More on the Kahn Cam-D Demo files

[clouseau]

from http://wrathofkahn.net

As I listen to the stereo version from the "Lab Tuner" I am struck by a couple of things.

1) At 1:40 there is a splice which shows the audio file is capable of dead silence. However the Receiver comes on a couple of seconds later with a noticable Hum (Weird for a demo) and a distictive Hiss.

2) As I listen to the recording, it suggests to me that it is analog. The highs are crisp and "digital like", but the lows are a little mushy to me. Like they are analog. Maybe it's half and half.

3) What a couple of weird selections for a demo. It does not strike me the original has particularly good fidelity, and it's not all that challenging. The results weren't killer either.

4) What's up with the really low level overall?

Anybody else have an opinion on these?

BTW, took the HD car radio to Houston this past week and heard OTA AM-HD for the first time.

Sounds nice. REAL nice.

Coverage - Not as nice. Don't count on AM-HD outside the Sam Houston Tollway.

And yes, it makes AM sound like FM.

KBME and KPRC - NICE.

Sorry Anti guys. To me it just DOES.

Clouseau

 

[LinoNYC]

from http://wrathofkahn.net

As I listen to the stereo version from the "Lab Tuner" I am struck by a couple of things.

1) At 1:40 there is a splice which shows the audio file is capable of dead silence. However the Receiver comes on a couple of seconds later with a noticable Hum (Weird for a demo) and a distictive Hiss.

2) As I listen to the recording, it suggests to me that it is analog. The highs are crisp and "digital like", but the lows are a little mushy to me. Like they are analog. Maybe it's half and half.

3) What a couple of weird selections for a demo. It does not strike me the original has particularly good fidelity, and it's not all that challenging. The results weren't killer either.

4) What's up with the really low level overall?

Anybody else have an opinion on these?
Clouseau

If you read the description: " Stereo Recording
The following recording was made with our lab receiver to demonstrate the compatibility of the Cam-D system with stereophonic transmission."

-Here we have the tricky part, what they are actually presenting is a recording of analog AM stereo which would have to be Khan-Hazeltine and not Cam-D.

So my complaint; we have two pages that imply a demonstration of the digital system, but are only recordings of the analog component, not Cam-D.

Again...Why not!

To add to the air of deception; the site states that cam-D is compatible with AM stereo, however this is only using the Khan system -which has been banned since the formal adoption of C-Quam some 15 years ago.

No demos. No specs. Not even an outline of how the system works.

I went to the website expecting an authoratative presentation similar to what Ibiquity has offered for over 5 years, but came away with the taste of snakeoil.

If the proposing company can't/won't offer anything better than this, there is no point in debating this "system" further.

Lino

 

[vsa]

from http://wrathofkahn.net

As I listen to the stereo version from the "Lab Tuner" I am struck by a couple of things.

1) At 1:40 there is a splice which shows the audio file is capable of dead silence. However the Receiver comes on a couple of seconds later with a noticable Hum (Weird for a demo) and a distictive Hiss.

2) As I listen to the recording, it suggests to me that it is analog. The highs are crisp and "digital like", but the lows are a little mushy to me. Like they are analog. Maybe it's half and half.

3) What a couple of weird selections for a demo. It does not strike me the original has particularly good fidelity, and it's not all that challenging. The results weren't killer either.

4) What's up with the really low level overall?

Anybody else have an opinion on these?
Clouseau

If you read the description: " Stereo Recording
The following recording was made with our lab receiver to demonstrate the compatibility of the Cam-D system with stereophonic transmission."

-Here we have the tricky part, what they are actually presenting is a recording of analog AM stereo which would have to be Khan-Hazeltine and not Cam-D.

So my complaint; we have two pages that imply a demonstration of the digital system, but are only recordings of the analog component, not Cam-D.

Again...Why not!

To add to the air of deception; the site states that cam-D is compatible with AM stereo, however this is only using the Khan system -which has been banned since the formal adoption of C-Quam some 15 years ago.

No demos. No specs. Not even an outline of how the system works.

I went to the website expecting an authoratative presentation similar to what Ibiquity has offered for over 5 years, but came away with the taste of snakeoil.

If the proposing company can't/won't offer anything better than this, there is no point in debating this "system" further.

Lino

You're in New York, as is Leonard Khan. Call him on the phone.

http://www.wrathofkahn.org/wst_page3.html

It's a local call. If he's not in, he may well call you back. Ask him about CAM-D yourself. Khan is an engineer, not a slick salesman.

Has it occured to you that "perhaps" someone might be interested in stealing his ideas and dealing with the courts in the far distant future?

 

[kevtronics]

You're in New York, as is Leonard Khan. Call him on the phone.

Who do people keep misspelling his name!? As you can see on his web site, it's clearly KAHN, not KHAN.

And as for the "stereo" audio clip, it sounds to me like Kahn Power-Side with the "Stereo Effects" option enabled, as received on a Kahn ISB AM Stereo receiver. That's why the audio is tilted off to one side and the stereo separation is limited. If you dig deep on his web site, you'll see a block diagram for a Power-Side exciter, which shows the "Stereo Effects" option.

 

[LinoNYC]

You're in New York, as is Leonard Khan. Call him on the phone.

http://www.wrathofkahn.org/wst_page3.html

It's a local call. If he's not in, he may well call you back. Ask him about CAM-D yourself. Khan is an engineer, not a slick salesman.

Has it occured to you that "perhaps" someone might be interested in stealing his ideas and dealing with the courts in the far distant future?

Come on man, make sense!

I went to that site fully expecting some real information and, barring tech details, atleast valid demonstrations

What I found frankly reeks of fraud.

For two years I have believed that Cam-D was an actual iboc system, eventhough the issue is moot at this point, I assumed that the system was real.

Now I doubt it.

I can understand not divulging details (although Ibiquity did at length) but there is no valid reason not to demonstrate the system, but instead put up ridiculous analog airchecks. Oh and saying that the system is compatible w/AM stereo but omitting that this is only true if you use the obsolete Khan system.

As to "stealing his ideas" (probably all that Cam-D is) a pending patent would deterr that, along with the fact that atleast here in the U.S. the issue of a digital broadcast system is settled and unlikely to ever be revisited.

You can debate the problems with the IBOC-HD system but Cam-D is a dead issue.

Lino

 

[CW]

You're in New York, as is Leonard Khan. Call him on the phone.

Who do people keep misspelling his name!? As you can see on his web site, it's clearly KAHN, not KHAN.

And as for the "stereo" audio clip, it sounds to me like Kahn Power-Side with the "Stereo Effects" option enabled, as received on a Kahn ISB AM Stereo receiver. That's why the audio is tilted off to one side and the stereo separation is limited. If you dig deep on his web site, you'll see a block diagram for a Power-Side exciter, which shows the "Stereo Effects" option.

Maybe we should get William Shatner to YYYEEEEELLLLLLLL it out

His ISB stereo, Power Side and CAM-D all work along the same principles....using one sideband or the other....(since a conventional AM envelope detector only needs one sideband and the carrier to demod the audio)...
the Power Side merely reduces modulation into one sideband....thus reducing adj channel splatter in that direction. CAM-D is analog up to 8-10kHz...the opposite sideband has the digital info in it carrying the L-R and other info in digital mode...but all of it staying within the 10kHz mask better than IBOC and not having digital UNDER analog.....thus increasing the noise in the analog mode. Now HOW he can keep it from fading under overpasses? Unless he uses a buffer in the receiver to hold audio for a few seconds, I cannot see how he can do that on MW frequencies. Regardless of whether its AM, FM, SSB, etc, a MW (530-1705 kHz) signal WILL fade under an overpass, etc....NOTHING can get around the laws of physics, no matter how much you jump and down, scream, throw tantrums, etc....(Even IBOC will go away in that instance). Montgomery Scott said it and it's still true (you cannot change the laws of physics, Capt'n)

 

[Tom Wells]

A pending patent does not deter the unscrupulous. They can simply come close and change enough to avoid infringement.
I am led to believe that CAM-D is both analog and digital, but the digital is only meant to carry upper-frequency info,
which it an do without mauling the main program, which is in robust AM.
The decoded digital info would then "overlay" the analog, providing the extended response.
It may even permit digital and ISB analpog operation.

I too am less than wowed by the sound of the demo, and found the results with Kahn-Hazeltine to sound better
(even on two unmatched radios) than the demo posted.

It does sound like the original recording is fidelity-limited.

I don't see how it could be possible to avoid the effects of diminished signal or various steady-state interference, though.