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PF1F > MARINE 15.03.05 21:56l 44 Lines 1784 Bytes #999 (0) @ WW
BID : C10084PF1F
Read: GUEST
Subj: Re: SSB supressed carrier
Path: DB0FHN<DB0FOR<DB0SIF<DB0EA<DB0ACC<DB0GOS<DB0EEO<PI8DAZ<PI8WFL
Sent: 050315/2044Z @:PI8WFL.#NH1.NLD.EU #:29422 [Enkhuizen] $:C10084PF1F
From: PF1F@PI8WFL.#NH1.NLD.EU
To : MARINE@WW
KB2VXA wrote:-
>
> I hate to be the one to inform you that since SSB has no carrier to be
> reduced the term is supressed. That is it's partially removed from the
> original AM signal along with the opposite sideband.
The original question of G0FTD was about marine radio.
I know about marine radio.
"Single Sideband" means just that- not two, but one sideband.
In ITU parlance, the carrier is not yet specified.
Three flavours of SSB exist, then, as far as Andy's radio is concerned:
with Full, Reduced, or Suppressed carrier.
Reduced carrier was never actually used in marine radiotelephone.
Full carrier did see some use. I had to use it for a spell to call old
coast stations in strange backward lands. Then they caught on as well.
There is no contradiction there, just a different mode: A3H vs. A3A as
marked on the earlier SSB sets, later called H3E vs. R3E.
The "aid in tuning" reason was in itself valid - those old receivers could
be tuned into zero beat and out the other end. The sweet spot was in
between!
But, as I said, it never caught on - no need.
There were no marine radios in commercial use that locked onto a reduced
carrier. No Sailor, Skanti, Debeg, Hagenuk, Telefunken - no ITT Mackay
Marine either, for that matter.
Oh, a Collins, perhaps; it would be just up their alley. But the one I
operated did not.
I have no knowledge of practical broadcast applications. I have heard many
SSB transmissions of broadcasters, mainly relays, most using ISB (so able
to carry two programs on one assigned (double sideband) channel, but not
much carrier, at least not on the 19 and 20 MHz VOA relays I heard at the
time (those were the eighties). But there may very well have been.
Rudolf, PF1F
Heemskerk - JO22im
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