The lobbying group for 50 Ohm Coax has done a great job at destroying the reputation of 75 Ohm Coax. We all now think that if we plug 75 Ohm BNC between our audio carts and our Sharkfins that we might as while kiss all RF signal away. And manufactures know we now fear 75 Ohm so they double or triple the cost of 50 Ohm cable. But is 75 Ohm impedance really the villain? RF Guru and LA based professional sound mixer Jacob Varley doesn’t think so. Jacob Varley is also the tinkering guru who was the first person to add a SMA antenna port to the Lextrosonics LMA. Check out a video he made showing off his cart and antenna distro, most of which is run on HIGH quality 75 Ohm cable.
Now if you want to break it down even further into which 75 Ohm splitters and cabling is good here is another video. This one comes from Ham Radio Op KD7QCU… or sound engineer Drew Brashler if you wanna call him by his human name.
So maybe 75 Ohm isn’t the hero in the RF world… but it’s also not fair to lump it all together. I was in a rough pinch on a travel gig in Buffalo NY and needed to craft a whip antenna on set… I took some scissors and stripped away the shielding on a 6″ long video BNC jumper to make a whip. Worked great and got me through the rest of my gig. Wasn’t ideal; wasn’t pretty; but also wasn’t the kiss of death to my signal we all fear.
Here is a purchase list of the gear mentioned in the above video.
8-Port RF Splitter – http://amzn.to/2AajHis
Log Periodic Antenna – http://www.wa5vjb.com/products1.html
WA5VJB Log Periodic Antenna Tripod Mount – https://www.thingiverse.com/thing:546821
F to BNC adapters – http://amzn.to/2zKHbf7
What’s your experiences with 75 Ohm Coax on set? Share in the comments below.
Andrew Jones is a location sound mixer based in Los Angeles. He started in the TV and Film industry in 2004. You can email him at Andrew@HoldForSound.com