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CJRobertsIV

Why won't my 633 jam TC to Alexa Mini

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Hi, I posted this in another thread last week and got no response so I'm trying it again here. Would really appreciate some input. 

 

The Alexa Mini has given me a huge headache because I can not get it to jam with my 633 or betso lockit box for the life of me. Ive read through this entire thread and have seemingly tried everyone's suggestions but for some reason my gear will not sync with the two different Alexa mini's I've worked with. Even worse is that I hear from DP's that no other audio mixers have ever had this issue so I look like an idiot. This is the first time I've ever had a technical issue in the field that I was unable to troubleshoot by lunch time of day 1. 

    Any ideas what I'm doing wrong? I am suspicious of the Betso box since it's a word clock out but why wouldn't the camera jam from my 633 directly? 

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Does your gear and the cables you use work fine with other cameras?  Particularly, other Arris?  Is there a camera rental house in your area that might help you try your MO out?

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You should be jamming the Alexa using the TC out Port of the betso not the word clock Port. Make sure Timecode rates are the same and also that the camera is in regen mode. 

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There are Lemo TC cables that are wired directionally for various reasons. 

Maybe try flipping the direction of the cable if they are both Lemos.

Sounds odd but it may be part of the puzzle.

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There’s also another thread where we discussed the mini. With newer firmware, it seems to be necessary to switch “regen” to “jam sync” in the TC menu for the camera to take a jam.

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The timecode frame rate must be the same with project frame rate as DoP or Assistant Camera has been set it up. Project frame rate is on the different menu setting.

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Hello, I know this doesn't help any, not right this second anyway, but this is why I have a lemo 4 pin on my Denecke timecode slate, so that I can show whoever I need to that, yes my time code is working just fine, it's all about your camera. There's always a chance that the camera operator is not telling the truth and they have had lots of problems with the time code in their camera. But who would you think they would rather have get in trouble you or them? Another reason I have that on my slate so I can show somebody that it's working. I don't ask the camera Department to show me how to work something on my mixer, so why is it we have to figure out how to make something work on their camera? Why does the camera department just get to the stand there with their thumb, you know where, while the camera won't accept timecode when they know how to fix this? I had a really bad camera op give me a hard time about doing something on a Red camera, and the director caught her saying that and said make it work. And she did. 

 

Thank you, Martin

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hard to say without knowing what exactly you already tried, but standard trouble shooting would be:

 

- double and tripple check frame rates (as other have mentioned, on the alexa that's two pages to check)

- make sure you try all the different methods regarding regen, preset and jam sync.

- swap out cables to one that is known to work

- use yet another TC generator to test jamming

- try jamming a different mini with the same gear and method (ie at a rental house)

 

if all of that fails it might be that there is a problem with the mini, but nearly all of the problems come down to wrong settings or bad cables.

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16 hours ago, MartinTheMixer said:

Hello, I know this doesn't help any, not right this second anyway, but this is why I have a lemo 4 pin on my Denecke timecode slate, so that I can show whoever I need to that, yes my time code is working just fine, it's all about your camera. There's always a chance that the camera operator is not telling the truth and they have had lots of problems with the time code in their camera. But who would you think they would rather have get in trouble you or them? Another reason I have that on my slate so I can show somebody that it's working. I don't ask the camera Department to show me how to work something on my mixer, so why is it we have to figure out how to make something work on their camera? Why does the camera department just get to the stand there with their thumb, you know where, while the camera won't accept timecode when they know how to fix this? I had a really bad camera op give me a hard time about doing something on a Red camera, and the director caught her saying that and said make it work. And she did. 

 

Thank you, Martin

Hold on Martin

 

4 pin?  The normal Lemo for timecode is a 5 pin !!

 

mike

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Alexas are 5 pin.

Only the wonderlcks at Red wandered into the no man's land of 4 pin Lemo AFAIK.

 

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The Alexa Mini is uniquely finicky, in my experience.  Not every "standard" 5-pin lemo will work, only certain ones.  If I remember correctly, cables listed as bidirectional will not work.  It needs to be a one-way cable.

 

If the cables you have were not specifically listed as compatible with the Mini, then that's likely your problem.  Order a cable that does have that in its description.

 

Once you're certain you have the right cables, I'd also suggest trying different output levels for your TC send, if your gear has that capability.  Start with the highest level possible (which is what most cameras want), and then back it off if that doesn't work.  I don't remember off hand what level the Mini likes best.

 

It's also possible that the port on that particular Mini has gone bad.  Since you said you've had similar troubles with two of them, it's unlikely, but still possible.

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On 1/11/2018 at 10:09 AM, ABBloch said:

The Alexa Mini is uniquely finicky, in my experience.  Not every "standard" 5-pin lemo will work, only certain ones.  If I remember correctly, cables listed as bidirectional will not work.  It needs to be a one-way cable.

 

I'm thinking this must be the issue because my cable works on everything else but I've been unable to jam 3 different mini's now. I have tried all the other troubleshooting tips over and over again.

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According to what I was told by a manufacturer who said they spoke directly with Arri, they confirmed that they made the Mini time code input requirements too stringent.

 

Time code is an audio frequency square wave.  As I was told, SMPTE specs allow for a given amount of rounding of the square wave to still be within specs.  Arri reportedly admitted that they were extra zealous with the Mini's time code input and designed it to require an almost perfect square wave signal.

 

Therefore, anything short of this perfect waveform can be problematic.  Thus the device generating the time code, the cabling, any cabling crosstalk, etc. can be an issue.  For instance, my RX200 time code output isn't welcome into a Mini, even though it works flawlessly with every other camera I've fed with it -- including the Alexa and Amira.  A Denecke box does work on a Mini.

 

 

 

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14 hours ago, CJRobertsIV said:

I'm thinking this must be the issue because my cable works on everything else but I've been unable to jam 3 different mini's now. I have tried all the other troubleshooting tips over and over again.

 

1. Did you check the project frame rate with timecode frame rate on camera settings?
2. Use cables which is not bidirectional, but one way.

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1. Yes and yes.

2. Where do I buy unidirectional cables? 

 

Phillip, I have a good relationship with my local rent house but I usually run tests on cameras owned by friends. I will, however, reach out and see if they have a cable that works if I have another job with a mini before I get one shipped.

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7 hours ago, CJRobertsIV said:

1. Yes and yes.

2. Where do I buy unidirectional cables? 

 

Phillip, I have a good relationship with my local rent house but I usually run tests on cameras owned by friends. I will, however, reach out and see if they have a cable that works if I have another job with a mini before I get one shipped.

 

Sound Devices XL-LL is one example, but you can find a find cheaper one.

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