Emory Murchison Posted April 24, 2012 Report Share Posted April 24, 2012 I am unable to get the QRX 100 to Jam timecode. I've read everything i can find including the 225+ replies to the questions for glenn thread. IFB audio from the QRX to my TRX900 works The timecode cable (purchased from TREW) has signal going to the ring, I checked. My timecode source will jam perfectly when plugged into the TRX (signal to tip). I even tried making up another timecode input cable for the QRX with no luck. The QRX has software version 212 and IFB software 1.44 In the IFB extended menu I can't find anywhere to set the timecode source so I'm assuming that when IFB is in TX mode the timecode source automatically is set to the rear connector. The other strange behaviour i noticed is in the IFB menu I can only manually jam it to a set value once after powering up. after that when I A/B over to the JAM it immediately jumps to the TC Jammed screen without changing the TC value. I'm not sure what settings in the QRX could affect its ability to Jam from external timecode and I'm getting dizzy from going through all the menus. On a side note, thanks to all the replies and help from my QRX Fail post. The verdict from Zaxcom was a blown 3V regulator which they replaced. Any help with the TC JAM issue would be appreciated! -emory Quote Link to comment Share on other sites More sharing options...
Tom Visser Posted April 24, 2012 Report Share Posted April 24, 2012 You have set timecode jam mode to auto-load or auto-jam? This is in the IFB EXT MENU and not the IFB HOME MENU. Quote Link to comment Share on other sites More sharing options...
Emory Murchison Posted April 24, 2012 Author Report Share Posted April 24, 2012 I set the jam mode to auto-jam and i also tried Manual(off) i also for fun tried putting the QRX IFB in RX mode, then changed my TRX IFB to TX mode and the timecode jammed right away. interesting but kinda useless. Quote Link to comment Share on other sites More sharing options...
Tom Visser Posted April 24, 2012 Report Share Posted April 24, 2012 Is the USE TIMECODE FROM TRX900 set to OFF in the EXTENDED MENU? Quote Link to comment Share on other sites More sharing options...
Derek H Posted April 24, 2012 Report Share Posted April 24, 2012 Yeah it can be a pain in the a... it doesn't help that manual is incomplete and headache inducing. Try to jam from a different source to confirm that it's not a bad TC source. I haven't been able to jam from the c300 Quote Link to comment Share on other sites More sharing options...
Emory Murchison Posted April 24, 2012 Author Report Share Posted April 24, 2012 I still have to try a different TC source. But my test TC source (Pro Tools) does jam the TRX and everything else just fine. that's to bad about the c300 I'm shooting with that camera on Friday! Quote Link to comment Share on other sites More sharing options...
Derek H Posted April 24, 2012 Report Share Posted April 24, 2012 Let me know if your QRX takes a jam from it. I'm wondering if it just doesn't like it because it's on the weak side. Perhaps the c300 is slightly under spec than it's 1 V p-p rating. Quote Link to comment Share on other sites More sharing options...
Emory Murchison Posted April 27, 2012 Author Report Share Posted April 27, 2012 Derek, no luck on the c300 jam. i did get it to jam from a sony f3 though so my unit isn't totally broken... Quote Link to comment Share on other sites More sharing options...
Jack Norflus Posted April 27, 2012 Report Share Posted April 27, 2012 I've heard of other people having issues jamming from the c300. Quote Link to comment Share on other sites More sharing options...
Derek H Posted April 27, 2012 Report Share Posted April 27, 2012 That would be me! Others too probably. I've been in contact with Howy trying to figure it out. Quote Link to comment Share on other sites More sharing options...
Emory Murchison Posted May 17, 2012 Author Report Share Posted May 17, 2012 This i copy pasted from my post at the zaxcom user forum: i am having the same problem. i can't jam the qrx from a Canon C300 (I've tried 2 different cameras). so i did some tests. I recorded tc out from the camera and from the qrx tc out. here's a picture from PooTools: the level from the C300 is higher than the level out of the QRX (set to 1V) but it looks like the QRX signal has more HF content or is that distortion? I'm not sure how to interpret it. maybe someone who knows what a SMPTE LTC signal is supposed to look like could say. I also tried to jam the QRX from the signals I recorded and surprise surprise it worked perfectly. The signal I recorded from the QRX own output switched the QRX back and forth from JAM to TX in the IFB menu. But when I moved the fader up a bit it went to a solid jam. So I did the same test with the recorded C300 signal and it behaved the exact same way. I even compared the output level meter of the two signals at the level where the QRX lost JAM and it was virtually the same. so i'm not sure what the conclusion is but this seems confusing to me. it looks like the QRX only doesn't jam in the situation where it is plugged directly into the camera Quote Link to comment Share on other sites More sharing options...
John Blankenship Posted May 17, 2012 Report Share Posted May 17, 2012 Perfect time code should be a square wave with straight verticals and straight horizontals -- just like the name sounds. The upper waveform is quite rounded for a square wave. The bottom waveform has overshoot. It appears that time code waveforms with overshoot read much better than waveforms that have a secret desire to be sine waves. The diagram at the right of the following page shows a sine waveform, a square waveform, a triangle waveform, and a sawtooth waveform, respectively: http://en.wikipedia....wiki/Squarewave The width of a waveform can vary, however, so in your upper example, they shouldn't all be truly square, but should ideally have straight (not sloping) vertical lines and straight (not rounded) horizontal lines. Do you have a Denecke box that will reshape timecode? If so, try running the C300 output through that. Quote Link to comment Share on other sites More sharing options...
Emory Murchison Posted May 17, 2012 Author Report Share Posted May 17, 2012 I could imagine that the slightly off square wave might create problems but why does it work when i record then play it back from my protools? but maybe i made some kind of mistake in my troubleshooting... i'm not sure the camera man would be happy if i plonked the qrx + battery + denecke onto his little semipro camera. Derek, have you figured this out yet? Quote Link to comment Share on other sites More sharing options...
John Blankenship Posted May 17, 2012 Report Share Posted May 17, 2012 ... i'm not sure the camera man would be happy if i plonked the qrx + battery + denecke onto his little semipro camera. ... You could remind him that's what professional cameras are for. But, he wouldn't like you any more. Quote Link to comment Share on other sites More sharing options...
John Blankenship Posted May 17, 2012 Report Share Posted May 17, 2012 I've found with time code problems before, it can be a combination of how clean the waveform is and feeding the right level. Quote Link to comment Share on other sites More sharing options...
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