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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Wireless and Communications => Topic started by: Neil White on September 12, 2015, 06:54:18 AM

Title: RF system preparation
Post by: Neil White on September 12, 2015, 06:54:18 AM
So I think much of the success or failure of the deployment of RF systems comes down to attention to detail. With that in mind, I thought it would be interesting to discuss some of the things that can make the difference, perhaps both from the perspective of engineers who are using the systems and the rental companies supplying them.

To get things started:

Fresh or fully charged batteries in all transmitters and IEM packs.
All settings matching across all transmitters / receivers. Much easier to check before handing out the packs to the artists that the squelch / limiter / eq / balance is set consistently across all the systems.
Good labelling. I've seen both silver sharpie on black tape or PTOUCH labels (white on clear) work well.

What other details do you look for in a well prepared RF package?
Title: Re: RF system preparation
Post by: Jens Palm Bacher on September 12, 2015, 08:29:29 AM
So I think much of the success or failure of the deployment of RF systems comes down to attention to detail. With that in mind, I thought it would be interesting to discuss some of the things that can make the difference, perhaps both from the perspective of engineers who are using the systems and the rental companies supplying them.

To get things started:

Fresh or fully charged batteries in all transmitters and IEM packs.
All settings matching across all transmitters / receivers. Much easier to check before handing out the packs to the artists that the squelch / limiter / eq / balance is set consistently across all the systems.
Good labelling. I've seen both silver sharpie on black tape or PTOUCH labels (white on clear) work well.

What other details do you look for in a well prepared RF package?
Good, recently tested, rf cables. Bonus point for writing the RF loss on the cable.
A good selection of spare products and spare frequencies.
Clamps and bars to mount antennas.
Foam windshield for HH's and miniature mics. Proper rycote fur if used outdoors for speech.
Title: Re: RF system preparation
Post by: Neil White on September 12, 2015, 05:04:32 PM
Good, recently tested, rf cables. Bonus point for writing the RF loss on the cable.

There has been plenty of discussion about RF cable, but mostly with regard to the connection between rack and antenna. Are people using the manufacturer supplied cables  (often RG58) that come with most equipment for connections within the rack between receivers and antenna distro for example? Or is there an advantage to building short links with something like LMR-195?

Title: Re: RF system preparation
Post by: Pete Erskine on September 12, 2015, 05:21:14 PM
There has been plenty of discussion about RF cable, but mostly with regard to the connection between rack and antenna. Are people using the manufacturer supplied cables  (often RG58) that come with most equipment for connections within the rack between receivers and antenna distro for example? Or is there an advantage to building short links with something like LMR-195?

I stick with everything, even 25' LMR440UF N.  I USE 2' BNC AT ANTENNAS TO PREVENT STRAIN.
Title: Re: RF system preparation
Post by: Lyle Williams on September 12, 2015, 05:34:44 PM
Make sure you have a plan for where the bodypacks will go.  Something that works with the energy level of the act.
Title: Re: RF system preparation
Post by: Henry Cohen on September 12, 2015, 07:51:55 PM
There has been plenty of discussion about RF cable, but mostly with regard to the connection between rack and antenna. Are people using the manufacturer supplied cables  (often RG58) that come with most equipment for connections within the rack between receivers and antenna distro for example? Or is there an advantage to building short links with something like LMR-195?

In high RF noise environments using double shielded coax for short jumpers will reduce stray RF from getting into the coax and decreasing the CNR in the receiver front end.
Title: Re: RF system preparation
Post by: Don Boomer on September 13, 2015, 11:21:03 AM
LMR-195 is pretty cheap insurance. Since you never know which straw is gonna break the camel's back I use it for all my small diameter coax.
Title: Re: RF system preparation
Post by: Jason Glass on September 13, 2015, 01:07:32 PM
LMR-195 is pretty cheap insurance. Since you never know which straw is gonna break the camel's back I use it for all my small diameter coax.
Same here. They make leakage losses and crosstalk a non-issue.
Title: Re: RF system preparation
Post by: Lyle Williams on September 13, 2015, 03:44:23 PM
While LMR-195 is a nice coax for the size/price, I think the benefits can be overstated.

My internal rack jumpers are LMR-195, but if I somehow kinked or broke a cable in the field I'd swap it out for cheaper RG-58 without hesitation. 

If I was truely caught short I'd even swap it out for a cable with the wrong characteristic impedance like RG-59.