Emory Murchison Posted February 24, 2012 Report Share Posted February 24, 2012 So I went and bought a QRX100 to use as a wireless camera link. I powered it from Sony NP-F battery and an Ikan sled. The very first day shooting exterior in cold weather the unit stopped passing audio after about 3 hours. The lights and display were still on but the QRX was unresponsive. Unplugging and replugging the battery fixed that, but now I was nervous. The same problem got worse all day and by the afternoon I went back to feeding the camera by cable which was difficult because we were downhill skiing! After the day was done I got back to the hotel to try and do some troubleshooting only to find that my brand new QRX would not even power up. Totally dead. Now its full on panic time. I have three more days of shooting documentary style in and around ski resorts in Quebec and no more wireless link. Luckily the friendly folks at Sonotechnique montreal happened to have an RX900 demo in the same block that I was able to rent to tide me over. I have two questions: 1. Has anyone else experienced anything like this? and 2. who is going to pay for renting the RX900? slightly miffed, emory Quote Link to comment Share on other sites More sharing options...
Jack Norflus Posted February 24, 2012 Report Share Posted February 24, 2012 Perhaps as the day continued the power level in your battery dropped - and since it was cold the battery wasn't able to maintain / supply enough power to properly power the QRX. What are you using to power your QRX for your troubleshooting? Is it the same battery and or the same sled? Do you have another source of power to try? Quote Link to comment Share on other sites More sharing options...
Thomas Popp Posted February 24, 2012 Report Share Posted February 24, 2012 I agree - it sounds like a power issue. The QRX100 draws quite a bit of power. Are you able to power it off of the camera? Quote Link to comment Share on other sites More sharing options...
JDirckze Posted February 24, 2012 Report Share Posted February 24, 2012 Yes, same thing has happened to me too. IIRC I was powering my QRX off the camera battery and as the camera battery level got lower my QRX would not power up when the cameraman cycled power. I'm stretching my memory here but I think there is a power saver option there that may have some significance, and I believe a firmware update sorted out that issue... As the Senator would say, "HAT" Quote Link to comment Share on other sites More sharing options...
Jack Norflus Posted February 24, 2012 Report Share Posted February 24, 2012 I'm stretching my memory here but I think there is a power saver option there that may have some significance Power saver will reduce power consumption when the QRX isn't receiving any audio - but when it is receiving audio it will automatically return to full power. Quote Link to comment Share on other sites More sharing options...
Jim Gilchrist Posted February 24, 2012 Report Share Posted February 24, 2012 Hi, Emory You might want to join the Zaxcom User's Group in addition to posting here. Best regards, Jim Quote Link to comment Share on other sites More sharing options...
Emory Murchison Posted February 24, 2012 Author Report Share Posted February 24, 2012 I have tried both my fully charged NP-F batteries, as well as powering from an NP-1 and BDS. Still nothing. I'm sending it back to Trew audio today. Quote Link to comment Share on other sites More sharing options...
glenn Posted February 24, 2012 Report Share Posted February 24, 2012 The QRX100 is designed for 12V power. If I am correct you were working with a 7.2V battery. The unit will not work under this condition. We will check it out when it gets back but a 12 Volt battery must be used to run the unit. Glenn Quote Link to comment Share on other sites More sharing options...
Twade Posted February 24, 2012 Report Share Posted February 24, 2012 The Ikan has a stepped up output to 12v. Quote Link to comment Share on other sites More sharing options...
Jack Norflus Posted February 24, 2012 Report Share Posted February 24, 2012 The Ikan has a stepped up output to 12v. which might explain why Emory was able to get three hours use before he started having issues. Quote Link to comment Share on other sites More sharing options...
rich Posted February 24, 2012 Report Share Posted February 24, 2012 do you have access to an un unregulated power supply that can feed more than 12 v to the receiver? i have found that with my qrx100 with ifb board, if i power it from my hawkwoods regulated np1 shoe, the unit will not power up if i switch it off using the on/off switch the qrx, (though switching off from the np1 shoe's switch is fine), it will not power up until the qrx sees more than 12v - or at least i power it directly from a lithium battery. Quote Link to comment Share on other sites More sharing options...
Twade Posted February 24, 2012 Report Share Posted February 24, 2012 which might explain why Emory was able to get three hours use before he started having issues. but not why after switching to a new battery or changing over to np1's he continued to have problems. Quote Link to comment Share on other sites More sharing options...
glenn Posted February 24, 2012 Report Share Posted February 24, 2012 It is very possible that the 7.2V to 12V converter would not be able to run the QRX when the 7.2V batt was low. QRX100 with QIFB return draws 350ma at 12V. It would draw about 500ma or more from the 7.2V battery. Start up current could be as high as 1 amp. Glenn Quote Link to comment Share on other sites More sharing options...
Derek Bruce Posted February 25, 2012 Report Share Posted February 25, 2012 Agree with everyone else - most likely a power problem, probably made worse by the cold temperatures. As with other users I have had issues powering the QRX100 from 12 volt regulated adapters such as the Hawkwoods range. Chances are the step up voltage adapter has a regulator in it which isn't providing enough power to switch on the QRX - try using an unregulated power supply if you have one. You could also try turning the side LEDs and LCD brightness off. As for the cold, had my QRX running all day at minus twenty degrees centigrade with no problems. Quote Link to comment Share on other sites More sharing options...
Boomboom Posted February 25, 2012 Report Share Posted February 25, 2012 You guys have a "receipe" for powering the QRX alone, like for shootings with an EX-3 ? Quote Link to comment Share on other sites More sharing options...
MatthewFreedAudio Posted February 25, 2012 Report Share Posted February 25, 2012 I use an NP1 with a Frezzi cup to power my receivers when they can't be powered directly from the camera. Seems to always work. www.matthewfreed.com Production Sound Mixing for TV, Films, and Commercials Quote Link to comment Share on other sites More sharing options...
Emory Murchison Posted February 25, 2012 Author Report Share Posted February 25, 2012 so i agree it did seem like i had a low battery which might explain the very odd behaviour of freezing and needing to be unplugged to power down. I also agree that maybe with the 12V regulator on a 7.2V battery it might run out of available amps before the QRX knows the battery is dead. maybe somebody from zaxcom or somebody who knows a bit more about how the powering electronics of the QRX are built can give an answer as to whether regulated sources are for sure a no go with this unit? i don't want to get a replacement for my now completely bricked QRX only to have the same thing happen because of my battery choices. or maybe i have no choice but to go out and invest in a whole new battery system for the qrx on top of paying for the emergency rental replacement! it seems my QRX system is getting more expensive by the day! cheers, emory Quote Link to comment Share on other sites More sharing options...
Jack Norflus Posted February 25, 2012 Report Share Posted February 25, 2012 l You guys have a "receipe" for powering the QRX alone, like for shootings with an EX-3 ? I use an NP1 with this: http://www.bhphotovideo.com/c/product/133902-REG/IDX_NH_100_NH_100_Single_NP_1_Holder.html Quote Link to comment Share on other sites More sharing options...
Jeff Wexler Posted February 25, 2012 Report Share Posted February 25, 2012 I also agree that maybe with the 12V regulator on a 7.2V battery it might run out of available amps before the QRX knows the battery is dead. maybe somebody from zaxcom or somebody who knows a bit more about how the powering electronics of the QRX are built can give an answer as to whether regulated sources are for sure a no go with this unit? emory I'm not an expert on this powering issue, but I believe the problem is that if you use any power source that is regulated and designed to only deliver 12 vdc, it is the regulation circuit (or regulator, dc to dc converter) that makes it difficult to actually determine the current rating of the battery supply or what the regulator is drawing off the battery. With a standalone fully charged unregulated battery of known chemistry and specification, it will be easy to calculate its performance. It may well be that the QRX receiver is quite demanding in its powering requirements (it is doing a whole lot of work compared to an ordinary and common receiver), but it shouldn't be too difficult to get the spec from Zaxcom and then provide the power and current it requires. Quote Link to comment Share on other sites More sharing options...
soundslikejustin Posted February 25, 2012 Report Share Posted February 25, 2012 Glenn gave us the spec above. The QRX pulls 300ma at 12 volts. With nothing else on in the bag, I can see this is right. My RM reads 0.32 amps. The issue here is the switching power supply in the battery supply. .32 amps at 12v is 3.84watts. Which is .52amps at 7.4 volts. This is assuming a perfect voltage conversion (no loss) which we know doesn't/can't happen. So say the converter stepping up the voltage has an efficiency of 82%. That means you're now pulling .63 amps at 7.4v. If the startup current could be as high as 1 amp @ 12v, that's 1.97amps at 7.4v, which should be ok for any decent battery, but may be too much for the switching power supply. If my maths is off, please feel free to correct me. When the battery gets low - 6v is the LVC for these batteries - now you're looking at nearly 2.5 amps to start the QRX. Quote Link to comment Share on other sites More sharing options...
Jack Norflus Posted February 25, 2012 Report Share Posted February 25, 2012 .32 amps at 12v is 3.84watts. Which is .52amps at 7.4 volts. This is assuming a perfect voltage conversion (no loss) which we know doesn't/can't happen. So say the converter stepping up the voltage has an efficiency of 82%. That means you're now pulling .63 amps at 7.4v. If the startup current could be as high as 1 amp @ 12v, that's 1.97amps at 7.4v, which should be ok for any decent battery, but may be too much for the switching power supply. If my maths is off, please feel free to correct me. Holy Crap! That makes my head hurt. Quote Link to comment Share on other sites More sharing options...
soundslikejustin Posted February 25, 2012 Report Share Posted February 25, 2012 Holy Crap! That makes my head hurt. Sorry Jack Here's a picture of a puppy for you. Quote Link to comment Share on other sites More sharing options...
John Blankenship Posted February 25, 2012 Report Share Posted February 25, 2012 ... I have two questions: 1. Has anyone else experienced anything like this? and 2. who is going to pay for renting the RX900? I'm going to try to be slightly gentle since you're holding an infant. The answer to your second question is: "Whoever it was that talked you into going out on the job without a backup, ESPECIALLY, with a new piece of gear!" That's who should pay for the backup. If it was you, then the rental was the price you paid for a valuable lesson that can last you your entire career. As far as what battery supply will work and whether a regulated supply would work, it depends upon further information. What supply works well with any given device has to do with both voltage and current requirements of the device and the voltage and current capabilities of the power supply. It isn't an issue of whether it's regulated or not, it's an issue of having the right supply for the job at hand. A general bit of advice is, that when it comes to powering, never try to just barely meet a device's needs. You've seen the unhappiness that causes. If you're dead-set on using Sony 7.2 volt batteries, here's a device that might work for you: http://www.hawkwoods...-sqn4s It has four switched Hirose sockets and a Hirose male-ended cable (for powering a mixer, for instance). It uses two Sony batteries coupled in series and has a voltage-regulated output. I haven't used it and I'm certainly not guaranteeing it, but it seems purpose built. A friend, who has a large cache of Sony batteries, said that Sound Devices recommended it for powering his mixer rig. He's had problems finding them in the U.S., and thinks he'll probably need to order one from the UK. If anyone finds them stateside, please let me know and I'll pass it on to him. Quote Link to comment Share on other sites More sharing options...
Emory Murchison Posted February 25, 2012 Author Report Share Posted February 25, 2012 yeah, question two was a little silly. sorry about that. of course i had a backup, it was the cable. production never stopped. because it was a new kit, i can't see having a backup for everything on hand. after all the rental fee is for one kit, not two. that being said, i always go out backed up and unless i get struck by lightning while carrying all my gear, sound will get recorded. so what i'm getting from this discussion is that because of the 12V step up, the QRX is going to be finicky as soon as my battery goes down just a bit. so unless i get the biggest sony batteries rated at 9000mAh I can basically forget it. but using a battery that big i might as well hook up an NP-1 and the camera folks will just have to live with it. Quote Link to comment Share on other sites More sharing options...
soundslikejustin Posted February 25, 2012 Report Share Posted February 25, 2012 (edited) yeah, question two was a little silly. sorry about that. of course i had a backup, it was the cable. production never stopped. because it was a new kit, i can't see having a backup for everything on hand. after all the rental fee is for one kit, not two. that being said, i always go out backed up and unless i get struck by lightning while carrying all my gear, sound will get recorded. so what i'm getting from this discussion is that because of the 12V step up, the QRX is going to be finicky as soon as my battery goes down just a bit. so unless i get the biggest sony batteries rated at 9000mAh I can basically forget it. but using a battery that big i might as well hook up an NP-1 and the camera folks will just have to live with it. No, you can keep using the 7.4v batteries. Just use the Hawk-Woods SQN4s that John Blankenship posted above, which combines the two 7.4v into 14.8v. Now you're stepping down, and using LESS amps from the battery than the QRX requires because your voltage is higher. Edit: Sorry, I forgot that you're attaching the QRX to a camera. In that case, perhaps consider one of these: http://www.all-battery.com/li-ion18650148v2200mahrechargeablebatterypackwithpcbprotection.aspx Runs my QRX for about 5 hours. Edited February 25, 2012 by soundslikejustin Quote Link to comment Share on other sites More sharing options...
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