half power than at
full power. That means that a rig will be cleaner driving a power amp
at 50W than at 100 W.
Using AGC between the power amp and the rig to set output level is a
recipe for sideband trash.
A properly tuned hollow state power amp is typically 8-10 dB cleaner
than the best solid state amps.
Fast rise time of the keying waveform is the major cause of clicks
W8JI and others long ago identified this as the cause of the
FT1000-series rigs awful clicks, and fixed them. The rise time of
some rigs (notably the IC7600) is adjustable, and only the slowest
rise time is acceptable. The K3 uses an optimally shaped keying
waveform (which designer N6KR calls "sigmoidal") to minimize clicks,
and it is not user adjustable.
Most ICOM rigs have overshoot that also causes clicks.
Something I learned from N6KR a few days ago is that the very low
level of sideband trash from a K3 is the result of two design
elements. First, the synthesizer is very clean.. Second, they run it
through the TX crystal filter, which gets rid of trash more distant
from the carrier.
73, Jim K9YC
------------------------------
Message: 8 Date: Mon, 30 Dec 2013 20:39:45 -0400 From: Herb
Schoenbohm <herbs@vitelcom.net> To: topband@contesting.com Subject:
Re: Topband: [CQ-Contest] Stew Perry Streaming Audio Message-ID:
<52C21251.6010200@vitelcom.net> Content-Type: text/plain;
charset=ISO-8859-1; format=flowed
This is just not possible anymore and there are so many situations
like Greg experiences where the only hope to hear anything is by
employing new technology. Also the 100KM rule, if there is such a
rule, is intriguing because a remote RX in the BVI (a different DXCC
country) would really be nice now that I have a new ham a few blocks
away running a CQ machine during the contest in the DX window for the
duration of the contest. Problems such as this along with high urban
QRN are much more common and solution will be found. To arbitrarily
block new innovations and technology to solve some of these issues is
to me not going in the right direction. I think a better approach
would be to allow for different categories creating incentives for
inovations, rather than just outright ban them.
Herb Schoenbohm, KV4FZ
On 12/28/2013 4:19 PM, Greg - ZL3IX wrote:
"enjoy the contest the way we did back when Stew Perry was around"
------------------------------
Message: 9 Date: Mon, 30 Dec 2013 17:12:10 -0800 From: Grant Saviers
<grants2@pacbell.net> To: Tom W8JI <w8ji@w8ji.com>, Topband
<topband@contesting.com> Subject: Re: Topband: Digital mode spurious
issues Message-ID: <52C219EA.6040106@pacbell.net> Content-Type:
text/plain; charset=ISO-8859-1; format=flowed
The SignaLink supported software page has a nice summary of software
decoders see http://www.tigertronics.com/sl_soft.htm
If "universal" means automatic selection of the correct decoding
mode, that would be a challenge!
Grant KZ1W
On 12/30/2013 9:11 AM, Tom W8JI wrote:
I have not been on the air for a year or so, but decided to get
back on. I was listening to a DX station around 1833 when a
digimode station up roughly around 1837 came on with a LSB
"spurious" signal on 1833. His signal was a series of slowly
changing stepped tones. I don't know what mode that was. His
unwanted sideband suppression was about 40 dB, but that was not
nearly enough. He was 15 dB out of noise with his unwanted
sideband.
Does anyone know of a universal software to decode signals? Since
the FCC does not require a CW ID, I think that is the only way to
identify stations.
I assume:
1.) Operators are unlikely to accept they have a problem if they
are getting good reports on the intentional signal
2.) Some rigs just should not be used for digimodes (this was a
sideband suppression issue)
3.) Those who unwisely placed digimode subbands next to popular
weak signal areas, especially when sideband selection produces a
supurious that falls in weak signal areas, are unlikely to rethink
the poor placement or poor advice on selecting sidebands
4.) With a little work to convince them, most digital ops with
radio problems would avoid operating
73 Tom _________________ Topband Reflector Archives -
http://www.contesting.com/_topband
------------------------------
Message: 10 Date: Mon, 30 Dec 2013 20:32:37 -0500 From: W2RU - Bud
Hippisley <W2RU@frontiernet.net> To: jim@audiosystemsgroup.com Cc:
topband@contesting.com Subject: Re: Topband: Digital mode spurious
issues Message-ID:
<656317B8-1858-42F1-9FFD-23DDE17534A6@frontiernet.net> Content-Type:
text/plain; charset=us-ascii
This is a little off-topic relative to the Subject line, but
extremely relevant to enjoyable Topband operating:
On Dec 30, 2013, at 6:51 38PM, Jim Brown <jim@audiosystemsgroup.com>
wrote:
Fast rise time of the keying waveform is the major cause of clicks.
W8JI and others long ago identified this as the cause of the
FT1000-series rigs awful clicks, and fixed them. The rise time of
some rigs (notably the IC7600) is adjustable, and only the slowest
rise time is acceptable.
Add the venerable Kenwood TS-950SDX to the list of rigs with
user-adjustable rise/fall times. And -- as Jim notes -- only the
slowest rise time is fully acceptable, despite the pains Kenwood took
to carefully "shape" those RF waveforms during their "on" and "off"
transition periods.
In the case of the 950SDX, the user can select nominal rise/fall
times labeled 2, 4, 6, or 8 milliseconds (ms) from one of the
configuration menus accessible via the front panel MENU options. A
few years back, in extensive tests on a daytime 80-m band with an
equally fanatical friend listening critically, we determined that
-only- the 8-ms setting was "clean" with respect to click generation.
Probably the 6-ms setting would be marginally "OK" if the transmitted
signal were not loud anywhere, but since my usual objective when
chasing DX on 160 is to be as loud as I can, 6 ms is not really an
acceptable solution for maintaining good relations with my close-in
Topband "neighbors" here on the east coast of North America. Once we
ran those tests, I set the TS-950SDX menu choice to 8 ms, and I've
not changed it since.
Bud, W2RU
------------------------------
Message: 11 Date: Mon, 30 Dec 2013 20:12:33 -0600 From: Mike Waters
<mikewate@gmail.com> To: topband <topband@contesting.com> Subject:
Re: Topband: Digital mode spurious issues Message-ID:
<CA+FxYXiRKZnGLMKGdN1aTsFzBFkrGdY03znWG59EtadKSmF+jQ@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
You are right. There is no universal software that can do that. But I
used to code software, and I'm convinced that the status quo in
amateur digital software can be greatly improved. See
http://www.eham.net/ehamforum/smf/index.php?topic=80740.0 .
If anyone wants to take up where we left off on that eHam thread,
then let's take the discussion there.
73, Mike www.w0btu.com
On Mon, Dec 30, 2013 at 7:12 PM, Grant Saviers <grants2@pacbell.net>
wrote:
If "universal" means automatic selection of the correct decoding
mode, that would be a challenge!
------------------------------
Message: 12 Date: Mon, 30 Dec 2013 21:34:26 -0500 From: "Charlie
Cunningham" <charlie-cunningham@nc.rr.com> To:
<jim@audiosystemsgroup.com>, <topband@contesting.com> Subject: Re:
Topband: Digital mode spurious issues Message-ID:
<!&!AAAAAAAAAAAYAAAAAAAAAF0xXac1rOhFkn7GlcEWNIjCgAAAEAAAAJjC6JAJz/RMjAuEvO+ytjsBAAAAAA==@nc.rr.com>
Content-Type: text/plain; charset="us-ascii"
Hi, Jim
Well as one who has been an RF and radio engineer and designer for
40+ years, I have to agree with most all of your points. Great deal
of truth in there, but so many guys don't appreciate all those things
and their inclination is "crank it to the right" and "the "louder you
shout, the further you get"! And they are looking for large meter
excursions. To appreciate the tendency to overdrive transmitters and
amplifiers. One need only listen to the the prevalence of awful key
clicks and SSB splatter in contests!
(And "real men" use vacuum tubes to develop "real power"! :-) )
73, Charie, K4OTV
-----Original Message----- From: Topband
[mailto:topband-bounces@contesting.com] On Behalf Of Jim Brown Sent:
Monday, December 30, 2013 6:52 PM To: topband@contesting.com Subject:
Re: Topband: Digital mode spurious issues
On 12/30/2013 3:13 PM, Charlie Cunningham wrote:
I would think that IMD products in a high-level PA that is
over-driven beyond good linearity limits could add some junk in the
"undesired sideband"? FWIW
Yes. Indeed, any IMD would do that. K6XX is an Elecraft engineer who
worked on their KPA500, among other things, and looked at a lot of
competing power amps in preparation for doing so. Bob recently did
an excellent tutorial presentation to a meeting of the Northern
California Contest Club about the root causes of sideband trash, the
general properties of various amplifier types, and how to minimize
the trash.
In general:
Distortion products increase when the antenna is poorly matched to
the amplifier That's true whether it's a tuned tube amp or a fixed
tuned solid state amp -- in other words, the tube amp must be
carefully tuned, and the solid state amp should be used with a tuner
if the antenna is not an ideal match.
Distortion products increase as power supply voltage decreases. In
other words, a rig designed to run on 13.8 volts will be much cleaner
at 13.8 volts than at 12V.
Most solid state output stages are cleaner at half power than at
full power. That means that a rig will be cleaner driving a power amp
at 50W than at 100 W.
Using AGC between the power amp and the rig to set output level is a
recipe for sideband trash.
A properly tuned hollow state power amp is typically 8-10 dB cleaner
than the best solid state amps.
Fast rise time of the keying waveform is the major cause of clicks
W8JI and others long ago identified this as the cause of the
FT1000-series rigs awful clicks, and fixed them. The rise time of
some rigs (notably the IC7600) is adjustable, and only the slowest
rise time is acceptable. The K3 uses an optimally shaped keying
waveform (which designer N6KR calls "sigmoidal") to minimize clicks,
and it is not user adjustable.
Most ICOM rigs have overshoot that also causes clicks.
Something I learned from N6KR a few days ago is that the very low
level of sideband trash from a K3 is the result of two design
elements. First, the synthesizer is very clean.. Second, they run it
through the TX crystal filter, which gets rid of trash more distant
from the carrier.
73, Jim K9YC _________________ Topband Reflector Archives -
http://www.contesting.com/_topband
------------------------------
Message: 13 Date: Mon, 30 Dec 2013 21:50:47 -0500 From: "JC N4IS"
<n4is@comcast.net> To: "'Mike Waters'" <mikewate@gmail.com>, "'Tom
W8JI'" <w8ji@w8ji.com> Cc: 'Topband' <topband@contesting.com>
Subject: Re: Topband: Digital mode spurious issues Message-ID:
<005801cf05d3$1bd5f9c0$5381ed40$@comcast.net> Content-Type:
text/plain; charset="us-ascii"
Tom, Mike is right, the issue with audio overload is complex for most
of new radios, most of them have A/D just at the MIC input, if the
A/D overloads the RF chain is compromised. These radios have no
actual filters, everything is digital, like the IC7600. An analog
radio is BW limited by the SSB crystal filter but SDR don't, when the
A/D overloads, there are spoors everywhere several KHz far from the
carrier; enough to trash the entire band.
Using a SDR water fall it is easy to see the signal transitions and
associate the trash with the main signal. I've seen several spoors
every 10 KHz almost 100KHz up and down 1838. This is a growing
problem.
73, JC N4IS
-----Original Message----- From: Topband
[mailto:topband-bounces@contesting.com] On Behalf Of Mike Waters
Sent: Monday, December 30, 2013 1:31 PM To: Tom W8JI Cc: Topband
Subject: Re: Topband: Digital mode spurious issues
Tom,
I believe the mode that operates at 1873-1838 is JT65, and WSJT is
needed to decode it. I never tried it. It was developed by K1JT for
weak-signal and EME work.
http://www.physics.princeton.edu/pulsar/K1JT/wsjt.html
A common scenario with digital modes is that the audio into the mic
input is too high, causing unwanted spurs.
73, Mike www.w0btu.com
On Mon, Dec 30, 2013 at 11:11 AM, Tom W8JI <w8ji@w8ji.com> wrote:
... a digimode station up roughly around 1837 came on with a LSB
"spurious" signal on 1833. His signal was a series of slowly
changing stepped tones. I don't know what mode that was. His
unwanted sideband suppression was about 40 dB, but that was not
nearly enough. He was 15 dB out of noise with his unwanted
sideband.
Does anyone know of a universal software to decode signals? Since
the FCC does not require a CW ID, I think that is the only way to
identify stations. ...
_________________ Topband Reflector Archives -
http://www.contesting.com/_topband
------------------------------
Message: 14 Date: Mon, 30 Dec 2013 21:17:28 -0600 From: Mike Waters
<mikewate@gmail.com> To: topband <topband@contesting.com> Subject:
Re: Topband: Digital mode spurious issues Message-ID:
<CA+FxYXikYNQqzEAf+rHdJkNG1ztop1_V3UbBiTauLsRzpMqQ_g@mail.gmail.com>
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Bingo! The waterfall display was a wonderful invention, wasn't it?
And I don't even use SDR. (Yet.)
When I used to operate PSK31, I adjusted the audio levels with my
own signal displayed on the waterfall, and so it was easy to see when
the input from the sound card was too high. The spurs from AF
overload are very easy to see on the waterfall.
73, Mike www.w0btu.com
On Mon, Dec 30, 2013 at 8:50 PM, JC N4IS <n4is@comcast.net> wrote:
Using a SDR water fall it is easy to see the signal transitions
and associate the trash with the main signal. I've seen several
spoors every 10 KHz almost 100KHz up and down 1838. This is a
growing problem.
------------------------------
Message: 15 Date: Mon, 30 Dec 2013 22:55:46 -0500 From: "Tom W8JI"
<w8ji@w8ji.com> To: <topband@contesting.com> Subject: Re: Topband:
Digital mode spurious issues Message-ID:
<11A6F15D3D9F452F83930E7A3EBDA10F@MAIN> Content-Type: text/plain;
format=flowed; charset="iso-8859-1"; reply-type=original
Thanks everyone for the suggestions. I'm going to have to install
some software to identify some of the signals.
I would think that IMD products in a high-level PA that is
over-driven beyond good linearity limits could add some junk in the
"undesired sideband"? FWIW
IMD **requires** two or more signals at once, and does not appear
anything like sideband leakage. This was a single shifting tone, and
the lower frequency signal went the opposite way but the same amount
as the main signal with shifts. That is classic for inadequate
sideband suppression.
There are multiple problems with using SSB to transmit audio tones
and "thinking" it is a pure digi mode.
1.) things like this do not show on almost all digi waterfalls
because they are out of passband of the other fellows receiver.
2.) SSB carrier, noise, and opposite sideband suppression is limited
by the radio quality
3.) output purity is also limited by audio input purity, which
includes audio line issues
4.) most digi operators do not have the low noise antennas most DXers
have, and cannot hear some fairly strong signals. They are often on
digimodes because of that!
5.) radios have terrible SSB transmitter performance compared to even
fair receivers, so the transmitters often set the adjacent channel
interference levels
Placing digimodes near weak signal areas is not very wise frequency
planning, but there is nothing anyone can do about it.
------------------------------
Message: 16 Date: Mon, 30 Dec 2013 23:28:41 -0500 From: "Charlie
Cunningham" <charlie-cunningham@nc.rr.com> To: "'Tom W8JI'"
<w8ji@w8ji.com>, <topband@contesting.com> Subject: Re: Topband:
Digital mode spurious issues Message-ID:
<!&!AAAAAAAAAAAYAAAAAAAAAF0xXac1rOhFkn7GlcEWNIjCgAAAEAAAABORbRe1dtFDk174Pca2TsABAAAAAA==@nc.rr.com>
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Well, I certainly have to agree, Tom, if the signal on the desired
sideband is just a single shifting tone. Might get messier if an
sudio stage or A/D is driven into limiting and producing harmonic
distortion at audio, I guess.
73, Charlie, K4OTV
-----Original Message----- From: Topband
[mailto:topband-bounces@contesting.com] On Behalf Of Tom W8JI Sent:
Monday, December 30, 2013 10:56 PM To: topband@contesting.com
Subject: Re: Topband: Digital mode spurious issues
Thanks everyone for the suggestions. I'm going to have to install
some software to identify some of the signals.
I would think that IMD products in a high-level PA that is
over-driven beyond good linearity limits could add some junk in the
"undesired sideband"? FWIW
IMD **requires** two or more signals at once, and does not appear
anything like sideband leakage. This was a single shifting tone, and
the lower frequency signal went the opposite way but the same amount
as the main signal with shifts. That is classic for inadequate
sideband suppression.
There are multiple problems with using SSB to transmit audio tones
and "thinking" it is a pure digi mode.
1.) things like this do not show on almost all digi waterfalls
because they are out of passband of the other fellows receiver.
2.) SSB carrier, noise, and opposite sideband suppression is limited
by the radio quality
3.) output purity is also limited by audio input purity, which
includes audio line issues
4.) most digi operators do not have the low noise antennas most DXers
have, and cannot hear some fairly strong signals. They are often on
digimodes because of that!
5.) radios have terrible SSB transmitter performance compared to even
fair receivers, so the transmitters often set the adjacent channel
interference levels
Placing digimodes near weak signal areas is not very wise frequency
planning, but there is nothing anyone can do about it.
_________________ Topband Reflector Archives -
http://www.contesting.com/_topband
------------------------------
Message: 17 Date: Mon, 30 Dec 2013 23:29:09 -0500 From: Steven Raas
<sjraas@gmail.com> To: Tom W8JI <w8ji@w8ji.com> Cc:
"topband@contesting.com" <topband@contesting.com> Subject: Re:
Topband: Digital mode spurious issues Message-ID:
<CABOEzZoFoWUPJ9zD3b4t1yDjwjLaBKui8dnU1L+1eYB=0woMYw@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Tom,
I would have to agree. Let me also add my personal experiences on
160m JT65, were good, however, at the latter stages of me being QRV
on the band, I was very politely spoken to, and delightfully educated
on such matters by Les, KL7J , whom really gave me some great insight
on a then and still new band to me, for this I am ever grateful. We
tried to contact on many occasions a few years back on 160M JT-65,
however the latter attempts were lower in the band , 1807 ish or so
if I recall. I was one of the many daily 160M ops for quite some
time, but after learning, & progressing, if I was QRV on 160 at the
moment, I would take it ( digital ops ) down the band. I will also
admit, that I was lured with the possibility ( at those times ) of my
1st trans-oceanic 160m QSO using JT65 ( or any mode ) , with my
experiences now, I would say that waiting for prop, and running 4 or
5 cw q's was much easier for those 1st trans-oceanic q's. Not to
mention that the long deep fades that I had ( with very very limited
antennas which are frequently common with 160 digi mode ops ) would
not be very beneficial for JT65 ' long haul / high qsb qso's, however
this is not always the case. I can even say that to this day, I had
yet to work any DX on 160m JT-65, cw now, is a different story
thankfully :) There is also WSPR activity in that area of the band if
I recall ( that may have changed ) amongst a few others. I think that
progress could be made in getting the digi ops to qsy, perhaps to the
lower end of the band, I'll be honest tho, I think that the hardest
part would be getting the word out to the masses, however when
presented with facts, and honest concern with the forsight of keeping
the band active and everyone happy, my guess is that few would
gripe.. but the masses just want to make qso's like the rest of us,
and would in time oblige. I digress..have a great new year everyone &
enjoy !
-Steve Raas N2JDQ
On Mon, Dec 30, 2013 at 10:55 PM, Tom W8JI <w8ji@w8ji.com> wrote:
Thanks everyone for the suggestions. I'm going to have to install
some software to identify some of the signals.
I would think that IMD products in a high-level PA that is
over-driven
beyond good linearity limits could add some junk in the
"undesired sideband"? FWIW
IMD **requires** two or more signals at once, and does not appear
anything like sideband leakage. This was a single shifting tone,
and the lower frequency signal went the opposite way but the same
amount as the main signal with shifts. That is classic for
inadequate sideband suppression.
There are multiple problems with using SSB to transmit audio tones
and "thinking" it is a pure digi mode.
1.) things like this do not show on almost all digi waterfalls
because they are out of passband of the other fellows receiver.
2.) SSB carrier, noise, and opposite sideband suppression is
limited by the radio quality
3.) output purity is also limited by audio input purity, which
includes audio line issues
4.) most digi operators do not have the low noise antennas most
DXers have, and cannot hear some fairly strong signals. They are
often on digimodes because of that!
5.) radios have terrible SSB transmitter performance compared to
even fair receivers, so the transmitters often set the adjacent
channel interference levels
Placing digimodes near weak signal areas is not very wise
frequency planning, but there is nothing anyone can do about it.
_________________ Topband Reflector Archives -
http://www.contesting.com/_topband
------------------------------
Message: 18 Date: Mon, 30 Dec 2013 22:48:18 -0600 From: Mike Waters
<mikewate@gmail.com> To: topband <topband@contesting.com> Subject:
Re: Topband: Digital mode spurious issues Message-ID:
<CA+FxYXjOemiJtEBo+HJsWjeeNBZvc8YVEwx8tgEQhoCJ-8Mfcg@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Maybe not.
I got a private e-mail earlier (which I haven't had time to respond
to yet) that stated "To see who is QRV on 160M WSPR at any given
time, check at http://wsprnet.org/drupal/wsprnet/activity Scroll down
to 160M and the stations are listed (those followed by an R are just
receiving)."
73, Mike www.w0btu.com
On Mon, Dec 30, 2013 at 9:55 PM, Tom W8JI <w8ji@w8ji.com> wrote:
Thanks everyone for the suggestions. I'm going to have to install
some software to identify some of the signals.
------------------------------
Message: 19 Date: Tue, 31 Dec 2013 13:49:06 +0000 From: "Shoppa, Tim"
<tshoppa@wmata.com> Cc: "topband@contesting.com"
<topband@contesting.com> Subject: Re: Topband: Stew Perry Streaming
Audio Message-ID:
<303A17BD5F8FA34DA45EEC245271AC0B949D647F@JGEX2K10MBX2.wmata.local>
Content-Type: text/plain; charset="us-ascii"
I always set these software-based goals before the test, but funny
how they get delayed in the face of driving kids around to
acitivities and stringing up antennas in the trees, and then when the
sun goes down and the contest starts swinging, all those pie in the
sky virtual dreams evaporate in the face of real QSO's to be made
:-)
I had a lot of fun in the Stew Perry and felt my new west-facing
pennant was an improvement for stations in the deeper west and on
west coast. I'm sure I didn't hear some low power California stations
that tried to call me.
Tim N3QE ________________________________________ From: Shoppa, Tim
Sent: Saturday, December 28, 2013 9:58 AM Cc: topband@contesting.com
Subject: RE: Topband: Stew Perry Streaming Audio
Streaming audio live during the contest doesn't seem particularly
useful to me.
But recordings made available post-contest over the web, those might
be interesting to others. I'm going to see if I can set that up at my
(much more modest) shack. I would love to hear what my signal sounds
like on West Coast or in EU.
Tim N3QE
________________________________________ From: Topband
[topband-bounces@contesting.com] on behalf of Tree [tree@kkn.net]
Sent: Saturday, December 28, 2013 9:39 AM To: Eric NO3M Cc: Stan
Stockton; topband@contesting.com; cq-contest@contesting.com; Clive
GM3POI Subject: Re: Topband: Stew Perry Streaming Audio
Perhaps a different approach is to make it available to people who
are interested in hearing it. There are probably some people who are
not able to operate the contest and would appreciate the opportunity
to hear what it sounds like. Also - Eric is a top notch operator and
being able to listen to how he uses two radios might be educational
for some.
I really doubt there is going to be abuse of this - despite what our
imaginations come up with. I know K5ZD and others have done this for
other major contests.
Tree N6TR
On Sat, Dec 28, 2013 at 3:39 AM, Eric NO3M <no3m@no3m.net> wrote:
Since there seems to be too much concern over this, though no ill
intent was intended, audio will not be broadcast.
GL / 73 Eric NO3M
On 12/28/2013 06:23 AM, Stan Stockton wrote:
Eric,
You made it clear what you were doing, and I am quite sure Clive
understood. I think the logic behind his question has to do with
whether it is within the spirit of the contest - especially this
one. Let's say, as a result of the announcement or advertisement
, 15 DX stations and 25 USA stations who are not even going to
send in their log called you, just for fun and the novelty of it,
so they could listen to their own signal at your end via
Internet.
What if some have enough QRM or QRN that they could only copy
whether you came back to them by listening via internet? Fair to
your competitors?
It is cool, but I've always had a problem with this, regardless
of what contest.
73...Stan, K5GO
Sent from my iPad
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------------------------------
Message: 20 Date: Tue, 31 Dec 2013 09:21:38 -0500 From: Barry N1EU
<barry.n1eu@gmail.com> To: topBand List <topband@contesting.com>
Subject: Topband: CA/OR/AZ activity during Stew Perry - anecdotal
data Message-ID:
<CAFmfzDsZyK07vxthFnRs141HN_9Q6uo8HpGSOQfHAUaO86pGmw@mail.gmail.com>
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I thought I'd share some data points from my Stew Perry log. Even
though propagation to the west coast seemed good from upstate NY, I
had the impression of less activity than expected from California so
I looked closer at my log. What I found was 13 q's from California
and 14 q's each from neighboring Oregon and Arizona (each with 1/7 of
the ham population of CA). Perhaps the ham population in California
is disproportionately urban/suburban with less topband activity,
Californians disproportionately go QRP in SP or ???
73 & Happy New Year, Barry N1EU
------------------------------
Message: 21 Date: Tue, 31 Dec 2013 10:13:29 -0500 From: "Tom W8JI"
<w8ji@w8ji.com> To: "Charlie Cunningham"
<charlie-cunningham@nc.rr.com>, <topband@contesting.com> Subject: Re:
Topband: Digital mode spurious issues Message-ID:
<952FFD43F713459C9780E88B677DE50E@MAIN> Content-Type: text/plain;
format=flowed; charset="iso-8859-1"; reply-type=original
Well, I certainly have to agree, Tom, if the signal on the desired
sideband is just a single shifting tone. Might get messier if an
sudio stage or A/D is driven into limiting and producing harmonic
distortion at audio, I guess.
The entire thing for digital modes was poorly planned. I'm surprised
no one objected to the frequency choices (of Europe), because they
are technically always going to be a long term problem. The frequency
range really could not have been more poorly planned for future
long-term band use.
Any digital mode piped into the SSB transmitter system, like it or
not, is really SSB modulated. It has all the noise, carrier, and
opposite sideband suppression issues, as well as sensitivity to
levels. If they transmit 1835-40 using USB on the radio, the opposite
sideband falls in the 1832 and upward range. IMD can be anywhere, if
it is a multiple tone at the same time mode. Harmonic distortion is
upward from the carrier on USB.
Collins got burned by this. They tried running a pure audio tone into
the SSB transmitter of the early S line to generate CW. The FCC (back
when they did enforcement) starting handing out pink slips left and
right to Collins owners. Any carrier, noise, or harmonic distortion
at all resulted in an FCC citation, so Collins had to convert
transmitters back to a keyed carrier.
Anything converted to RF in a SSB transmitter system really belongs
off by itself, well away from other operation. It's really a
technical issue that will always exist, because the basic RF
generation system or idea is flawed.
------------------------------
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------------------------------
Message: 2 Date: Tue, 31 Dec 2013 17:51:52 -0500 From: "Joe Subich,
W4TV" <lists@subich.com> To: topband@contesting.com Subject: Re:
Topband: Digial mode spurious issues Message-ID:
<52C34A88.3010206@subich.com> Content-Type: text/plain;
charset=windows-1252; format=flowed
On 12/31/2013 5:10 PM, Mike Greenway wrote:
I don?t am still puzzled why the digital modes decided to use the
1837to 1839 area with the size of the 160 M band.
For the same reason the SSB guys insist on using 1840-1850 ... with
their significantly smaller band (1810-1850 in some cases) Region 1
put digital between CW (1810-1830) and SSB (1840-1850). With what is
left of the "DX Window" at 1830-1835 that left 1835-1840 for
digital.
It's an unavoidable fact of life that new activity will go where the
existing activity is. Look at digital on 40 meters - it is almost all
between 7030/7035 and 7045 because that's where the EU and JA
stations are. 160 is no different, digital activity in EU is
1835-1840 so that's where everyone else will be if they want a chance
to work EU. As much as it pains me to say it - if you want to fix the
situation get ITU to expand the 160 meter band in Region 1 and
convince IARU Region 1 to relocate both digital and SSB activity
higher/into the expanded band.
73,
... Joe, W4TV
On 12/31/2013 5:10 PM, Mike Greenway wrote:
I don?t am still puzzled why the digital modes decided to use the
1837to 1839 area with the size of the 160 M band. I know the SSB
guys use a
lot of the 1840-1900 area but 1900 to 2000 is usable isn?t it? I
rarely hear much up there and 3 or 4 khz up there would never be
missed. Probably not an answer but it has seemed strange to me since
they started operating in that area. Some of their signals are bone
crushing and wide. 73 Mike K4PI
------------------------------
Message: 3 Date: Tue, 31 Dec 2013 17:29:57 -0600 From: Mike Waters
<mikewate@gmail.com> To: Mike Greenway <K4PI@bellsouth.net>, topband
<topband@contesting.com> Subject: Re: Topband: Digial mode spurious
issues Message-ID:
<CA+FxYXimxpes9qB+SafJF2JdnM1fAvtrFd0NuBKOOg3ohw9Nbg@mail.gmail.com>
Content-Type: text/plain; charset=windows-1252
Absolutely! From what I see from my QTH in SW MO, 1845 would be a
good place for JT65 to move to. There is a ragchew group that meets
on 1850, but seldom is there much activity below that.
I seldom listen much above 1900. Maybe you're right, that would be a
better place. But they definitely need to move up, as there's often
DX just below them and we are just not going to get everyone to
transmit a clean digital signal.
By the way, Mike, it's easy to trim the large amount of text off the
end of your messages with Shift-Ctrl-End and then Delete. :-) I've
noticed others here forgetting to do that lately, too.
73, Mike www.w0btu.com
On Tue, Dec 31, 2013 at 4:10 PM, Mike Greenway <K4PI@bellsouth.net>
wrote:
I don?t am still puzzled why the digital modes decided to use the
1837 to 1839 area with the size of the 160 M band. I know the SSB
guys use a lot of the 1840-1900 area but 1900 to 2000 is usable
isn?t it? I rarely hear much up there and 3 or 4 khz up there would
never be missed. Probably not an answer but it has seemed strange
to me since they started operating in that area. Some of their
signals are bone crushing and wide. 73 Mike K4PI
------------------------------
Message: 4 Date: Tue, 31 Dec 2013 19:14:13 -0500 From: "Tom W8JI"
<w8ji@w8ji.com> To: <topband@contesting.com> Subject: Re: Topband:
Digital mode spurious issues Message-ID:
<18EE60A52F2A4E9182529136341FE673@MAIN> Content-Type: text/plain;
format=flowed; charset="iso-8859-1"; reply-type=response
AFAIK, all non-DSP rigs with synthesizers work this way. Assuming
you want the output frequency to be derived from the master clock
frequency, there is no easy way to shift an RF carrier. You can't
use a free running oscillator, because it won't be derived from the
master clock frequency. You can't switch between a mark synthesizer
and a space synthesizer because of transients. If you try to key
the programmed frequency of a BFO synthesizer, the PLL will
probably go out of lock momentarily, producing garbage. Also, it
may not be fast enough to keep up with RTTY. After considering all
this (as a very experienced synthesizer designer) it is hard for me
to blame the designers for using AFSK.
It is easy to do it much better, and it would only cost pennies extra
at the most. The signal could be generated by the normal SSB system
and then run through a narrow IF filter. Problem solved. They could
have done CW the same way, or in a similar fashion, with an unshaped
off-on carrier through a narrow filter. They just didn't think to use
the parts they already had in the radio.
But that isn't this issue. This issue is they run baseband audio from
a computer into a SSB transmitter to generate TX signals. This means
it is really a SSB transmitter processing the tones, and they don't
even restrict bandwidth with a narrow filter. That is really the
entire issue. Instead of a narrow filter cleaning up stuff, it all
goes through a SSB filter. Anyone with a computer and a little skill
can invent a "new mode". It's just bad engineering to stick that
stuff near weak signals, because the problem can only be fixed at the
transmitter.
73 Tom
------------------------------
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