Q&A with Henry Cohen, RF Coordinator to the Presidential Debates

This past Monday the first Presidential Debate was held. Every member of the press going into this debate was already calling it boring; And when the press gets bored at mega events they often look around and start to complain about their working conditions. (see Sochi 2014, Brazil 2016, the DNC/RNC 2016 Conventions)

This past Monday that was not the case.

Tuesday morning I opened up my Facebook and found a post in a sound mixing group praising the frequency coordinator, Mr. Henry Cohen. For those that aren’t familiar with what a frequency coordinator is; they are like the air traffic tower at an airport.
The position is independent from all media outlets, but dictates whom can be on what frequency for their wireless microphones (really any wireless device.) This way the BBC isn’t stepping on an NBC reporter’s handheld wireless’ signal and for 90 minutes, all
press agencies get along.

I got a hold of Mr. Cohen’s phone number from the Presidential Debate event host, whom was handing it out to media outlets. At first I wrote it off as having to be tied to a burner phone that they gave him for the event or
maybe even a land line that went to a pipe and drape work space at the venue from where he was manning during the debate. I took a chance, sent a text to the number and asked for an email Q&A interview. Sent! A minute ticks by and the automatic
message from Verizon saying the number goes to a landline doesn’t arrive. Another minute passes and the response pops up on my screen. An email address and the sentence “Sure, send it over” appears.

So without further delay here is my Q&A with Henry Cohen.

1) How did you get started doing frequency coordination?

I had been working with RF mics on musical and theatrical tours in the 80’s and early 90’s. That was my first exposure to the coordination process. I got
more heavily involved as wireless production equipment became more prevalent in the mid 90’s and was asked to help mitigate RF problems.

2) When you get the call for an event like the presidential debates how do you prep for them?

If I’m called early enough, I try to get the client to integrate the RF coordination notice and request form into the credentialing process form the beginning.
If I’m called too late for that, then the notice and forms get distributed via alternative means. Either way I then try to educate the media folk on the process.

I’ll contact the local SBE coordinator to see what already exists in that particular market and try to work with their established broadcaster assignments.

Get a clear understanding of the venue/sites overall and the RF operational areas in particular.

Establish the RF needs of the production itself.

Perform an RF site survey as far in advance of load in as possible. Not always agreed to by client, and if so, I’ll rely on secondary sources of spectrum

Pre-coordinate the show elements and the visiting bands and/or ENG as much as possible before arriving on site (which generally involves a significant number
of emails with folks having RF requirements.

Get frequencies to those who requested coordination before they depart their facilities.


3) Did you have to shift your plan for coordinating frequencies midway through the event? And if so how did it shift?

No shift plans. Only start to tighten up who can be coordinated as spectrum gets more congested based on the caliber of their equipment and band split(s).

4) Any tips for sound mixers who have to balance out 8 wireless kits in their audio bags?

IFB’s and IEM’s on one side, and mics on the other. Try to use a multicoupler on the RX and get small remote antennas as far away from the TX as possible.
Conversely, try combining all the transmitters into one or two antennas and place as far from receivers and RX antennas as possible. Make certain your frequencies are in fact a coordinated set, and incorporate some band planning (e.g. a block for just IFBs
and camera hop TX, and different block(s) for mics).


5) What block was most requested this year at the Presidential debate?

In general the entire UHF TV band (low 500’s to 698MHz) becomes congested fairly evenly.

And how can a sound mixer working for a media outlet ensure they will be able to use a wireless mic at a large event like this?

Once they get the assignment, the first question should be what information did the media outlet get regarding frequency coordination. If that question does
not produce meaningful information, ask for the event’s media or credential contact information and then contact them directly asap for the frequency coordinator’s information. Be prepared to bring, rent or buy additional frequency ranges if current inventory
is already blocked out by the time coordination is requested.


6) Without naming the media outlet what was the craziest violation of RF at the debate?

None. Virtually everyone there was (is) an experienced professional, and those new to the process were cooperative.

7) In the past few years more manufactures are producing 2.4Ghz items; Have you seen seen an increase in their usage at events and how do you go about coordinating devices that usually don’t offer a lot of controls over frequencies?

I have not seen 2.4GHz mics in professional environments. It would be foolish to try to use a mic in that spectrum given the tremendous WiFi presence and
expansive installed WLAN infrastructure.

8) In your opinion is the 2.4Ghz spectrum a reasonable solution for wireless microphones?

In what application? Not in a professional work environment. Maybe for a bar band or karoke.


Is it as crowded as the 500mhz space or is that all a myth?

At these types of events 2.4GHz makes 500MHz look barren.

9) For those wanting to move from being a sound mixer to being a sound super, coordinating a dozen channels of wireless is key. What resource would help mixers that want to make this move?

First would be a basic academic understanding of the physics and principles of radio frequency propagation, antennas, spectrum usage, transmission schemes
(generic analog vs digital), spectrum allocations and utilization. For this, I highly recommend any and all of the excellent RF guides on the Lectrosonics, Sennheiser and Shure web sites, along with the ARRL’s
ARRL Handbook (http://www.arrl.org/shop/ARRL-Handbook-2017-Hardcover-Edition/), and the
ARRL Antenna Book (http://www.arrl.org/shop/ARRL-Antenna-Book-23rd-Hardcover-Edition/).

Knowing how to use the FCC’s TV Query database search function, or use one of the major manufacturers’ online spectrum/market search engines.

Having a proper IM prediction software program – and truly knowing how to use and understand the software – for those times when operating apart from others.
Sennheiser’s Wireless System Manager (WSM) and Shure’s Wireless Workbench (WWB) are very good free programs, while Professional Wireless’ Intermodulation Analysis Software (IAS) is the professional tool of choice.

Have good equipment resources. Different frequency bands (blocks) will be better for certain markets and worse in others.

I hope you enjoyed this interview. Comment below and share it on social media.

profile-picAbout the Author

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


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