Issue link: http://digital.copcomm.com/i/757053
64 F A L L 2 0 1 6 C A S Q U A R T E R L Y back to a wireless utopia. #nerdalert … With a 100-foot run of Belden 8240 (RG-8A/U) cable, you will experience almost 12 dB of loss. You could run 100 feet of Belden 9913F7 (that thick RG-8 cable) and you would possibly not need much amplification if any at all. Maybe +4 dB if you wanted. But with Belden 8240, this cable is thin enough for temporary remote runs that are practical for production sound (non-installation) use. Just add 12 dB of gain at either your active antenna's amplifier or an in-line amplifier. This could feel like a return to the old days when you'd want to get that VHF antenna for your Vega wireless right on the frame line! That was a dark time for wireless in production sound and I don't see its permanent return. I don't feel like we need to finesse our habits that far. This becomes one more thing to throw at our boom operator and utility personnel who already have their hands full as a result of the large num- ber of wireless microphones in production. But with a little closer proximity antenna placement, high transmitter power becomes less of a needed element. Reducing your transmit- ter's power output has several advantages, including avoiding intermodulation and transmitter heat generation. If this finessed placement becomes standard practice, I think our performance expectations can return to what we deserve— despite the unfortunate coming RF crunch. THE 50 MILLIWATT QUESTION Unlike live theatre applications, where 50 mW transmission is the norm, TV and film production sound applications have had a tool at our disposal for increasing transmitter power to the maximum of quarter-watt. Sometimes this helps us "squeak out" just enough range from a transmitter to pull off a scene where either long distance or an unclean frequency are the challenging factors of reception. But, what if the maximum we are allowed to utilize is a 50 mW trans- mission on body pack and boom transmitters? How will this affect our antenna placement choices? I don't know if this would ever be a legislated limitation, but I think we should safely assume that it could be. As a user of some transmitters that are limited to 50 mW, I can attest to the fact that the way to make these work to our expectations is with a fairly close range and clear air. If those two things are not guar- anteed, antenna placement must compensate for the lack of close range. This is where these remote antenna techniques may come in handy. PRODUCT OPTIONS Here are some of the antennas that I'm familiar with that are widely available for purchase for production sound mixers: Lectrosonics ALP620 Log Periodic Dipole Arrays, Zaxcom Bluefin Log Periodic Dipole Arrays with a cardioid directivi- ty, RF Venue Diversity Fin with a cardioid LPDA and omni- directional dipole in the same unit, Lectrosonics SNA 600a dipoles, Wisycom ADN-ADB, Shure UA860SWB omnidi- rectional antennas. Also, Sennheiser A5000CP, Professional Wireless HA8089, and the RF Venue CP Beam (which are all helical antennas). Powered options that I know of include: The Lectrosonics ALP 650, Wisycom LNNA, Besto Sharkies, and PSC Powerpaddles. All have active antennas with amplifiers located on the antennas themselves. These come in very handy when you have that 100-foot run and need to compensate for the loss incurred from the cable length. Even more handy is the Besto, Wisycom, and PSC units which have variable amplification—adjustable on the antenna amplifier itself. This allows a variety of antenna cables and lengths as well as attenuation when needed. All of these are great tools but what are we missing? WISH LIST I would love an extremely robust system that would allow the patching of multiple RF signals of both receiving antennas and transmitting antennas into a digital, battery-powered balun that would utilize fiber optics to allow these signals to travel down one extremely lengthy (500-1000 foot?) line. I also feel we are lacking good options for new VHF antennas, where a certain amount of metal needs to be used to con- struct these in order to work and have increased gain. But I Wisycom ADN ADB Wisycom LNNA Zaxcom Bluefin