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Re: Topband: FT8 qrm

To: <topband@contesting.com>
Subject: Re: Topband: FT8 qrm
From: "Dave AA6YQ" <aa6yq@ambersoft.com>
Date: Wed, 29 Nov 2017 12:59:30 -0500
List-post: <mailto:topband@contesting.com>
1. I operate both CW and FT8 on 160m, and am far from unique in that regard.

2. WSJT-X, the application many FT8 ops utilize, includes a waterfall display 
that shows CW signals

3. WSJT-X gives its users control over where they transmit, so a "pre-existing" 
CW signal can be avoided

4. WSJT-X could be extended to be able immediately stop decoding FT8 (or JT65) 
signals and send QRL in CW at a frequency designated by clicking in its 
waterfall; many FT8 users employ relatively low power with modest antennas, 
however, so this may not always be effective.

5. It's not unreasonable to expect competent ops to be aware of what modes are 
typically used in what segments of a band, and to listen for an appropriate 
length of time before first transmitting to ensure they don't QRM an ongoing 
QSO.

      73,

          Dave, AA6YQ

-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Tim Shoppa
Sent: Wednesday, November 29, 2017 7:53 AM
To: Wes Stewart
Cc: topband@contesting.com
Subject: Re: Topband: FT8 qrm

You don�t understand how the FT8 guys work. They have a 2kHz slice they all 
work in whether they were there first or not by usual CW practice. They only 
transmit every 30 seconds and no CW operator is gonna wait a whole 30 seconds 
for a response to QRL?.  Not that a FT8 guy can respond to a QRL anyway. The 
vast majority of FT8 guys do not operate CW anyways.

So that 2kc slice it�s not a matter of who was there �first� by CW standards. 
The FT8 guys have been there since June of this year and to them, June is when 
they were there first.

And if a CW guy fires up 1-2kc away from a weak warbly FT8 carrier,  he thinks 
nothing of it. And if the CW guy is anywhere in the wide 2kc FT8 slice then all 
FT8 operators will regard it as QRM that renders the entire slice worthless.

It is odd that we have two fundamentally narrow bandwidth modes yet they do not 
coexist well. It�s ridiculous to think they could coexist in a contest weekend 
anyway. Those FT8 guys that were rudely surprised by CW this past weekend, 
that�s nothing compared to what�s gonna happen this coming weekend.

Tim N3QE

> On Nov 29, 2017, at 7:29 AM, Wes Stewart <wes_n7ws@triconet.org> wrote:
> 
> My scenario had the CW man on the frequency FIRST.
> 
>> On 11/29/2017 4:54 AM, Tim Shoppa wrote:
>> A typical CW guy will hear FT8 or JT65 as a kinda whiny wobbly intermittent 
>> carrier. And will probably think it�s just some neighborhood switching power 
>> supply noise. He won�t CQ right on top of it (because he wants to hear a DX 
>> respondent) but he will have no problem firing up 500 Hz away.
>> 
>> But the digital guys e.g. FT8 have 2khz wide filters. So there is a 
>> fundamental assymetry here.
>> 
>> Tim N3QE
>> 
>> 
>> Sent from my VAX-11/780
>> 
>>> On Nov 28, 2017, at 10:50 PM, Wes Stewart <wes_n7ws@triconet.org> wrote:
>>> 
>>> So what's the protocol when a CW man checks a frequency, hears nothing, 
>>> sends a couple of QRL? and hears nothing and begins to run stations.  Then 
>>> sometime later a guy running an imaginary mode...oops...sorry, FT8 shows up 
>>> and wants to park on the CW man's frequency?  Who is to blame?  I'll answer 
>>> my own question: the FT8 guy who is QRMing an occupied frequency.
>>> 
>>> Besides the FT8 guys can always resort to JTAlert to QSO via text messaging 
>>> as one west African station apparently tried to do with me.
>>> 
>>> Wes  N7WS
>>> 
>>> 
>>>> On 11/28/2017 10:45 AM, Bryon Paul Veal N�AH wrote:
>>>> There were ops all over the FT8 segments, refused to even try and work 
>>>> them and some were some pretty rare mults for CQWWCW...gentleman 
>>>> agreements are of the past.....sucks
>>>> 
>>>> PAUL. N0aH
> 
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