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LarryF

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Everything posted by LarryF

  1. Article in "Wired" magazine about 4 years too late. https://www.wired.com/story/wireless-mics-radio-frequencies-fcc-saga/ Best Regards, Larry Fisher
  2. LarryF

    So, antenna issues with 941

    Several points about the antenna: 1. It has 3 dB of forward gain compared to a regular dipole or whip, a small amount of rejection at the rear and is broadband due to the angled reflector and fat arms. 2. The silver metal flange at the rear is for permanent mounting and can be bent at the various notches to handle any mounting surface. 3. There is a Lectro stand mounting kit but right now I'm getting a 404 error. You can see it on the data sheet though: https://www.lectrosonics.com/US/All-Accessories/product/pca900-2.html#data-sheet 4. Please note that this antenna says "VERT" rather than "UP". (See we learn, we're just slow.) Best Regards, Larry Fisher
  3. LarryF

    Microdot to Lectro TA5 failure

    Hi Dalton, And the terrible thing is, if you forget to mark the lines in the heat of battle, you have to start all over again. Best Larry F
  4. LarryF

    Microdot to Lectro TA5 failure

    Dalton and Rado, Increased losses from connecting and disconnecting RF connectors is pretty much a myth. I would get a very tiny magic marker and mark a tiny line on the side of the SMA or BNC connector. After I counted 10,000 lines, I would put on a brand new connector. Best Regards, Larry Fisher
  5. LarryF

    Lectro SMV battery drain

    Hi Mirror, I use a toothpick to pick up a little paste from the container and use that to apply it to the screw thread. However, I will check with the factory and make sure we are still putting the same (correct) amount in the vial. It probably wouldn't break us to add a bit more. Best Regards, Larry Fisher
  6. LarryF

    New wireless TX deviation rules October '18

    Thanks for the timelime, Gordon. LEF
  7. LarryF

    Lectro SMV battery drain

    Good point Dean. Also, Wright's Silver Cream is the best and only recommended cleaner. LEF
  8. LarryF

    New wireless TX deviation rules October '18

    Correct. LEF
  9. LarryF

    Lectro SMV battery drain

    Hi Mirror, You are using too much. One vial will do 10 applications, so divide the contents accordingly. It only takes a speck to make a very thin layer. It is sufficient to clean the threads before application with a dry microfiber cloth, rubbing the male and female threads until no black residue shows up on a clean section of the microfiber towel. Then apply the 10% speck to the leading male thread. Each future battery insertion will spread the grease up and down the threads. Below is the grease that we use. There is a lot of thermal grease called silver paste on the market that contains no silver but is just silver colored. Some is called silver paste and is not electrically conductive at all. Some has carbon in it and is moderately conductive. Some is a combination of carbon and silver, if you are lucky. As usual, if it is cheap, it is probably crap that is colored silver. The 100% good stuff is below, Chemtronics CW7100: http://farnell.com//datasheets/1795243.pdf https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=CW7100 Best Regards, Larry Fisher
  10. LarryF

    New wireless TX deviation rules October '18

    As Gordon posted above: "Basically, any transmitters manufactured or sold after October 18 must not only conform with the new regulations...." Transmitters have a legal cutoff, not receivers. Best Regards, Larry Fisher
  11. LarryF

    New wireless TX deviation rules October '18

    Again, if you need re-blocking, get an appointment now. August is already filled up and we don't know what will happen in September as far as having available re-blocking slots. This is all new to us too. We've had to split our service techs into regular service people and the re-blocking crew, so re-blocking doesn't totally get in the way of repairs (much). The only good thing on the horizon is that after mid-October, the wireless world will be stable for some years, the re-blocking crew can get back to regular repairs and our service turn around time will drop back to classical Lectro levels. Best Regards, Larry Fisher
  12. LarryF

    New wireless TX deviation rules October '18

    "Kind of good for the manufacturers I guess." Actually it is pretty miserable. All current transmitters have to be re-tested and re-certified under the new standards and each frequency block is treated as a separate transmitter. This is not cheap, running into the hundreds of thousands of dollars. This is coming from our pockets now but you know where it comes from ultimately. Also, if you have older Lectro units you are intending to reblock, get an appointment NOW (caps deliberate to indicate screaming) because after September 30, Lectro will not be able (no longer legal) to reblock the previous generation units. August is already booked for reblocks and September may fill up also. If you are gnashing your teeth, remember, all this is due to big government and big money. Best Regards, Larry Fisher
  13. Indeed, the UCR200 was a pretty decent hand warmer. We had good use reports from Siberia; not so good from Panama. The UCR205 and higher 2xx numbers used switching power supplies and, shall we say, more careful design to reduce the current draw by half and the power draw at higher input voltages by even more. Best Regards, Larry Fisher
  14. Very selective receiver with narrow front end using helical resonators. Selective IF using crystal filters. The most RF selective, bullet proof, single frequency receiver we ever made but note the word "single" frequency. If somebody is on the same frequency, you can not change to a different frequency. Also, the local oscillator crystal is not as shock proof as newer frequency agile units so dropping these on concrete is chancy. The repair would be equal to the used cost (or more) of these units. There are some users running them as backup units. Of course there are still a lot of 185 VHF systems still in operation. Best Regards, Larry Fisher
  15. The current conversion or update price to change an SRa to an SRb is $250 in the US. That price will be good until 31 July 2013. It will increase 50% to $375 after 31 July 2013. At the end of the year, we will drop the conversion "deal". Current cost for a block change is $752.38 and the SRb conversion uses exactly the same parts and requires the same alignment. So, at the end of the year the conversion may get pricey. Note that at $375, it is still half price. If you can't get a unit in before 31 July, simply make an appointment before then for a conversion before 30 Sept 2013. This gives you 50+ days to decide to rob the piggy bank and 111 days to find a break in your schedule. If you have a firm appointment, the crew is good about turning the units around for a specific return date. In the past few months, we have have done a thousand conversions in bulk. That is slowing down and in a few months it will start becoming similar to a regular repair. Hence the pricing change. Best Regards, Larry Fisher Lectrosonics
  16. LarryF

    "Like" button

    Ha!
  17. LarryF

    DIY sma antenna

    You would be pretty close, particularly on the mid blocks. All whip antennas are matched to the case (a very oddly shaped ground plane) of the particular device. It probably doesn't make a lot of difference, but if when Lectro is making thousands of them, we might as well measure the antenna and device together and get the right length. I recommend you send an email to service@lectrosonics.com and ask for the correct length for your particular block 25 devices. They should give you an answer pretty quickly. Let me know if you don't get an answer in a few days, though I can't imagine it. Best Regards, Larry Fisher
  18. LarryF

    Lectrosonics issues

    The best reason for running full tilt, is that ground loops, less than perfect power supply issues, and any induced noises in the cable between the Lectro receiver and the mixer are greatly suppressed. As you said, "why not". The receiver is running full tilt anyway (and perfectly happy doing it). The only reason I ever heard for running at mic level out, that made any sense, was that the operator could switch from wireless to a hard wired mic cable at the input of the mixer without radical gain changes. Or that the device being fed by the receiver only had mic level inputs. Finally, let's play with some numbers: If you have the world's best mic preamp with a noise floor of -132 dBm and you run the Lectro or other receiver at -50 dBm out max, the best signal to noise ratio you can have is an 82 dB SNR. Pretty good but not the best. Considering that some folks dial in too much headroom (YMMV) for another 20 dB of lost signal and also that the gain staging in the mixer is rarely perfect, your best SNR is now less than 62 dB. Who needs a fancy recorder when a refurbished Nagra will work as well. Best Regards, Larry Fisher
  19. LarryF

    DIY sma antenna

    Also Chris, tin (presolder) that steel wire before you try soldering it to the center pin. The steel wire will take much longer to solder and you don't want to destroy the insulation around the pin. Another also: clean all the oil off that wire if there is any and you might use a mild soldering flux on just the wire before you tin it. Best Regards, Larry Fisher
  20. LarryF

    Lectrosonics issues

    The receiver is alway running at a +5 setting internally anyway. At 0 dB, you are putting 5 dB of attenuation after the receiver output stage. That's fine of course, but if you need the slightest reason for +5 sometime, there is absolutely no reason not to run it there. Best Regards, Larry Fisher Try setting the transmitter gain according to the manual, if you aren't already. That is, turn up the transmitter gain until the talent is hitting the limiting indicator on the receiver occasionally. The limiting indicator on all the Lectro receivers lie a little in that they indicate the onset of limiting about 4 dB or so before it occurs. And, it isn't clipping or distortion, it is soft limiting. Hopefully, doing this will show you the direction to head, in order to reduce the tics. Best Regards, Larry Fisher
  21. LarryF

    DIY sma antenna

    Hi Chris, The 50 Ohms is just the impedance of the whip antenna resonating in free space. The fact that it has to be resonate to match to the 50 Ohms of your antenna input or output is why the resonate length is somewhat critical. Space itself is 377 Ohms as I (and Google) remember. The antenna resonates in order to match that 377 Ohms to 50 Ohms. The material of the wire has almost nothing to do with it since the any 6" wire's resistance is probably less than a tenth of an Ohm. In sum, the wire could be silver or lead with the same performance. Price wise, some people think our antennas are made from gold. Best Regards, Larry Fisher
  22. LarryF

    DIY sma antenna

    That should be very similar to the steel cable Lectro uses for antennas, so that wire should be a good choice Best Regards, Larry Fisher.
  23. LarryF

    You think WE'VE got sync problems?

    Not to be a PITA but 7.8 ms is 128 Hz, easily hearable. I think it's 7.8 Hz or a pulse every 128 ms. OK, now I've gotten my Sunday PITA cravings out of the way. Best Regards, Larry Fisher
  24. LarryF

    Ultrasound, IoT and wireless

    Ultrasound (ultrasonics) is well known to create overload in the audio compander section of the audio processing system of some wireless. Particularly those that have a great deal of pre-emphasis wrapped around multiple sections of the audio circuits. This well known (but occasionally surprising) artifact of some popular wireless can be prevented by not using pre-emphasis (or only a moderate amount) in the audio and by sharp roll off of frequencies above 20 kHz. Best Regards, Larry Fisher
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