[Boatanchors] double-sideband suppressed-carrier

[Richard Knoppow]

----- Original Message ----- 
From: "Gary Schafer" <garyschafer at largeriver.net>
To: "'rbethman'" <rbethman at comcast.net>; 
<boatanchors at mailman.qth.net>
Sent: Sunday, October 19, 2014 6:04 PM
Subject: Re: [Boatanchors] double-sideband 
suppressed-carrier


> As I recall the Costas receiver derived the carrier for 
> reinsertion from the
> two coherent side bands by limiting and rectifying them.
> With this system the carrier was always exactly in proper 
> phase with the
> side bands so that they could add their outputs. No pilot 
> carrier was
> required to synchronize.
>
> This would not work on SSB however. To receive SSB a 
> separate BFO had to be
> switched in.
>
> 73
> Gary K4FMX

      This is the way I always understood the system to 
work. The detector was essentially a synchronous detector so 
that the two sidebands were added coherently. That gave the 
system the same power advantage as SSB when the carrier was 
suppressed. The receiver ignored the carrier and could be 
used for conventional AM with the advantage of significantly 
reducing the effects of selective fading.
     I thought that Leonard Kahn proposed a similar system 
but I am not sure and when I did a literature search could 
not find anything.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com