Xref: utzoo rec.ham-radio:11306 sci.electronics:6580 rec.audio:13407 rec.video:6721
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!sharkey!clmqt!flash
From: flash@clmqt.marquette.mi.us (Gary Bourgois)
Newsgroups: rec.ham-radio,sci.electronics,rec.audio,rec.video
Subject: Re: AM Stereo in AUSTRALIA, CANADA, BRAZIL, UK, NEW ZEALAND, S AFRICA?
Message-ID: <631@clmqt.marquette.mi.us>
Date: 12 Jun 89 23:45:25 GMT
References: <4191@bgsuvax.UUCP>
Organization: Enterprise Information System, Marquette, MI
Lines: 38

From article <4191@bgsuvax.UUCP>, by klopfens@bgsuvax.UUCP (Bruce Klopfenstein):
> 
> Does anyone know the status of AM stereo broadcast radio in:
> 
> Canada
> 
> Australia
> 
As you are no doubt aware, in the USA, there are two surviving AM stereo
systems,  namely C-QUAM, and KAHN (ISB).  While Leonard Kahn "invented"
AM stereo in the 60's, and his system is receivable without any special
equipment (Two AM radios one tuned slightly above, and one slightly below
the center frequency), and on those receivers designed for it, the KAHN
system is far technically superior, NONE THE LESS, C-QUAM, by more power
in the marketplace has become the de-facto standard here in North America.

At mmy location here in Marquette Michigan, I can receive several distant
AM STEREO stations, including one from ONTARIO, and it transmits in thee C-QUAM
standard.  I can not imagine the Canadian situation being any different
than here.  IF C-QUAM is not the official standard, it is the DE-FACTO
standard.

In Australia, however, C-QUAM is the ONLY permitted AM STEREO system.

Having listened to C-QUAM and KAHN ISB, as well as the old MOTOROLA systems,
My own trained ear prefers KAHN, although it is now virtually dead.
The problem I have had with C-QUAM is what is called "platform motion"
wherein the center image fades from left to right.  And as a station
gets weaker (as distant stations do, fading up and down) the system
loses "lock" and the image goes in circles, very disconcerting through
headphones.

I realize that few stations are concerned with distant audiences any more
and economics dictates that anyone purchasing broadcasting or receiving
equipment for AM stereo go with C-QUAM.  Were I a media owner, I would
(sadly) install C-QUAM.

From my reading, C-QUAM is the apparent winner world wide.