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ERX hard wire timecode jam


fieldmixer

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"One can argue that in those cases I should be using Lockits of some description"

Yes you need to use the right tool for the job at hand. 

 

" I've certainly had cause to be separated from the ERX for longer on multicam shoots"

How far and how long. Are we talking 20 mins or 2 hours if its the later see the previous response.

 

 

 

 

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For the people who are claiming false advertising or bitching about semantics the question boils down to what do you considered an extended dropout.

Is it 1 second? 1 minute? 1 hour? Or is it more?

 

And if you are ERX user have you ever had any sync issue do to the "extended dropout"?

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...

I note that we are also discussing a historic quote from the old Zaxcom website. There is nothing in the current manual or product information from which to establish the ERX sync abilities when out of Zaxnet range.

 

I referenced the previous Zaxcom web site for clarification as someone had speculated in an earlier post that it might have misled them.  For further clarification, the current web site states:

 

"Mounted on a camera or slate the ERX2TCD can provide frame accurate timecode with no drift since it is constantly receiving and updating its timecode from the source."

 

...so the current web site is equally innocent of misleading as to the use of an ERX. 

 

Quite frankly, even if the ERX were a free-standing time code unit, I'd still use a Denecke box for that application as I find their devices generate a more accurate, and stable, reference.  In my experience, even their older SB2a, when properly calibrated, can maintain time code as tight as a tenth of a frame over several hours.  However, for the reality gig I just worked several months on, the ERXs were awesomely cool.

 

It's a matter of choosing the right tools for the job.

 

What happens all too often in this internet world, is that a person will start speculating about possible features of a given device, and someone scanning for a quick dose of instant knowledge will then make assumptions and repeat that information as if it is factual, which of course, it's not.  Always remember that the internet is a hotbed of people talking about things they know little about.

 

...Which leads me to the conclusion that perhaps I'll shut up now <grin>.

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I'm not complaining about the ERX at all. Let's knock that on the head right now. I've merely been made aware of a limitation that I was previously ignorant of.

I've also been onto the Zaxcom forums and FB page to reach out to Glenn and co about the specs on the ERX (I will also email). This is not criticism either.

I don't see anyone claiming false advertising. An absence of exact details for a given situation does not equate to this.

There *might* possibly be a disconnect over the fully defined specifications of the ERX receivers amongst *some* recordists. Clearing this up is a good thing.

I'm very fond of my ERX so any concerns I have come from a good place.

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"Yes, but the clock accuracy of the Nomad is also the same as the ERX."

 

This is not a correct statement.

 

Nomad is calibrated to GPS time and has a temperature compensated oscillator just like all Sync boxes. This is not the same at all as our ERX. Yes, the ERX will not drift when used as directed.

 

Glenn

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I would also point out that the ERX is tiny. All these weird C300 camera rigs would prefer not to have a 411/QRX and a SB-3 mounted on them because there often just isn't room. We also know the C300 (or a Red) drifts like crazy just from occasional jams, so compared to any of that, the ERX is a great combination of size and service. 

 

I worked on something recently where I put the QRX100Q+QIFB (which has TC out) on the A camera's PIX240 and an ERX on the B camera's PIX240. The other mixer they use for some episodes just jammed his 788T to the PIX every so often. On paper, that should be great. They had huge problems with the other guy's setup being out of sync and specifically requested I use my Zaxcom system for the next episode I do. This shoot had cases where we flew in 2 different planes so the B cam could advance and see our airplane land. The B cam ERX was out of range for an hour or two and that worked fine. If I was putting a TC system in a rally car and setting it loose for 12 hours, I would use an SB-3 with lithium batteries, but for most everything I have done, the ERX seems to be a huge step up from "jam twice a day".... especially considering how many doc/reality shows shoot with cameras that can NOT carry TC that long.  I would consider a Denecke sync box the gold standard, and I own a few, but for many cases the smaller and lighter ERX is more than adequate (and includes scratch audio). The ERX display is a nice touch for ACs that like the visual check, or note takers. 

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"Yes, but the clock accuracy of the Nomad is also the same as the ERX."

 

This is not a correct statement.

 

Nomad is calibrated to GPS time and has a temperature compensated oscillator just like all Sync boxes. This is not the same at all as our ERX. Yes, the ERX will not drift when used as directed.

 

Glenn

I stand corrected.

 

My comment is based upon the spec details for the Nomad on the Zaxcom website which lists the clock accuracy as 1.54PPM (1 frame out in 6 hours). This same figure is given for the ERX in it's manual.

Glenn, what is the official Zaxcom line on possible drift when out of signal over several hours? We have John's test on here, but I'd love to hear what the manufacturer says.

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I would also point out that the ERX is tiny. All these weird C300 camera rigs would prefer not to have a 411/QRX and a SB-3 mounted on them because there often just isn't room. We also know the C300 (or a Red) drifts like crazy just from occasional jams, so compared to any of that, the ERX is a great combination of size and service. 

 

I worked on something recently where I put the QRX100Q+QIFB (which has TC out) on the A camera's PIX240 and an ERX on the B camera's PIX240. The other mixer they use for some episodes just jammed his 788T to the PIX every so often. On paper, that should be great. They had huge problems with the other guy's setup being out of sync and specifically requested I use my Zaxcom system for the next episode I do. This shoot had cases where we flew in 2 different planes so the B cam could advance and see our airplane land. The B cam ERX was out of range for an hour or two and that worked fine. If I was putting a TC system in a rally car and setting it loose for 12 hours, I would use an SB-3 with lithium batteries, but for most everything I have done, the ERX seems to be a huge step up from "jam twice a day".... especially considering how many doc/reality shows shoot with cameras that can NOT carry TC that long.  I would consider a Denecke sync box the gold standard, and I own a few, but for many cases the smaller and lighter ERX is more than adequate (and includes scratch audio). The ERX display is a nice touch for ACs that like the visual check, or note takers. 

I adore my ERX for just these reasons. I do seem to have been using it at the very limit of it's possibilities so wanted a definitive on that. In all honesty I have yet to have any complaints from post, but sometimes that is a 'until next time' scenario.

As Zaxcom obviously encourage adoption of a fully networked system between recorder, wireless, IEM and timecode using Zaxnet, I wonder if there would be a market for a unit that had the same ERX functions but also that of a full lockit device? This might logically have an effect on the ERX size, but it would use all the advatages of Zaxnet and keep things 'in house' rather then going to second party manufacturers for timecode.

Would this be something people might conceivably pay money for?

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JB : " "It was extended dropout."::)

 

JA: " (and then abruptly be corrected when back in range).:blink:

by a whole 1/4 frame...  8)

" It would be interesting to see if in any future 'ERX3' Zaxcom could employ a crystal sync in the receivers that could work like the Lockits and TCBuddies "

well it is possible, but not necessarily probable, and, IMO not particularly "interesting"

" I should be using Lockits of some description,  "

for those of you who are bitchin', it seems you did not do your homework, and maybe did not make the correct choice in your purchases...

as Mark O said: " Ultimately, the end user is responsible for understanding the limitations of his/her equipment. If you don't know or are uncertain, the manufacturer is only a phone call or email away. And Zaxcom is one of the easiest companies to get a hold of. "

(and thanks for the new Senatorium!)...

tough room... :wacko:

JB noted: " a person will start speculating about possible features of a given device, and someone scanning for a quick dose of instant knowledge will then make assumptions and repeat that information as if it is factual, which of course, it's not.  Always remember that the internet is a hotbed of people talking about things they know little about. " really tough...

for example:

JA: "  "Yes, but the clock accuracy of the Nomad is also the same as the ERX."

 

refuted by the proper source, the manufacturer, Glenn: This is not a correct statement... Nomad is calibrated to GPS time and has a temperature compensated oscillator " see what I did there ?

 

and, JA: " I'd love to hear what the manufacturer says. "

the manufacturer, who has noticed misinformation being propagated here, has corrected it, but has not disputed JB's tests...

give it a rest, already!

" This might logically have an effect on the ERX size, " and price...

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To clarify what James is saying a bit further, there currently may be some information in the website / manuals that may need to be corrected or further clarified, which may be leading to the overall confusion.

 

The Zaxcom website and manual state that the Zaxcom Nomad timecode generator has a clock accuracy of 1.54PPM, leading to 1 frame out every six hours:

post-8621-0-69022200-1406821432_thumb.pn

post-8621-0-81250200-1406821436_thumb.pn

 

I've found this to be an accurate reading. No issues so far.

 

Now, as James mentions, the ERX manual gives the exact same spec as the Nomad:

post-8621-0-32806900-1406821475_thumb.pn

 

Obviously, this may hold true as long as the ERX continues to receive a reference signal from the master clock via ZaxNet, however, on its own, this clock accuracy spec is probably higher, resulting in a shorter time before a 1 frame drift. (See John Blankenship's tests earlier in this same thread). This is where users are getting confused and perhaps better wording is needed.

 

As Jack and John and others have stated though, the drift is still pretty minimal, and for the correct applications they work flawlessly.

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Have you checked out the results of my tests above?  The average deviation was about a quarter frame after one hour and a half frame at the two hour mark.  That's well over "a couple of seconds" and pretty darn good "extended dropout" protection.

 

... but it's still more than advertised, as highlighted by other posts, Jose's above as an example. Is it a problem in real life? Apparently, for most here, it is not. But for some it is, especially if working under the wrong assumption.

 

 

The ZaxNet signal that is updating the TC is being sent from the sound bag/cart. The sound bag/cart is also where your audio is being recorded and being sent to camera from. 

So if the ERX goes that far out of range of the sound bag/cart for an "extended" period of time your audio will NOT be getting to the camera either and you will not have talent audio at the sound bag/cart either. So there is no real sync issue here.

(...)

How many people have ever had a sync issue with an ERX? I haven't.

 

OK, let's have a show of hands: I have.

In a situation (which happens less than frequently, but more than rarely) where my cart is parked rather far away from set. At setup, I checked the camera and thus saw the ERX was in range, and I usually walk around the set a bit, looking at the rx signal of the ERX to check for potential problems. But you know how it is, after the first setup the camera changes position, and goes out of range of my ERX. But I don't check the unit all the time, so sometimes I can have almost a half day without having proper sync on the ERX. There's enough drift to prompt a call from the assistant editor. Of course, it is also my fault for not checking the ERX all the time, but I am very much used to the set-and-forget dedicated sync boxes. This has really only happened to me once, actually, as I have now returned to my Ambient box on cart jobs.

 

For the people who are claiming false advertising or bitching about semantics

 

I wasn't so much bitching about false advertising, I think. What I meant was that Zaxcom had chosen a somewhat ambivalent wording and I ASSUMED that they didn't mind about people not understanding it correctly. This by the way, strictly refers to the old website which was active when I bought my ERXs. On the new site the wording is much better, although still a bit weird.

 

The clock accuracy is in the manual.

 

We have established by now, even with the help of the manufacturer, that it is not.

 

The ERX is a great device, I do want to make clear that I feel that way. Perhaps for me at least, I was getting into this like a new relationship, seeing everything that's great about and not seeing, perhaps even ignoring all that's not good about it, or what it simply isn't. I just wanted it to be this perfect thing, and it's always a bad awakening when the truth is revealed. And as in a new relationship, I just need to move beyond that point and still see everything that's good about it while accepting what's not good.

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"Assumption is the mother of all f*ckups" --- is that a real phrase? Probably not (and I won't use it again). But seriously, this whole ERX thread is really about not understanding the device and "assuming" all sorts of things.  Who is at fault? Is it Zaxcom with possibly un-clear description or explanation? Is it over-hopeful users who mistakenly hoped the ERX could replace their camera hop and their sync box? It is obviously a combination of all of these factors, and more, but at this point in the life of this thread I think we are all clear now on exactly what the ERX is and is not.

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"Howy has got back to me about the ERX. He says it has the same oscillator chip as the Deva, Nomad and Maxx so it should be good for 1 frame in 4 hours of unlocked operation."

 

This information is not correct. As I posted previously the ERX is different than the other products. 

 

As for the ERX time code accuracy specification it is the same as the Nomad as it is phase locked to the nomad, when used as directed. I can not imagine the specfication being any different as this is how the ERX has been designed to be used. As discussed it is not intended as a sync box but as a time code and audio distribution system. It can be and is used as a sync box with excellent results but that is not how it is promoted.

 

I want to thank JB for doing a very good test of the stand alone accuracy of the ERX. John was comparing it against another crystal based device, Of course like a man with 2 watches the exact time is always in question. 1 frame in three hours is most likely a good number. Some ERXs will be better some will be worse. As the typical RF dropout is very short the ERX stand alone accuracy does not come into play.

 

The advantages of the ERX (No jaming required, No calibration, No drift, light weight, long battery life, high quality audio reception, TC display, TC delay, frame rate transcoding, frame rate remote control and audio delay (Think thats most of them ;-)) are easy to see and understand.

 

The ERX is used on 100s of productions every day with perfect TC results. If there are any questions or concerns relating to specifications or features we are available everyday to answer questions. As the unit is not a sync box the accuracy of the internal oscillator is not specified as it is not used to determine the output time code when used as intended. Same as 100 other specifications that are not specified. 

 

The internal TC generator is only there to keep the time code flowing without interruption in the case of a dropout. I am very happy people use it as a sync box and its crystal accuracy has proven up to the task for the customers who want to use it in that way.

 

I am very happy that this thread had added to the understanding of our unique product as an important part of the Zaxnet system

 

Glenn 

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I totally agree with what Jeff said above, post #67. But since even at the manufacturer there seems to be confusion about the ERXs capabilities and the information contained within the manual (so all of Senators strategies fail) is plainly wrong, using the ERX in a way "not intended" is more than just an assumption.

When I read that the ERX would lose a frame in 6 hours, I felt confident that I wouldn't need to worry about maintaining an RF connection at all times. And no, in the technical specifications section of the menu, there is no mentioning that this clock accuracy is contingent upon Zaxnet sync with a Nomad. I don't even have a Nomad.

 

I'm glad too that this thread brought to light some unknown facts about the ERX. Wouldn't have been necessary though, if the manufacturer had put the correct info in the manual.

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"And no, in the technical specifications section of the menu, there is no mentioning that this clock accuracy is contingent upon Zaxnet sync with a Nomad. I don't even have a Nomad."

 

For proper intended usage the ERX does not require a Nomad recorder --- it does, however, require the wireless connection to Zaxnet (which could be Zaxnet from an IFB-100, IFB-200, QRX receiver with IFB option, etc.). This is my understanding (and I could be wrong as well). It is true that the stated descriptions by Zaxcom may have lacked clarity but I think we can all agree now, certainly after Glenn's very detailed post here, that we know exactly what the ERX is and is not. How people decide to use it is really up to the individual.

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For proper intended usage the ERX does not require a Nomad recorder --- it does, however, require the wireless connection to Zaxnet (which could be Zaxnet from an IFB-100, IFB-200, QRX receiver with IFB option, etc.). This is my understanding (and I could be wrong as well).

Jeff is correct - any unit that can transmit ZaxNet (not exclusively Nomad) will generate the same accurate TC for the ERX to receive. Im not sure how Nomad became the default ZaxNet transmitter in this thread but like Jeff posted an IFB100/200, Camera Link transmitter, QRX with IFB or Nomad will work. So as long as an ERX periodically updates its code from any one - or 2 (if you are using IFB voting) - of this units you will have no drift issues. 

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I was wrong about the ERX's oscillator. It is not the same as Nomad's. I would say then that the ERX should be good for 1 frame every 3 hours when NOT locked to an external source and when locked to a source it will not drift at all with respect to that source.

-howy

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Jack, I think Nomad became the default simply because I own one. And Howy responded relative to the chipset in the recorders - I'm not sure about the IFB and Camlink.

Many thanks to Glenn and Howy for the re-clarification.

As Jeff points out this now enables us to go forward with how to use our ERX confident in their limitations and plus points.

It might not be the worst idea in the world for the Zaxcom chaps to have a quick look at revising the details given in the manuals and online in case of further confusion from customers who may not see this thread. Some of us are a bit dense in the head, so lots of information is good! ; )

Thanks everyone!

Oh, and I still want a 'super ERX'! ; )

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