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<font face="Verdana">In the last few weeks while operating FT8 I've
seen calls from Nigeria (ATNO for me), North Korea (ATNO for most
everyone) and Antarctica that were suspiciously loud and
completely unresponsive to my calls. A quick check of QRZ.com
indicated that there was no info on these calls. I was
experiencing an FT8 'hash collision'.<br>
<br>
The short version of the story is that the FT8 protocol uses a
shortcut (a hash code) to send some callsigns. In some rare-ish
cases it is possible for multiple call signs to have the same hash
code value. For example (this is a made up example), 'PY2PEACE'
could share the same hash code as 'P5AXXX'. So while PY2PEACE is
active on FT8 it may appear in your decode list as P5AXXX. You
start frantically calling P5AXXX with no response. There is a
much longer, and detailed description of the issue here:
<a class="moz-txt-link-freetext" href="https://bit.ly/49AnNOC">https://bit.ly/49AnNOC</a><br>
<br>
So if you happen to run across a P5 on 10m FT8 and it is not under
the Mother-of-all-pileups you can simply restart your FT8 software
and it will rebuild the hash code table. This will work a lot of
the time, but not always. So do a little research on that
too-good-to-be-true call before you tape down your 'Enable TX'
button.<br>
<br>
73,<br>
Tim - K1DC<br>
</font>
<div class="moz-signature">-- <br>
<p
style="font-family:Verdana, Geneva, sans-serif; font-size:10px; -webkit-margin-after:.5em; -webkit-margin-before:.5em">Courageously
sent from a non-Apple device that <em>includes</em> a headphone
jack.</p>
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<td width="150"><a
href="https://k1dc.com/img/k1dc-qsl-card-front.png"><img
role="presentation"
src="https://k1dc.com/img/k1dc-qsl-card-front-sm.jpg" width="130"></a></td>
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<h3>Tim Carter - K1DC (was KC1RET)</h3>
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<td><a href="tel:1.978.710.0133">+1.978.710.0133</a></td>
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<td><a href="mailto:k1dc.radio@gmail.com"
class="moz-txt-link-freetext">k1dc.radio@gmail.com</a></td>
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<td><a href="https://k1dc.com"
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<p>"Computers are incredibly fast, accurate and stupid;
humans are incredibly slow, inaccurate and brilliant;
together they are powerful beyond imagination." -- <i>Albert
Einstein</i></p>
<p
style="font-family:Verdana, Geneva, sans-serif; font-size:10px; -webkit-margin-after:.5em; -webkit-margin-before:.5em">Warning:
Spelling errors in this message are the product of a
poor school system. Pay teachures more than athletes.<br>
This email is intended for the use of the individual
addressee(s) named above and may contain information
that is confidential privileged or unsuitable for overly
sensitive persons with low self-esteem, no sense of
humor or irrational religious beliefs. If you are not
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or copying of this email is not authorized (either
explicitly or implicitly) and constitutes an irritating
social fauxpas. No animals were harmed in the
transmission of this email, although the mutt next door
is living on borrowed time, let me tell you.</p>
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