My first foray into AM stereo was building the EA kit, and discovering the quality sound of wide-band AM in stereo.

At that time the following stations were transmitting stereo (that I could hear):

Sydney : 2BL, 2GB, 2UE, 2KY, 2UW, 2CH, 2WS, 2SM

Also quite a number of stations throught country NSW, also 2CA in Canberra.

Interstate : 3XY, 4BK, 5AN, and a number of country stations.

Plus many more which I had little interest in.


However over time a number of stations transferred to FM (E.g. 2UW, 3XY and 4BK )


After a while the novelty wore off and the radio was packed away.

I recently plugged it back in only to discover that there don't seem to be any stereo stations left on air.

Does anyone know of any?

I have wondered the same thing having found a Clarion car radio that had AM stereo feature (rare), and wanting to do some home listening, then being disappointed to discover a well known local station had apparently switched off its stereo encoder

Could not get any info from the station and no tech people were available (they seem to use outside tech maintenance contractors).

I'm guessing they used the Motorola C-Quam system back in the early 90s when they called themselves "AM 920 Stereo". Perhaps Motorola required an annual licence fee, so management cost cutters saw this as an easy target? Also Motorola's divisions have been divided up and re-sold a number of times - perhaps to investors looking for patents & licence fees?

VN model Holden Commodores were fitted with Eurovox radios that received stereo AM and the sound was quite good. As these cars were made in the tens of thousands, a wrecking yard would surely have one of these radios available cheaply. Just drive around the country and watch the 'Stereo' indicator light up if it receives such a transmission.

2BS in Bathurst, NSW was one of the last stations that I know of what was still transmitting in stereo (and advertising the fact). Not sure if they still do.

With DAB+ in all the large cities and talk within government of expanding digital radio services, it's a nonstarter that stereo AM will make a comeback.

One other thing - after AM (and FM) eventually stop transmitting, don't expect to receive transmissions over long distances like AM does now. DAB+ sounds great but it just doesn't have the punch to go very far.

The ones I knew of were 2WG, 2CC and 2CA have all shifted to mono, They all look to have the same designator of 18K0A3E
18K0 = 18.0K Channel Spacing
A = AM
3 = Single Channel
E = Audio (Voice/Music)

So for a Stereo AM signal it would need something like 18K0A8E

http://web.acma.gov.au/pls/radcom/client_search.client_lookup?pCLIENT_NO=1102883

I've never heard AM stereo over the air, even though at least one local station did advertise itself as "stereo", there were no radios to be found to receive it! Which must have 'turned-off' (pun intended) AM broadcasters - at least in the US.

I did once run across it at a Convention at the Motorola booth in the late 80s, forget if it was at NAB or AES show, but they had an encoder running that you could listen to with headphones: It sounded really bright so I asked the guy why. He said "oh that's a pre-EQ to compensate for the I.F. roll-off in AM receivers". So kind of like 1980s Dolby stereo for Optical-sound movies which used EQ to make film sound more "Hi-Fi".

Stereo AM became popular here for a couple of reasons I think. The first is the rise of FM which meant AM stations, especially those like 2SM that played rock music were losing their audience. The other was the tardiness of the Commonwealth Department of Communications in letting AM stations shift to the FM band.

When the latter was permitted for two stations in each large city and for existing AM stations to have a supplementary FM station in the same rural market it spelt doom for continued heavy investment in AM stations. AM stations still lead the market in Australian radio but it is only the talkback stations that are in that category.

One thing about stereo AM, because it used the Motorola CQUAM system, overmodulation causes the decoder to drop out on peaks and switch back to mono for a few seconds. Most stations use overmodulation to extend their readability in low signal-strength areas, so remaining in stereo is a big minus (for them).

When I first completed the stereo tuner, 2SM was in the short-lived "Easy 1269" phase. The stereo quality was excellent.

2UW was still working out the kinks, many songs were low-bandwidth, but they worked hard to improve their sound over time.

2CH had other issues, mainly to do with getting the balance control, er, balanced. Often the sound was much louder on one channel than the other.

2BL, 2GB, 2UE and 2KY are talk stations so the use of stereo was of no use to them whatsoever. I did catch 2KY playing some music one day, and it sounded pretty good.

2WS used lots of treble boost and compression, so although it was "stereo", it sounded quite unnatural. Plus the dropouts, of course.

2SM soon decided to switch back to rock music, the controls were all wound to 11, and the excellent quality was gone. Eventually the station fell into other hands, and so they played ad-free for a while, it was this that gave their best ratings in ages. The music was once again easy-listening. Once the ownership issue (or whatever it was) was sorted out, then they went to country music. After that they went to the current talk-back format, and of course no further need of stereo.

2UW became KIX-106 on FM. 2WS became WS-FM. This leaves us just one AM music station in Sydney, that being 2CH. For whatever unknown reason they are in mono, although their stereo DAB signal is quite nice, but limited to the Sydney basin.


I did try to listen to 2CA the other night, unfortunately it suffers severe co-channel interference. In the daytime it is simply not strong enough to overcome the local noise. The best time is in the morning up to about 10 am.

So, in the end, looks like Stereo AM is well and truly gone, relegated to history, just like our valves.


There's a partial schematic of the Holden's AM Stereo car radio on my site.

This leaves us just one AM music station in Sydney, that being 2CH.

... which now insists on identifying itself as "Magic".

Yes, it recently became networked to 882 Magic in Brisbane and 1278 in Melbourne, that's the "magic" bit... the fact that at night time, the content comes from Melbourne.... and nobody is any the wiser.

Nothing magic about it for me. Drives me nuts hearing it said.

If all radio stations simply identified themselves with their callsigns that would be good enough for me. All the stupid names that many stations have used over the years just don't cut the mustard.

I remember 2UW calling themselves Magic 11 for about a year in the 1980s. It is my understanding that Fairfax is going to offload these 'Magic' stations - hopefully the new owner will drop the name and go back to the callsigns. Cheap marketing gimmicks never improved ratings.

I think it's a sign of the slow but sure demise of AM in the city, other than as a medium for gabfests.

"2WS used lots of treble boost and compression, so although it was "stereo", it sounded quite unnatural. Plus the dropouts, of course."

And so, as far as I know, there was already treble boost in the C-Quam-spec encoder, so this 2WS station may have, in ignorance of this, unwisely added their own custom "signal processing" like an Orban Aural-Exciter or BBE + more EQ - not to mention compression to "jazz-up" their sound (like FM stations do). But, as was mentioned, AM stations already drive their modulation high to extend listening range and C-Quam treble boost by itself would dictate dialing back modulation (of important voice frequencies). Creating a conflict with management and thus a financial incentive for switching off the 'stereo box'?

Gosh!

2CA no longer broadcasting in stereo!

I have two AM stereo units, a car radio I bought from Kmart when it was all the rage, and a stereo-component receiver. Both were great units. The car stereo is/was especially good as it has a narrow/wide switch.

I sold the car it was in, so I kept the radio and fitted it into a wooden cabinet with a 4-speaker system. Using a 7AH SLA battery, that unit seved me well as my garage radio.

Unfortunately, 2CA's content got really boring as they seemed to have a very limited range of music. So that radio is now simply an AMP to enable me to listen to internet radio.

Sad to hear it's now useless as an AM stereo reciever.

But to keep with the times, my current car (now) has a DAB radio. Yes, its range is somewhat limitted (actually surprisingly good given the tiny aerial it uses), but its AM section is really good! ABC 666 (Canberra) is easily recieved in Batemans Bay!

Wish I knew VN Commodores had AM stereo! Why do some car makers hide these features?

Yes, it recently became networked to 882 Magic in Brisbane and 1278 in Melbourne, that's the "magic" bit... the fact that at night time, the content comes from Melbourne.... and nobody is any the wiser.

A couple of weeks ago, this was reverted. 2CH is now "2CH Sydney", playing music as before. 1278 and 882 have unfortunately regressed, by joining the 2UE "Talking Lifestyle" silliness / waste of space.