I agree with Jeff. I had first-hand experience with both C-QUAM and Kahn and both sounded excellent (when installed, adjusted and maintained properly.) Kahn had the additional advantage that if you were motivated enough to hear AM Stereo, the only equipment you needed consisted of two reasonably-closely matched AM radios. One for each channel.
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- Thread starter Savage
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From the audio clips I heard, the Kahn system sounded flat. From what I've seen it's limited for whatever reason to 6kHz of audio.
The Kahn interference problem that would bother me is that if you're on 1570 & 1560 is blasting in, your left channel gets severely trashed (I used to P.D. a station on 1570 with 227 watts @ night & 1560-N.Y.C. would come barreling in shredding us on 1570 even) but not your right unless you have a strong 1580 there too. Our station DID have Powerside (interesting historical note). This was 2003-2005.
The other reasons I am apprehensive towards Kahn/the system: A. Randy Michaels liked it & shut off all of the C-QUAM exciters when a stereo A.M. station was sold to Clear Channel (except KABL & one other station, I think in Ohio, which from what I understand was written in the contract for their engineers that the stations would continue broadcasting in stereo), B. Kahn's tantrums against the F.C.C. & Motorola, C. the sound quality not being the best. I really didn't like that it's advocates were sour grapes guys.
C-QUAM is a good compromise system because the sound quality is still there (when allowed) & the platform motion problems were fixed in later chipsets. Again, I think the Magnavox system sounded the best.
For full disclosure: what I've heard of Kahn & Magnavox were both recorded from Part 15 signals. I didn't have an A.M. stereo radio before 1993. But there are audio clips on Youtube of WOWO using the Magnavox system.
The Kahn interference problem that would bother me is that if you're on 1570 & 1560 is blasting in, your left channel gets severely trashed (I used to P.D. a station on 1570 with 227 watts @ night & 1560-N.Y.C. would come barreling in shredding us on 1570 even) but not your right unless you have a strong 1580 there too. Our station DID have Powerside (interesting historical note). This was 2003-2005.
The other reasons I am apprehensive towards Kahn/the system: A. Randy Michaels liked it & shut off all of the C-QUAM exciters when a stereo A.M. station was sold to Clear Channel (except KABL & one other station, I think in Ohio, which from what I understand was written in the contract for their engineers that the stations would continue broadcasting in stereo), B. Kahn's tantrums against the F.C.C. & Motorola, C. the sound quality not being the best. I really didn't like that it's advocates were sour grapes guys.
C-QUAM is a good compromise system because the sound quality is still there (when allowed) & the platform motion problems were fixed in later chipsets. Again, I think the Magnavox system sounded the best.
For full disclosure: what I've heard of Kahn & Magnavox were both recorded from Part 15 signals. I didn't have an A.M. stereo radio before 1993. But there are audio clips on Youtube of WOWO using the Magnavox system.
Coolness from the year I was born (1979): http://www.youtube.com/watch?v=2E9SntO4Ul8
This is a demo of the Harris V-CPM A.M. stereo system.
This is a demo of the Harris V-CPM A.M. stereo system.
Speaking of WTVN, I used to pick them as far away as Toledo in Stereo on my Dodge minivan AM Stereo car radio when they played their "Lost 45's" weekends - and it sounded damn good too for the base model radio from Chrysler. The Chrysler AM stereo radios made in the mid 90-s with a 5-band EQ had the 2nd generation CQuam chip and it passed for well-processed FM stereo! The 2nd and 3rd generation chips added a 'mix to mono' to eliminate 'platform rotation' that could occur under certain circumstances (not everyday like Lenny Kahn said).
Also, you are correct about damn Randy Michaels - he forced our station to shut-off the CQuam when Clear Channel aquired the Jacor stations - and that really torqued me off. The engineer there confirmed that he received 'orders' to shut-down a perfectly nice sounding station with a stereo board so that they could broadcast in mono. When they added HD-AM, they did NOT opt to run it in stereo mode, despite still having the stereo board, STL, and all the spots, music beds, etc in stereo. CFCO is Chatham Ontario is still a great station to listen to CQuam music during the day (and I do!)
Also, you are correct about damn Randy Michaels - he forced our station to shut-off the CQuam when Clear Channel aquired the Jacor stations - and that really torqued me off. The engineer there confirmed that he received 'orders' to shut-down a perfectly nice sounding station with a stereo board so that they could broadcast in mono. When they added HD-AM, they did NOT opt to run it in stereo mode, despite still having the stereo board, STL, and all the spots, music beds, etc in stereo. CFCO is Chatham Ontario is still a great station to listen to CQuam music during the day (and I do!)
N1WVQ said:
As a private pilot I've never once used an AM signal for navigation, and I've been doing it for over 35 years.
N1WVQ said:
A station that was running 227 watts compared to a New Yorker running 50kw probably had more issues than the ISB system.
Nevertheless, WQXR sounded great from Toms River/Seaside Heights – a good 55 miles away.
WNBC was also using Kahn’s system during that time. I heard that in stereo well into Virginia on I-95.
When I moved to Sa-ra-so-ta!, 1380 was Q-105’s AM in ISB, 620 was WSUN as country in C-Quam. Now given the signals were not exact, I did my own field test with both of them.
I traveled to Englewood and Ft. Myers. 1380 would have a lot of static. 620 was stronger. But 620’s stereo did not last nearly as far as 1380’s.
When 1280, here was in stereo, the antenna was around the corner. Honk the horn and the station would go mono. The C-Quam had a count that, if interupted, would start over again. If the count was interupted it would not show stereo as long as it was starting over from static or other noise. Kahn did not do that. In fact I say it had 110% coverage because I could pick up the stereo signal when the audio was “in the grass”.
I don’t want a system that limits the range I presently have from the given station. That is not progress.
There in lies the problem with the Ibiquity system…And OTA Digital TV.
Jeff in Sa-ra-so-ta!
Pretty amazing stuff for 450-mile skywave on a cheapo Realistic TM-152 and recorded to Type I cassette. Sounds good even through YouTube's audio encoding.Tom Wells said:
AM (((STEREO))) 1190 WOWO Skywave DX Part 1
http://www.youtube.com/watch?v=9_5QTkGEflQ
AM (((STEREO))) 1190 WOWO Skywave DX Part 2
http://www.youtube.com/watch?v=Wm_iYK-ctiQ
To return to the thread of this discussion... at least briefly... WSCR 670 and WBBM 780 both appear to have their IBOC turned off at the moment. I thought maybe it was just for a game, but it has persisted overnight and this morning. Both sound so much better without the annoying hiss in the background!! Enjoy it while it lasts....
D
Don Juannn
Guest
Tom Wells said:audioguy said:
Both off all day Sunday, and still off when I went in to work tonight.
Listened to wonderful old stuff on WSM all the way to work.
A quick check now still shows no iboc on either.
You are far removed from WSM's protected contours....
http://radio-locator.com/cgi-bin/pat?call=WSM&service=AM&status=L&hours=U
Don Juannn said:Tom Wells said:audioguy said:
Both off all day Sunday, and still off when I went in to work tonight.
Listened to wonderful old stuff on WSM all the way to work.
A quick check now still shows no iboc on either.
You are far removed from WSM's protected contours....
http://radio-locator.com/cgi-bin/pat?call=WSM&service=AM&status=L&hours=U
Honk, Honk. Honk Honk!
Your idea of radio is a weak, small-minded little concept, and far outside the protected contours of the laws of physics.
You can try all you want, but skywave is real, and doesn't respect any definitions or excuses that it "ought not exist".
You are still free to create as much interference to the public airwaves as you can get away with.
Have fun at it, you wild-n-crazy guy, you.
HD on AM is about as effective as the glue used in the roof panels of the "big dig".
"But they said this glue would work!"
Unless of course the idea is to trash the service, then it's doing a pretty good job.
All of you seem to be missing the main reason people don't care for it.
It requires too much babysitting. There is a delay which is established on the digital side and becomes more apparent the longer it is not adjusted. It also is obvious which stations those engineers listen to.
How long is a normal listener going to put up with a 3-10 second delay shifting back and forth before they find other ways to enjoy their listening by other means other than OTA radio?
In short: It is an unstable system and too obvious to the listener.
Jeff in Sa-ra-so-ta!
It requires too much babysitting. There is a delay which is established on the digital side and becomes more apparent the longer it is not adjusted. It also is obvious which stations those engineers listen to.
How long is a normal listener going to put up with a 3-10 second delay shifting back and forth before they find other ways to enjoy their listening by other means other than OTA radio?
In short: It is an unstable system and too obvious to the listener.
Jeff in Sa-ra-so-ta!
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