| |
G0FTD > MARINE 22.03.05 10:38l 48 Lines 1722 Bytes #999 (0) @ WW
BID : 379912G0FTD
Read: GUEST
Subj: Re: SSB reduced carrier-the point?
Path: DB0FHN<DB0MRW<OK0PPL<DB0RES<ON0AR<GB7CIP<GB7SXE
Sent: 050322/0011Z @:GB7SXE.#38.GBR.EU #:25605 [Hastings] FBB7.00i $:379912G0FT
From: G0FTD@GB7SXE.#38.GBR.EU
To : MARINE@WW
I had proposed to send a follow up bulletin on this one but other things
took over.
The general concensus of opinion was that:
A)it helped the receiver tuning for the dummy radio op's
b)it helped convey a partially intelligible signal for those ships still
using an AM rx
c) it was used by coastal stations to provide as near perfect recovered
audio for when link calls were patched into the telephone system.
It all stacks up.
As for repeaters and SSB - well years ago we had in the UK GB3SF ssb
repeater on 145.785 (qth=Sheffield). I used it quite easily with 10w
and a vertical antenn. The rig was a battered old FT480R which I unbalanced
the balanced modulator to give me some pilot carrier.
It worked superbly, but alas with the demise of technical standards over
year the user base diminished (no one wanted to get inside their rigs)
and the repeater closed down.
However at this stage I see a good reason for restarting ssb repeaters -
it's something else the manufacturers can use as a selling point,
it gives the newbies a chance to use a different mode and learn as well
as the old hacks homebrewing/modding again.
Whaddya reckon folks ?
VK2TV wrote:-
>
> This doesn't answer Andy's query re reduced carrier in the maritime
> enviroment but it does offer a reason for using reduced carrier elsewhere.
>
> I recall reading an article many (30+) years ago about a proposal to use > SSB
> in the VHF/UHF Land Mobile Service. If my memory serves me correctly, the
> article came from the UK.
>
> The proposal suggested 10% carrier remained, to enable phase locking the
> receiver to the incoming signal, to ensure the receiver was always "tuned
> in".
Read previous mail | Read next mail
| |
