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About LarryF

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    Hero Member
  • Birthday 12/11/1943

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  • Location
    Rio Rancho, New Mexico
  • Interests
    Classical music, fast cars and Maine Coon cats
  • About
    I have been chief janitor at Lectrosonics for 40+ years.
  • Interested in Sound for Picture

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  1. We update whenever we think a project is finished under the well established rule that the last 10% of a project takes 90% of the time and the other even older rule known as Hofsteader's rule that a project takes twice as long as your best estimate even when taking Hofsteader's rule into account. The other rule, not formalized, is that no matter how much you test and beta test, your suffering users will find bugs a few days after release. Best Regards, Larry Fisher
  2. Hi Matthew, One other factor that comes into play is that the intermod products are always at lower levels than the carriers of the two off frequency offending transmitters. This means that the desired third carrier is almost guaranteed to be much stronger at the receiver than the intermod from the two offending carriers. Remember it takes at least three transmitters to create a problem. You must have two offending transmitters interfering with a third desired transmitter signal. If all three transmitters are at roughly the same distances from the receiver, the desired signal will overcome the relatively weak generated intermod. When intermod does become a concern, is when the offending transmitters are close to the receiver (or each other) and the desired transmitter is at a long distance or the desired signal is momentarily weak due to a drop out, i.e., multipath (null). As I said, the Lectro program is a worry wart. Best Regards, Larry Fisher
  3. Hi Matthew, From what you posted, you've got a good grasp on what the two different programs are doing. The Lectrosonics' program is very conservative. As it said, the carriers are outside the passband of the receiver and probably won't cause much intermod at the receiver, particularly if the talent is more than a few feet away from the receiver antennas. The receiver front end filters will reduce the out of band carriers while leaving the desired signal at full strength. The "offending" transmitters output stages, however, don't have that filtering and if very close to one another (a foot or so) may generate an intermod product while they are physically close together. If the transmitters are always farther than that apart (not in a bag) or the talent transmitters are not very near each other, the intermod will not be a problem. If you have weak amplifiers in the multicouplers and the talent gets close to the antennas simultaneously (less than 10 feet), you might have a problem. With robust amps in the distribution system (Lectros) it probably isn't a problem. So the Lectro program is telling you, don't worry about receiver intermod but keep an eye on the transmitters being physically together (in a bag) or close to antennas tied to distribution amps. The Shure program is saying, Lectro is a bunch of worry warts, get on with the show. Best Regards, Larry Fisher
  4. Theoretically the shorter wavelengths should provide a little less range. That is more than offset by the fact that the RF background noise level at 941 frequencies is so much lower than the noise in the 470 to 600 MHz bands. So, in 99 cases out of 102, the range is better in the 941 band. Best Regards, Larry Fisher
  5. Those units did not provide bias power at the antenna input. Best Regards, Larry Fisher
  6. 100 MHz is 4 full blocks not 2. Have edited. LEF
  7. The bandwidth for a 2:1 SWR (Standing Wave Ratio) is generally considered a good operating bandwidth for an antenna. The 2:1 SWR of the SNA600 is +- 50 MHz or 100 MHz bandwidth or 4 full Lectro blocks. The 3 db down points are +- 75 MHz or 150 MHz bandwidth or 6 blocks. The frequency markings for the arms of the dipole are for centering the frequency range but don't exclude frequencies that are within a block or two of the center. The design was deliberately made wideband with the fat dipole arms. You can see that the real world operating frequencies described by the posters above (thanks) fall within these criteria. Best Regards, Larry Fisher
  8. +5 is the best setup. Best Regards, Larry Fisher
  9. Hi Brian, The new firmware resolved the hybrid emulation problems in general that we knew about. The fact that it made no difference for you and the fact that other model transmitters (SM) don't have the problem points to the HM as a major part of the problem. The circuity between the SM and HM is very similar which makes this a puzzler. Best Regards, Larry Fisher
  10. RG58 is fine. You will have a decibel or less of loss. Best Regards, Larry Fisher
  11. Removing some strands is the correct solution. It won't hurt a thing over the short distances you are working with, i.e., much, much less than a wavelength. LEF The SMA will be properly grounded when it is mechanically screwed down to the case. The case is the ground plane for the whip antenna and the case is solidly grounded to the PC board. You only need the one connection from the center pin of the SMA to the antenna input on the board. It sounds like the antenna input is somehow shorted to the ground of the system. You might see if one of the units measures differently with an Ohm meter (multimeter). However, it is possible that the normal antenna input is grounded at DC though with an inductor to ground. Look for small differences. Best Regards, Larry Fisher
  12. We've always let all units run until the battery is "dead", under the philosophy that a few extra minutes may save a very expensive shoot. The user can always change batteries earlier, which I recommend. Good NP-50's have protection circuits that shut the battery down before the battery is damaged. There is no reason for us to second guess the situation and shut the units down earlier. Best Regards, Larry Fisher
  13. https://www.lectrosonics.com/Digital-Wireless/category/d2-system.html Not really a "Venue 3" but does everything a Venue 3 would do including new abilities at lower cost per channel. It makes a Venue 3 redundant. Best Regards, Larry Fisher
  14. Hi Nathan, I can't find them on Amazon. Maybe the US site doesn't list them. (??) International shipping problems across the pond maybe. Best Regards, Larry Fisher
  15. Not to blow our horn but just some battery facts. 1. The Lectro batteries are OEM'd directly from Panasonic to Lectro and then shipped to our dealers. Fake batteries from us or a dealer should never be a problem. As far as I know, we have not had a substandard battery in the field. 2. The Lectro batteries were issued battery safety certificates from CE and UL. We paid for these and we have them on file. There are a lot of crappy batteries in the marketplace. Not only are their capacities pipe dreams of their marketing departments but the safety markings are usually faked. A full battery safety test is about $10,000 and the ink for fake markings is less than a penny. Best Regards, Larry Fisher
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