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KB2VXA > MARINE 23.03.05 06:06l 33 Lines 1356 Bytes #999 (0) @ WW
BID : 35682_NJ2AR
Read: GUEST
Subj: Re: VK2TV > SSB reduced carrier
Path: DB0FHN<DB0THA<DB0ERF<DB0FBB<DB0IUZ<DB0GOS<DB0EEO<DB0RES<DK0WUE<7M3TJZ<
UA6ADV<HB9AK<K1UOL<K1UOL<WB2QJA<KC2COJ<NJ2AR
Sent: 050322/1519Z @:NJ2AR.#CNJ.NJ.USA.NOAM #:35682 [Lakehurst] $:35682_NJ2AR
From: KB2VXA@NJ2AR.#CNJ.NJ.USA.NOAM
To : MARINE@WW
Hi Ray and all,
You must have missed something so here it is again, SSB reduced carrier
was never used in maritime service. You are correct, the reason why it is
used is for a PLL to lock on to keeping the receiver properly tuned in.
With all the diddling and fiddling hams never worry about drift (if a
good receiver is used, hi) but in long term unattended remote operation
it becomes a problem. Crystal controlled BFOs (the heart of the product
detector) are impractical due to slight drifting of the transmitter. If
the transmitter and the associated receiver drift together no problem
really, but if they drift in opposite directions, well, you know.
Everything drifts over long periods of time which is why engineers have
to correct for it and with complicated communications systems they have
thier hands full so every simplification means less work and less
likelihood of the system owners getting a citation or at the very least a
whole bunch of customer complaints.
73 de Warren, KB2VXA@NJ2AR.#CNJ.NJ.USA.NOAM
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Message timed by NIST: 15:34 on 2005-Mar-22 GMT
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