[RTTY] K3 RTTY bandwidth already too narrow?
RLVZ at aol.com
RLVZ at aol.com
Sat Mar 23 16:15:17 EDT 2013
I understand the desirable effects of reducing bandwidth... but sometimes
I wonder if the K3's transmit bandwidth on RTTY is already too narrow.
Case in point: I enjoy operating a lot of RTTY contests, but even when I'm
running 1,500 watts... I continually have stations that move in real close to
me and cause me a tremendous amount of received interference. (I often
have to QSY which is frustrating when I've got a nice run taking place) And
that's when I'm running my receive filters tight, such as: 250hz roofing
filter with DSP filter set at 350hz. (though I prefer to use my 400hz
roofing filter with a 400hz DSP setting as it copies signals better) So it seems
to me that: 1) either their receiver selectivity is better then that of my
K3... which is unlikely, or 2) my K3 is already transmitting a much cleaner
signal then theirs. If my K3 transmit signal is already much cleaner then
theirs, then I'm going to receive even greater QRM if I narrow my K3
transmit bandwidth further. Which is why I sometimes wonder if my K3 transmit b
andwidth isn't already too narrow. Again, I appreciate the effort to
reduce bandwidth as it's a good thing, but more effort needs to be made for this
to happen on a global scale.
I like the idea of stations with BIG bandwidths and Key Clixs to be
penalized or disqualified. But that's unlikely to happen with any regularity.
73,
Dick- K9OM
In a message dated 3/23/2013 12:01:41 P.M. Eastern Daylight Time,
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Today's Topics:
1. Re: K3 reduced-bandwidth RTTY analysis (Jay WS7I)
2. Re: K3 reduced-bandwidth RTTY analysis (Kok Chen)
3. Re: K3 reduced-bandwidth RTTY analysis (Robert Chudek - K0RC)
4. Re: K3 reduced-bandwidth RTTY analysis (Lee Roberts)
5. My thoughts on RTTY analysis (Phil Sussman)
6. Re: My thoughts on RTTY analysis (Bill Turner)
7. Re: K3 reduced-bandwidth RTTY analysis (Jim W7RY)
8. First RTTY QRP Contest (Walter Dallmeier)
9. Re: First RTTY QRP Contest (Elmar PD3EM)
----------------------------------------------------------------------
Message: 1
Date: Fri, 22 Mar 2013 14:25:20 -0700
From: Jay WS7I <ws7ik7tj at gmail.com>
To: W8AEF <w8aef at q.com>
Cc: rtty at contesting.com
Subject: Re: [RTTY] K3 reduced-bandwidth RTTY analysis
Message-ID: <514CCC40.8020908 at gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Yeah but they don't mix the processor with it nor does the Mic Gain
usually have a lot of difference, which is of course why they do it that
way and why most of us contest guys and gals use FSK not that it is
better but its easier. They also don't shape the FSK or AFSK if you
would rather either. But they could.
On 3/22/2013 12:33 PM, W8AEF wrote:
> Most, maybe all, Yaesu rigs run AFSK. They call it FSK but when you
> look at the schematic you find the AFSK integrated circuit.
>
> de Paul, W8AEF
>
> -----Original Message----- From: Jay WS7I
> Sent: Friday, March 22, 2013 10:07 AM
> To: rtty at contesting.com
> Subject: Re: [RTTY] K3 reduced-bandwidth RTTY analysis
>
> Guess you missed the point. Andy's work was with the K3 which he no
> doubt owns and likes. FLdigi no doubt has facilities to do testing for
> their software and I have major doubts that their are thousands of folks
> running AFSK RTTY on anything in any case.
>
------------------------------
Message: 2
Date: Fri, 22 Mar 2013 14:36:49 -0700
From: Kok Chen <chen at mac.com>
To: RTTY Reflector <rtty at contesting.com>
Cc: "Joe Subich, W4TV" <lists at subich.com>
Subject: Re: [RTTY] K3 reduced-bandwidth RTTY analysis
Message-ID: <8BAAA4EC-B837-4508-8865-D2AB1048814C at mac.com>
Content-Type: text/plain; charset=us-ascii
On Mar 22, 2013, at 1:31 PM, Joe Subich, W4TV wrote:
> Similarly, even ARRL (most specifically W3IZ's review in the current
> issue of QST) do not make the slightest mention of signal purity issues
> like the absolutely horrible transmit phase noise spectrum of the new
> FT-3000.
As bad as the FT-dx3000, its transmit phase noise (about -100 dBc at a 1
kHz offset) is still nowhere close to the interference from an (continuous
phase) FSK signal, whose keying sidebands are in the region of -60 dBc at
the same 1 kHz offset from one of the FSK tones.
You might be confusing the transmit phase noise with the poor reciprocal
mixing (-82 dBc at 2 kHz offset) in the FT-dx3000. The latter only affects
the owner, not the other occupants of the band. But even that number is
still dominated by FSK keyclicks from a signal that is 2 kHz offset away
(although not by much).
One way to look at it is that if you receive with an FT-dx3000, you
probably won't be able to tell if the other people are filtering their RTTY
signals :-).
73
Chen, W7AY
------------------------------
Message: 3
Date: Fri, 22 Mar 2013 17:42:33 -0500
From: Robert Chudek - K0RC <k0rc at citlink.net>
To: rtty at contesting.com
Subject: Re: [RTTY] K3 reduced-bandwidth RTTY analysis
Message-ID: <514CDE59.1070406 at citlink.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
The only way we're going to clean up the bands quickly is to pass
legislation equivalent to the "Cash for Clunkers" program. You know,
something like "Your old rig plus $100 for a brand new K3".
We could then be entertained watching videos on YouTube of Icom 7800's,
Kenwood 990's, Yaesu 5000's, and Swan 350's being fed into scrap metal
crushers.
...well, it was just a thought.
73 de Bob - K?RC in MN
------------------------------------------------------------------------
On 3/22/2013 4:36 PM, Kok Chen wrote:
> On Mar 22, 2013, at 1:31 PM, Joe Subich, W4TV wrote:
>
>> Similarly, even ARRL (most specifically W3IZ's review in the current
>> issue of QST) do not make the slightest mention of signal purity issues
>> like the absolutely horrible transmit phase noise spectrum of the new
>> FT-3000.
> As bad as the FT-dx3000, its transmit phase noise (about -100 dBc at a 1
kHz offset) is still nowhere close to the interference from an (continuous
phase) FSK signal, whose keying sidebands are in the region of -60 dBc at
the same 1 kHz offset from one of the FSK tones.
>
> You might be confusing the transmit phase noise with the poor reciprocal
mixing (-82 dBc at 2 kHz offset) in the FT-dx3000. The latter only
affects the owner, not the other occupants of the band. But even that number is
still dominated by FSK keyclicks from a signal that is 2 kHz offset away
(although not by much).
>
> One way to look at it is that if you receive with an FT-dx3000, you
probably won't be able to tell if the other people are filtering their RTTY
signals :-).
>
> 73
> Chen, W7AY
>
> _______________________________________________
> RTTY mailing list
> RTTY at contesting.com
> http://lists.contesting.com/mailman/listinfo/rtty
>
------------------------------
Message: 4
Date: Fri, 22 Mar 2013 17:31:12 -0600
From: Lee Roberts <ham at n0sq.us>
To: rtty at contesting.com
Subject: Re: [RTTY] K3 reduced-bandwidth RTTY analysis
Message-ID: <8371099.NJzMKdWmWH at server1>
Content-Type: text/plain; charset="us-ascii"
Too bad I don't have narrower transmit filters in my TS2000 for FSK. I
guess if
I want to minimize my bandwidth I'll have to go AFSK with waveshaping or
get a
rig with transmit waveshaping for FSK.
------------------------------
Message: 5
Date: Fri, 22 Mar 2013 19:37:50 -0400
From: Phil Sussman <psussman at pactor.com>
To: rtty at contesting.com
Subject: [RTTY] My thoughts on RTTY analysis
Message-ID: <20130322193750.120853vergwoimoe at pactor.com>
Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes";
format="flowed"
I've been following the thread and now I'm tempted to step gingerly into
the lion's den. From a practical point of view, yes the RTTY analysis is
interesting. However, I've got a point of view.
First, I'll admit that no signal is absolutely perfect. So, in real life
it is a matter of degree. We can approach a 'perfect' signal or can head
to the other end. My ideal is to transmit a 'clean' signal or as clean as
I can make it. It doesn't have to be perfect, it has to be set correctly
and not overdriven. Propagation will twist whatever goes out and I rely
on the ability of a good decoder. Note: I did not say 'perfect' or 'wave
shaped' or 'reconstructed' or 'sampled' or 'filtered' -- I said 'good.'
That's why I personally prefer a piece of professionally designed hardware
to the 'engineered' computer sound card. That's not to say the computer
card can't deliver performance -- of course it can. Yet, a separate stand
alone modem is my preference. It's not perfect, but it works better than
most for me.
Chasing a weak signal in the midst of a plethora of RF is not my style. I
prefer WARC bands or other places of 'quiet.' We ought to assist others by
helping them achieve a good settings and cleaning up the band, not trying
to eke out that last db.
I think of RTTY as a hobby not as an obsession of a perfect RTTY signal.
End of soap box,
Thanks for reading,
de Phil - N8PS
------------------------------
Message: 6
Date: Fri, 22 Mar 2013 17:52:28 -0700
From: Bill Turner <dezrat1242 at yahoo.com>
To: RTTY Reflector <rtty at contesting.com>
Subject: Re: [RTTY] My thoughts on RTTY analysis
Message-ID: <b0vpk898j9t4em65i3fdlnbemp9hfpibe2 at 4ax.com>
Content-Type: text/plain; charset=us-ascii
ORIGINAL MESSAGE:
On Fri, 22 Mar 2013 19:37:50 -0400, Phil wrote:
>I think of RTTY as a hobby not as an obsession of a perfect RTTY signal.
REPLY:
Obsessions found all over the ham spectrum.
There are a couple of subscribers to the Amps reflector who are obsessed
with IMD performance. Meeting the FCC specs is not nearly good enough, they
want way more than that.
It takes all kinds.
73, Bill W6WRT
------------------------------
Message: 7
Date: Fri, 22 Mar 2013 21:06:26 -0700
From: "Jim W7RY" <w7ry at centurytel.net>
To: <k0rc at citlink.net>, <rtty at contesting.com>
Subject: Re: [RTTY] K3 reduced-bandwidth RTTY analysis
Message-ID: <E57A8A28482A41C78C2661FC197253B4 at JimsLaptop>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=response
Oh please!
73
Jim W7RY
The only way we're going to clean up the bands quickly is to pass
legislation equivalent to the "Cash for Clunkers" program. You know,
something like "Your old rig plus $100 for a brand new K3".
73 de Bob - K?RC in MN
------------------------------
Message: 8
Date: Sat, 23 Mar 2013 08:08:11 +0100
From: Walter Dallmeier <walter.dallmeier at dl4rck.de>
To: Contesting RTTY <RTTY at contesting.com>
Subject: [RTTY] First RTTY QRP Contest
Message-ID: <F49DACD5-F8E2-4846-B1EC-0C55A1518831 at dl4rck.de>
Content-Type: text/plain; charset=us-ascii
Hello,
A very interesting QRP RTTY contest is starting tomorrow.
See http://wwqrprtty.jimdo.com/
vy 73 de Walter, DL4RCK
------------------------------
Message: 9
Date: Sat, 23 Mar 2013 10:36:00 +0100
From: Elmar PD3EM <info at pd3em.com>
To: Contesting RTTY <RTTY at contesting.com>
Subject: Re: [RTTY] First RTTY QRP Contest
Message-ID: <E98CC917-A3CC-4283-B07F-84BE19C1FBDE at pd3em.com>
Content-Type: text/plain; charset=us-ascii
Hi,
Looks indeed very interesting to do a QRP RTTY Contest!
I didn't knew about this contest but I'll join.
Hope to see a lot of you on the screen tomorrow!
73, Elmar PD3EM
On Mar 23, 2013, at 8:08 AM, Walter Dallmeier wrote:
> Hello,
>
> A very interesting QRP RTTY contest is starting tomorrow.
> See http://wwqrprtty.jimdo.com/
>
> vy 73 de Walter, DL4RCK
>
>
> _______________________________________________
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> RTTY at contesting.com
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------------------------------
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