1979 Harris AM Stereo demo LP (Side B)

This is the long awaited Side B of the Harris AM Stereo demo LP, which I am finally able to upload due to the music samples no longer being blocked worldwide on YouTube. Side A was previously uploaded back in March 2010. This side of the disc was unfortunately stamped off-center, so you might hear some pitch variations at times. Stay tuned until 8:42 to hear a rare aircheck of 800 CKLW broadcasting in Harris AM Stereo in 1979!

Harris V-CPM was one of five AM Stereo broadcasting systems proposed to the FCC in the late '70s. In 1979, Harris put out this 45 rpm LP (also available on reel-to-reel tape) to demonstrate the performance and tout the advantages of their system.

The Harris V-CPM system was the most technologically advanced and arguably the best performing AM Stereo system, but it was also the most complex and costly to implement. In 1984, Harris modified their system to be compatible with Motorola C-Quam, which was becoming the de facto standard for AM Stereo, and began building Motorola-licensed C-Quam equipment for radio stations.

In 1993, the FCC belatedly chose Motorola C-Quam as the USA's single standard for AM Stereo broadcasting, after Australia and Canada had already done so in 1985 and 1988, respectively. Numerous C-Quam AM Stereo stations remain on the air today worldwide, but along with the Magnavox, Kahn/Hazeltine, and Belar systems, the Harris system has long since been rendered defunct.

Category:

Science & Technology

Tags:

• harris
• cpm
• vcpm
• v-cpm
• am
• stereo
• broadcasting
• demo
• demonstration
• lp
• vinyl
• record
• 1979
• 45
• rpm
• motorola
• c-quam
• cquam
• fcc
• system
• kahn
• hazeltine
• isb
• magnavox
• pmx
• cklw
• aircheck
• vintage
• classic

[uxwbill]

I didn't notice much difference between "turntable" and "V-CPM". That air check sounded pretty good--I take it that is included on the record as well?

What is that glowing (?) green number at the mid-left edge of the background?

[vwestlife]

@uxwbill Yes, and there is another CKLW aircheck on Side A. (The liner notes mention that they were broadcasting using pre-emphasis, thus explaining the somewhat shrill sound, compared to the laboratory test recordings.) The green thing is the reflection of the hologram on a UL sticker on the bottom of a "power center" that I have sitting vertically behind the DeskPro EN's monitor.

[thelasthallow]

this is pretty cool. is the Harris AM stereo record rare?

[vwestlife]

@thelasthallow I know of one other AM Stereo enthusiast who has one.

[bratina501]

@uxwbill You are right about some modern HD Radio tuners decoding C-QUAM I happen to have one that does. Radioshack sold one under the Accurian name which decodes analog AM stereo but only certain models do. Mine has the date code 09A06 which means September 2006 and made during shift A. This might be unofficial because it was dropped in later versions of the Accurian tuner as people with some made after September 2006 have not noticed AM stereo decoding. It seems hit and miss sadly.

[vwestlife]

@uxwbill I believe WSM said they discontinued C-Quam in order to prepare for transmitting IBOC/"HD Radio", which they did use for a few years, but now their signal is back to plain analog mono.

[uxwbill]

@xmaddict The reason may have had more to do with keeping their stereo generator alive and working correctly. I don't know what the parts landscape looks like, though I think Freescale/Motorola still markets C-QuAM decoder ICs.

There are lots of older tuners out there that support the format, including Delco's fairly common UX1 radio. Some modern HD Radio tuners will also (unofficially?) decode C-QuAM AM stereo broadcasts.

[EastAngliaUK]

Sounds really good on youtube can here the stereo quite well but must be way better to here in real life.

[rhblakeman]

I personally prefer AM over FM and with stereo think of how far an advertisement for a business or product would go (distance) on AM stereo if it were to become a popular broadcasr band again. Only people I know listening to AM anymore are the talk show and George Noory fans. I only listen to WHAS 84 on AM when I'm on the road and the weather looks bad.

[rhblakeman]

I've heard of AM stereo and know some stations were equipped but I don't think I've seen any AM Stereo receivers.

@Xmaddict - What was the name of that big band & swing station at 1640 AM in Nashville? I used to listen to them everytime I was between Bowling Green KY and Nashville - then they went silent one day.

[xmaddict]

WSM in Nashville, TN used to broadcast in AM Stereo until 2000. Sadly they stopped. Declining market?

[fmbroadcast]

Ohh I love it. So nice. Thank you for such a plaisur. The music Is so good.

Turn table / VCPM ahhhh so goood

Turn table / VCPM <3 <3 <3