Broadcast Legal Specs DL-860 serial digital legalizer

[Bob Zelin]

If you have a HD scope, it’s the same damn standards as always – 0 and 100 (700mV). Your HD scope has graticule markings for where your levels need to be. If you don’t have a HD scope, but have an HD legalizer – well, I think that is pretty funny.

Bob Zelin

[Nick Gardner]

Yes, thats very helpfull. I have a waveform/scopes. I was refering to milivolt levels per chanel in color, etc. There are more factors than Luma, and I was looking for some numbers to punch into the machine for initial set up.

Anyone have any useful information? I guess I can always call Harris.

Thanks,

Nick Gardner

[Arnie Schlissel]

I doubt that Harris can be specific. There’s a reason why they give you all those settings to adjust. It’s because every broadcaster has their own spec. You need to speak to an engineer at whichever broadcaster is recieving your tape to find out what their delivery requirements are.

[Rob Gardner]

Hi,

Thanks for the response. I guess I need to get on the phone with an engineer. The deliverables list is not very specific.

Thanks again,

Nick

[Nick Gardner]

Hi,

If it helps anyone else, here is the info I was looking for.

100 IRE = 714mv
0 IRE = 0mv

Cheers,

Nick

[Joseph Owens]

It is possible to do the math:

It has been long established that 1 volt encompasses the range of values between “sync tip” and “peak white”, which corresponds to 140 IRE units. Peak White is commonly identified as 100 IRE; in digital space Black is “0” (in analog: +pedesal black which sits at 7.5 IRE), and Sync Tip is down at “-40″ IRE”. Divide 100 by 140 and see what you get. Burst is 40 units… +/- 20 units around 0.

As far as legal limts go, it is correct to review your broadcaster’s deliverables. As a rule of thumb 0-100 will get you in no trouble, but there are tolerances, and typically 102 IRE is the maximum allowable for Luminance ONLY, but for combined-chrominance in composite space 120 IRE is usually the upper limit, with a lower limit that takes the same overshoot into account.

If you have something like the Harris/Leader TVM-900, use the “Iris” display with gamut alarms — the inside/outside rings light up to alert you to the presence of disallowed-gamut levels.

Really quite helpful.

JPO

[Jeff Witman]

I am the product manager for the DL-860 legalizer and will glady help you resolve this issue. you can email me directly at jeff.witman@harris.com.
The limits that I can recommend are only recommendations. The limits are ussually set by the customer.

RGB limits are
RGB Maximum mV 700
RGB Minimum mV 0

Encoded (composte NTSC
NTSC Setup IRE 7.5
Luma Blk Clip IRE 0.0
Luma Wht Clip IRE 100.0
Composite Lower IRE -20
Composite Upper IRE 120
Chroma Amplitude IRE 120.0