2 things.....

[alex_hughes]

2 things,

 

Firstly, I have a problem with some Strand Wallrack digital dimmers, or possibly an LSC desk. 8 of the channels don't dim until I've moved the fader on the desk down to about 30%, then they dim very quickly and go dark properly. I've checked the Maximum and Minimum levels on the Wallrack and they're set to 0 and 100% respectively. I hate the desk so don't know what's going on in there. Please, if anyone knows what this may be symptomatic of then let me know!!!!!!!!! I'm currently thinking it's a DMX issue, or possibly

 

Secondly, the other day a student asked me if I know what the C.T. stands for in, for example, 1/2 C.T. straw. I took a random guess and blurted out 'colour transmission or something'. Does anyone actually know what it stands for?

 

My many thanks for all of your time

 

Alex

[Andrew C]

CT = Colour Temperature. Used for correcting an artificial light to sun light, or visa-versa. Or indeed from one artificial source to another. eg tungsten to HMI.

 

Sorry, but nothing to offer on the desk question.

[ianknight]

Alex, it sounds as though the dimmer curves have been set strangely on the dimmer.

 

Before you start really panicking - have a look in the Manual - if there isn't one handy then the Strand website has a PDF you can download (http://www.strandlighting.com) in the Support section. Although I only ever saw the Wallrack unpowered, it seems to have a choice of 4 curves - it should be set to Square or Linear - from your description it might be set to 'Lowcut'. There is an option to reset to defaults - remember what DMX address it was set to though!

 

As to the meaning of C.T. - I bow to the knowledge and expertise of my betters for a definition of that

[matt c]

Not familiar with the desk or the dimmers, but I've heard it mentioned before that some pieces of kit can be programmed with different dimming curves.

 

Perhaps one of them has been set up with a weird curve?

 

Thing to do is to fiddle around. Is the problem unique to channels on the desk, or on the dimmer? Is it a consistent problem?

 

If it's a consistent problem, it's unlikely to be DMX (assuming the general set up is OK (such as cable types, terminators etc.)

 

It's all a far cry form the Zero88 Level 24 I used to play on..

[alex_hughes]

I shall indeed check the curve, Thank you very much to you all!

[aidso]

if memory serves me right there is indeed 4 curves on the wall rack. you set them in the same menu you set the max and min in.

[Kazeja]

Few simple tests to diagnose the problem.

 

 

 

1. Do the suspect channels dim correctly from local control on the front of the dimmer rack?

2. Do the suspect channels dim correctly when patched in the rack to be the same as a working channel?

3. Do the working channels dim incorrectly when patched to be the same number as a suspect channel?

 

 

The fact that 8 of the channels (one third) are misbehaving points to a phasing problem in the rack.

 

4. Is the rack single or 3 phase?

5. If 3 phase, are all the suspect channels on the same phase?

 

Hopefully the answer to these questions will give some idea as to where the problem lies.