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Re: Topband: FT8 on 160 - how you can make a difference

To: W0MU Mike Fatchett <w0mu@w0mu.com>
Subject: Re: Topband: FT8 on 160 - how you can make a difference
From: Cecil <chacuff@cableone.net>
Date: Sat, 3 Aug 2019 16:32:13 -0500
List-post: <mailto:topband@contesting.com>
I worked very little DX on 6M until FT8 so there is still something more going 
on than you have discovered in your testing.

Cecil
K5DL

Sent from my iPad

> On Aug 3, 2019, at 4:23 PM, W0MU Mike Fatchett <w0mu@w0mu.com> wrote:
> 
> Have you attempted to open a conversation with the creators of the mode and 
> discuss what you are seeing?  They seem like they are quite knowledgeable.  
> How can you disprove their claims of weak signal mode when you are not sure 
> how they are coming up with their numbers?
> 
> I never heard EU or JA on 160 until I tried FT8 last year.  I never once 
> heard any dx on CW last season although many tried as the devout 6M ops have 
> a chat room where there were countless tries on other modes but only contacts 
> made on FT8.  Why is that?  No longer do you have to have stacks or H frames 
> to work Gud DX on 6m.
> 
> W0MU
> 
> 
>> On 8/3/2019 1:28 PM, K4SAV wrote:
>> There is growing trend on 160 that I find disturbing and that is for major 
>> DXpedition to use FT8 for all or mostly all 160 operations. They do that 
>> because they "know" that FT8 is ideally suited for weak signal operation.  
>> They have read that and are continually told that by everyone.  Rare 
>> countries on 160 is synonymous with weak signals and poor signal to noise 
>> ratios.
>> 
>> I know of no one that has done the same tests that I posted to Topband.  I 
>> have had people agree with me but that was because they liked my answers, 
>> not because it agreed with their measurements.  I have had many people tell 
>> me I am wrong and they sited the official documentation as proof that my 
>> measurement were wrong.
>> 
>> So if you would like to join the ranks of myth busters, start doing some 
>> measuring.  WARNING, Myth busting of all types in ham radio is a never 
>> ending effort.  As soon as you bust one, two posts later someone will repeat 
>> it again. Sorry, I don't have any caps, pins, or t-shirts to sell.
>> 
>> If enough people start characterizing this mode maybe the more experienced 
>> people in radio will sit up and take notice.  One or two posts by a single 
>> person isn't going to do it.
>> 
>> You are not going to kill FT8 no matter what you do or how feel about it.  
>> It will always be a home for those they can't copy CW, and for those that 
>> don't like CW, and for a few others for a variety of reasons.  I can't see a 
>> problem with that.  The problem I see is with FT8 and major DXpeditions.  I 
>> also see some FT8 only DXpeditions but those are usually vacation part time 
>> to non-rare countries.  Can't worry about those.
>> 
>> For people that can't copy CW, FT8 is very attractive.  It will allow them 
>> to work some DX on 160.  In the winter I see Europe appearing on FT8, so 
>> that can be worked from the eastern US. Invariably when I measure the 
>> strength of those stations, they are close to S6.  That would be arm chair 
>> copy on CW with a receiver that sits on S1 on noise.
>> 
>> So contribute to the ham radio knowledge data base by making some 
>> measurements.  I described my measurements in a previous post. Figuring out 
>> what the reported S/N number means is interesting but the more important 
>> question is what is the minimum signal to noise ratio this mode will decode. 
>>  Sitting up a test for minimum signal is a little tricky because there are 
>> so many FT8 stations on at any one time, there is almost never a nearly dead 
>> band.  I simulated that on 160 by waiting until the first stations from the 
>> NE showed up on the band (just after their sunset) and turning my antenna 
>> away from them so as to decrease their strength and bring up the noise from 
>> other directions.  When I wait until sunset occurs in more locations, my S 
>> meter hangs at about S9 +20 to 30 dB no matter which direction I point my 
>> antenna.  I tried doing this on 6 meters but often there was nothing there. 
>> I suggest doing measurement first in normal decoding mode, then test what it 
>> does in deep search mod
 e.  Be careful how you switch modes.  FT8 likes to memorize the band and make 
guesses in deep search mode.
>> 
>> You can try doing the minimum S/N test in a crowded band instead of a nearly 
>> dead band but I don't think you will ever find it decoding a weak signal.  
>> You have to measure the noise levels and signal levels.  You can't use the 
>> reported S/N number.
>> 
>> If you make some measurements, post them.  I would really like to hear what 
>> others find, especially if they happen to disagree with what I measured.
>> 
>> I don't have a pony in the dog and pony DXCC race so I don't have an opinion 
>> there.  I love working DX on 160 but collecting cards was no fun.  So years 
>> ago I decided to only do the fun part.  I compete with myself, no one else, 
>> and I don't get bragging rights, but I don't do this for bragging rights.
>> 
>> Jerry, K4SAV
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