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Matthew Steel

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About Matthew Steel

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    Live sound and recording for higher education

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  1. Not sure if this is Larry's tumbleweed, but there is an FCC certification for the DPR: * Tunes anywhere in TV channels 14-36 - i.e. any legal TV frequencies. * Size and weight of the HMa so probably plug-on. * 50mw and 25mw power settings. Also there is a unit called the DBu that is digital encrypted wireless in the LT form factor. It might already be released because it was certified in 2017. It doesn't seem well advertised but the manual is out there if you search.
  2. Just for the record, I just paced it off and we're more in the range of 110-170 feet. Considerably closer than my mental estimate.
  3. We have a couple of things going for us as far as channel count - we are indoors, in a building that uses a wire mesh as a base for plaster. Also, we are in a small/medium city and so the TV stations are not totally crammed in. We routinely operate at 200-250 feet between transmitter and antenna but not much farther. I use Wireless Workbench for coordination. I found the WW default settings for Lectrosonics gear to be a bit too conservative and so I messed around with Wireless Designer to see what intermod spacings it uses, then I set up custom device profiles from that info. And, it helps that of the 49 channels there were 38 UHF and 11 VHF. Personally I think the diversity has more to do with the VHF noiseups than anything. And the fact that these are 30 year old units, some of which have never been sent back for a tuneup ever. I doubt the 50mW had as much to do with it since some of our UHF were also 50mW. Although we had 100mW stuff for that show it was our older 600mHz stuff, and with the 600MHz transition I have moved to 50mW or less across the board. This is mainly because I don't believe we meet all the FCC requirements for part 74 licensing and I prefer us to be compliant. As far as the LMb battery doors, I think it was confined to a small number of transmitters, possibly even only one. I was able to adjust catch for the door a bit tighter. We'll see how things go after that.
  4. Thanks Larry! I'll have to put a wideband multicoupler on my list of possible improvements, since one of our buildings has 5 inline Venues at this point. Thankfully we haven't seen any reception issues so far. In fact our last show was our biggest ever and we had an even longer antenna chain without troubles: SNA600 -> VRWBL -> VRWBL -> VRWBM -> VRWBM -> UMC16 25/26->(VRWBM, UMC200D, UMC200D). The show had 49 transmitters (all Lectrosonics) and the only transmitter issues were a few noiseups on the ancient VHFs and a couple of LMb battery doors coming open.
  5. This topic has raised a couple of questions in my mind: * There seems to be conflicting specs on the bandwidth of the SNA600. I have seen the 30MHz figure, but I have also seen the figure of VSWR <= 2:1 over a 100MHz range, and the comment that the SNA600 fully extended will operate satisfactorily from 440MHz to 600MHz. Does it come down to how we define bandwidth in a particular case? For instance I wonder if the 30MHz spec is -3dB where the 2:1 VSWR might correspond more with -6dB? (and VSWR is a spec more suited to transmitting anyway, correct?) * My personal experience includes feeding block 26 receivers with a pair of SNA600's fully extended with no problems, so I'm doubtful they would offer much protection from new 600MHz cellular interference. In this particular case it was also at the end of a long chain - (2) VRWB Lo, (2-3) VRWB Mid, a two-block UMC16 and a two-block UMC200d with the block 26 receiver in it. * And, would there be any benefit in converting a "chain" of VRWB into a "star" configuration where each VRWB is fed from a wideband UMC16a? It seems there might be slightly S/N for the downstream receivers but I'm not sure whether it would matter real world.
  6. Yes, the firmware at the link is low level, but these transmitters don't have an OS in the traditional sense of the word, just the firmware. The firmware can be updated in the field. Instructions are in the user manual.
  7. Here's my view from last night - front of house at Bob Jones University's first performance of Titanic: The Musical: This is by far the most involved show I have ever run: 49 channels of wireless with a cast of 65+ and 13 wired mics on a 25 piece live orchestra in the pit. The trailer below was shot by our internal media folks at a dress rehearsal. The audio is essentially my front of house mix, so please excuse the large number of open mics at times. We hired 6 professional singers for lead roles, but everyone else - cast, orchestra, crew, and designers - are students, faculty, and staff. EDIT: The embedded video worked for me but doesn't seem to be working for some. Here is a link that may work better: https://www.facebook.com/bjuedu/videos/411084119653155/
  8. So this one was certified in July, before the flurry of ETSI modifications. I should have looked further back.
  9. Geometry seems reasonable for 5-pin lemo... No FCC certifications since November so not likely a new transmitter.
  10. It looks like this has now been accomplished, since firmware v6.0 is now on the web site. From the release notes: VRWB v6.0 - 11 December 2018 Substituted NU Hybrid (NUH) and NU Hybrid with talkback (NTB) for 100 Series and Mode 6 compatibility modes, respectively. Removed REFUMAUS mode. Fixed rounding error in "mhz" serial update command. Thanks to all the folks at Lectrosonics for maintaining compatibility between this now-discontinued product and the current crop of transmitters.
  11. What power would this have been? The original SMV already would have had 50mW - was there an even lower power option available?
  12. I see from snooping the FCC ID database that the re-certifications of all of all current Lectrosonics transmitters have come through in the past few weeks. I have made up a rule that I think works for telling the older units from the newer by the FCC ID on the label: The newer units have an FCC ID that contains an "A" AFTER the band designation. Some examples follow. A simple example is the LMb: FCCID "LMBA1" is LMb in A1 band with 75kHz deviation FCCID "LMBA1A" is LMb in A1 band with ETSI mask compliance and 50kHz deviation. A few are weirder, like the SMWB series where the single- and double-battery models are electrically identical and share the same FCCID. The older models use the single battery model number as the FCCID, but the newer use the double battery model number. However the "A after the band designation" rule still works: FCCID "SMWBA1" is SMWB (and SMDWB) in A1 with 75kHz deviation. FCCID "SMDWBA1A" is SMDWB (and SMWB) in A1 with ETSI mask compliance and 50kHz deviation. For block-wide units, the naming system isn't the same as before either. The older block-wide units shared a common FCCID for several blocks. A band designator of E, L, M, or H corresponded to bands A1, B1, C1, and D1 respectively. Now each block gets its own FCC ID: FCCID "DBZWML" is a WM in block 21, 22, or 23 with 75kHz deviation. FCCID "DBZWM21A" is a WM in block 21 with ETSI mask compliance and 50kHz deviation. Bear in mind that this is unofficial information based on my observations - but I believe it to be accurate.
  13. For a COS11 on an original UM400 you want "universal" figure 5 with the resistor. In fact the universal wiring should work for ANY Lectrosonics transmitter with a TA5F connector. If you know you will only be using UM400a or newer, then you may choose to use the "servo bias" figure 11 without the resistor instead. But figure 11 is not for the original UM400.
  14. We had some SMa (which, I believe, is electrically identical to SMDa except for the dual batteries) for a while and it was my experience that the batteries did run down after being in the transmitter a while. But never so much as to make a noticeable difference just overnight. Any chance you always use the same set of batteries and one is bad? Depending on the way the dual battery setup is implemented internally it could be possible for a bad battery to slowly drain the other - but not fast enough to notice under normal use. As a point of reference, our SMa transmitters would go about 1.5 hours on an alkaline and about 4.25 hours on a lithium. With dual batteries you should be getting in the neighborhood of double that if both batteries are contributing.
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