[Tig] CRT sleep mode

Marc Wielage mfw
Wed Mar 1 19:29:52 GMT 2006

Thanks to oktobor for supporting the TIG
On 3/1/06 8:08 AM, "Ricardo Acosta" <tkvenezuela at hotmail.com> wrote:

> Regarding CRT sleep mode, I??ve been overscanning, defocusing and leaving the
>    current at 150, on an Ursa Diamond. I??ve heard that turning current off
>    completely "poisons the cathode". What is the correct sleep mode for this
>    telecine?

It's been a long time since I've had to operate an Ursa, but the general
rule of thumb I was always told by engineering was:

1) zoom out the raster (overscan)

2) switch focus boards off

3) turn beam current down to almost 0 [but do not turn off]

4) put an opaque card in the gate to block the light path (to save the

We did this for a long time during the 1990s at Complete Post when we had
Ursas in the building (instead of 9 Spirits as we have today), and I was
told that tube life and PEC life was generally fairly decent.

It usually took about 5 minutes for the machines to stabilize after bringing
the beam current back up to 150.

I hadn't heard the comment about "poisoning the cathode" when turning a tube
off, but what is true is that 90% of the time I've had a tube failure
(including light bulbs) has been immediately after a power-on surge.

--Marc Wielage/Senior Colorist
Technicolor Creative Services
Hollywood, USA

NOTE:  The comments above are strictly mine, and may not necessarily
represent those of my employers.

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