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 mode. 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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