[GreenKeys] Mark/space reversed ?

[uncle_fred1 at juno.com]

  High audio tone on LSB is low RF frequency, correct?  That could account for the AF/RF relationship.

  Also, while on the subject, which is "more" correct: specifying Mark low or Space high?   

Fred


---------- Original Message ----------
From: Jim Haynes <jhhaynes at earthlink.net>
To: Ralph Mowery <rmowery28146 at earthlink.net>
Cc: greenkeys at mailman.qth.net
Subject: Re: [GreenKeys] Mark/space reversed ?
Date: Sat, 26 May 2012 21:37:06 -0500 (CDT)


Well back in the 1950s hams and commercial and military mostly made
the space frequency the lower of the two on RF.  But at audio it was
the higher of the two, for reasons I never understood.  There was the saying LSMFT - Low Space Makes Fine Teletype (copped from a Lucky Strike cigarette slogan).  But there were a few stations even then that used
reversed shift.  Since then there has been some military stuff that
operated with space high - perhaps as a consequence of some military
gear being upper-sideband-only and keeping the space high convention
for the audio signal.  And in general companies today use whatever
shift polarity they please.

 


____________________________________________________________
NetZero now offers 4G mobile broadband. Sign up now.
http://www.netzero.net/?refcd=NZINTISP0512T4GOUT1