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Johnny Karlsson

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About Johnny Karlsson

  • Birthday March 15

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    http://www.johnnykarlsson.com

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    Los Angeles
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    Music, Food, Beer, Whiskey, Gear, Nature, Travel, Guitars, Technology, Fishing, Coffee, anything new... or old....
  • About
    Sound Mixer for TV, Commercials, Film, ENG, BTS, EPK etc. - Cart and/or Bag | | FCC Call Sign: WREL398 | | IATSE Local 695 Y-8 Boom Operator | | Dante Certification Level 2 | |
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  1. Keep in mind, if you’re comparing rates with a plumber: We quote on a guaranteed 10h day, and that means 8h of straight time + 2h at x1.5, so the plumber’s day rate would equal $80 x 11 = $880/day . However, a plumber can go around and do several jobs in a day, every day of the week, and charge extra for emergency jobs on weekends and holidays. We get booked per day, because every job is completely different, with a vastly different equipment package each time. So there is always prep etc. Our day rate stays the same regardless , because if you book me, it means you bought my services for the day. Mainly because we simply can’t book two jobs in one day. This is also why there is no such thing as a “half-day” rate. Ever. - Early on when I started out, I tried booking two jobs in one day, and that lead to some serious problems, because the nature of any production is that things change. And they always change on the day of, at the last moment. Another example - with branded content, most of the time I get called in at 7am with everyone else, but sometimes they shoot stills and slow motion video all day while I’m in standby mode - ready to jump in at any moment - then at the end of the day, I roll on a single “interview” or some one liners for 10 minutes. That doesn’t mean I “only worked for 10 minutes”.
  2. I'll add one more last thing: I do absolutely NOT recommend these for use in a Lectro Tx. I rolled on the last test and just spot checked it. There were loud pops intermittently towards the end of the file. Pop, then dead silence. Then it would come back on again. Then POP again. On and off a few times, so that would mean usable run-time is likely about 4h. After that it would be scary. I'm guessing this has to do with what Larry mentioned (the switching power supplies trying to figure out what to do with each other once the voltage starts dropping). So meh - sticking to my eneloops.
  3. You have that backwards. The transmitter draws more current at a lower voltage. And for real runtimes, there was no significant difference in the tests I did. Feel free to believe me or not, or run your own tests. I'm done with this topic. I just wanted to share my findings for anyone who cares. Not here to "win" an argument. Cheers !
  4. Same device (SMV) : yes. Different battery designs = same draw : no. Read Larry's post above. the SMV design allows it to run at full power, even when the AA has only 0.9V left, but in order to compensate for the low voltage, the transmitter draws "upwards of 0.6 Amps" at that voltage. Not sure what the current draw is at a full 1.5V (Larry?). And because this lithium AA stays at a constant 1.5V until it dies.... you get it.
  5. Haha, well good luck with that. A milliamp hour is a milliamp hour, yes, but in a device that draws 500 milliamps vs one that draws 900 milliamps will make a difference in how long the battery will last. In this case, we are comparing apples and oranges, because one of the batteries puts out a constant voltage until it dies, the other one gradually drops the voltage. What I thought might make a difference is the fact that the particular device I was testing the batteries with draws more current when it sees a lower voltage. That’s why I wanted to run the test to see what the actual real difference in runtime (if any) would be. I am not an electrician so it’s completely possible I’m confused, but anyway, I feel that I found out what I wanted to find out, and shared it here for those who care.
  6. Right, but... The theory I wanted explore was that the transmitter draws more current when the voltage is lower, and therefore would potentially drain the battery quicker. This Lithium AA: 3300mWh @ 1.5V = 2200mAh And NiMh: 2450mAh @ 1.2V = 2940mWh 2550mAh @ 1.2V = 3060mWh 2700mAh @ 1.2V = 3240mWh Of course, one thing that throws the formula off is, the NiMh doesn’t start at 1.2V fresh off the charger. It can be as high as 1.47V, then drops down to around 1.35V over the first 15 min or so. Then gradually drops further. So using the above calculation formulas does not give you the accurate comparison. That’s why running the tests in real life seemed to make more sense. And again the tests I did shows that the practical run-time is about equal.
  7. In theory, yes - but depends on which theory. Since the current draw is higher at 1.2V that it is at 1.5V. That’s what got me curious and made me want to test these to see what it meant in practice. And that does seem to even things out in terms of runtime. But no, I’m not planning to switch over to these. Now, if anyone could make a safe AA rechargeable that could run a DBSM for 6h30min, THAT would make me switch! (Not expecting that happening any time soon).
  8. 4:34 with the fresh eneloop pro at 50mw, so pretty much same.
  9. I trust Larry's theory. Based on that and what I see in my tests, I will conclude that these particular rechargeable Litihum AA batteries might be ok to use in single battery units, but not exactly ideal in dual battery units. 4:40 in a single battery unit at 50mw is usable for some applications. One advantage over NIMH is that these are lighter weight. Just for the heck of it, I will run a fresh eneloop Pro at 50 mw in a SMV tonight to compare the run time. Fred - I did not watch the receiver while running the test. I just set the SRC to AAT (timer), which stops when the transmitter shuts off. So, no I did not see the telemetry. Yup. +1
  10. Like I said, it does. See the above tests. It’s a well known fact. Not sure why you would have a hard time believing that.
  11. I believe they are in parallel. Otherwise it would double the voltage, right? And since you can run an SMQV with a single battery....
  12. Weirdly, with dual batteries, 50mw test, SMQV stopped at 4:40. (Equal to what I saw above with a single battery SMV at 50mw). Then put both of those batteries on charge - and one showed full almost right away. No idea why, but it appears the second battery did not kick in at all, and instead the SMQV shut down.
  13. And second run got 4h 37min on the SMV at 50mw. Which is 4 min less than yesterday. Seems usable for some stuff, and comparable to nimh. I believe the 7h 30min at 100mw with dual batteries in the SMQV is almost an hour less than I have seen with nimh. Running another dual battery test at 50mw now.
  14. Umm, just ran a single battery in the SMQV at 100mw, and only got 3h 41min.
  15. Hey Fred, yes - still testing, but first run yesterday gave me 4h 40min on the single battery SMV @ 50mw. 7h 30min on the dual battery SMQV @100mw. The paper that came with the batteries says performance should improve after the first few charge/re-charge cycles. Some reviews on Amazon say they had overheating and melting problems - BUT from what I can read there, it seems like people didn't read the instructions, which clearly says to only charge these via the micro USB port on the battery itself. The set came with a USB-A cable that splits out to 4 micro USB, so one USB port can charge 4x batteries. At least some of the reviews seemed to indicate that they had tried charging with a regular battery charger...
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