Hm...

qwurx [shmem] ~ > perl -le'print pack q/d*/,(1.7453026326120991e+194,1
+.5156845462257262e-147)'
Kerry Chtistmas!
qwurx [shmem] ~ > perl -le'print pack q/d*/,(1.7453026326120998e+194,1
+.5156845462257258e-147)'
Merry Christmas!
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For me, the conversion of 1.7453026326120991e+194 yields 684320797272654B, which is

perl -le '$_=pop;print map{chr hex} reverse /(..)/g' 684320797272654B
Kerry Ch
[download]