Interview with Steve Caldwell: RF Engineer at Norwest Group
Ahead of the upcoming summer Olympic Games in Rio, we caught up with Norwest Technical Manager and RF engineer, Steve Caldwell.
Ahead of the upcoming summer Olympic Games in Rio, we caught up with Norwest Technical Manager and RF engineer, Steve Caldwell. Based in Sydney Australia, Steve played a fundamental role in the successful coordination of an ambitious wireless setup at London 2012. As the spectrum landscape continues to change, Steve talks to us about how Rio is conjuring up its own set of unique challenges, while also taking stock of what life is really like for modern RF engineers.Introduction
My overall role at Norwest is to provide support and engineering for all aspects of the business, but my main focus is on Radio Frequency (RF) support for two-way radios, Radio Mics, and In-Ear monitoring. The majority of my time is spent dealing with spectrum, and providing frequency solutions for both Australian and worldwide projects.
I started in this industry around 1998 as a service Technician for Jands, who were the Australian Distributor for Shure. I spent ten years in-house repairing and supporting Shure product, before moving out into the field to gain some experience in RF Engineering.
How did you get into the world of production audio?
I was working for a large domestic electronics retailer, designing and building Home Theatre demonstration rooms. A fellow employee asked me to provide a reference for a job he was interviewing for here in Sydney and he mentioned they were also looking to fill a repair technician vacancy. I gave them a call, and before the conversation ended, I was offered the job.
What's the most challenging aspect of your job?
The most challenging aspect is the unpredictability of spectrum in the different countries we travel to. Out of all the jobs you could do at an event, the RF Engineering and Spectrum Management is never, ever the same. You need to basically start from scratch each and every time. Learning the local Spectrum Authority rules also takes a lot of time and effort. You are a guest in their country, and so must play by their rules.
What's the best thing about what you do?
One great thing is meeting and interacting with the local spectrum Authorities, seeing how they do things, and how they work in that environment. Besides that, I think the best thing is seeing the entire world's attention hanging on all those live radio mics during an internationally broadcasted event, and putting your faith in all your RF engineering and spectrum planning. You're also constantly learning on the job; the more you know about RF, the more you realise how much more there is to learn.
As you've said, your main experience is around RF – often working on globally televised events (the first being the Sydney Olympics) – talk to us about that...
While working for the local Shure distributor, I was asked to sort out some RFI issues with a 20mA current loop (remember those!?) data system running through the catwalks in the stadium that Norwest Productions were using for the Sydney 2000 Olympics Opening Ceremony. Whilst there, I also sorted an issue they were having obtaining the required range from the UHF series radio mics. After sorting both those RF issues, I was asked to stay for the event, and from that first night, I was hooked! From then onward, I was looking after RF for all Norwest's international and local events. I eventually got to the point where using the product seemed more rewarding than fixing it, so I took up an offer at Norwest Productions in 2008 — I've been here ever since and never looked back.
Since then you've gone on to do more of those large events, including, of course, the Olympics in London; can you tells us a little about that experience?
The London experience was amazing. Mainly, I have to say, because of the people I was working with. Ofcom, the UK spectrum regulator, were there in force, but for all their experience and skill in the world of spectrum management, they were extremely humble when asking for help trying to resolve the quantities of performance radio microphones required for this environment. Work on spectrum management for London 2012 ceremonies alone started two years before the event. Over 400 Radio mic, IEM, comms, and two-way frequencies were used for the Opening Ceremony, and all simultaneously. The spreadsheet was huge to say the least. The other folks that deserve a mention are you guys at Shure UK. Tuomo and the team were there day-after-day assisting us with the gear; we were using the recently released Axient systems.
I've been working on the spectrum coordination for Rio since February last year, and the quantity of RF is very quickly outnumbering London. If you count all the Broadcasters, ENG crews, and other users who have applied for frequencies, we are up 860 frequencies and slowly counting, just for the Ceremonies period. A lot of these are 'land grabs' by users, but they have to be accounted for all the same.
How does it feel knowing that millions (if not billions) of people are watching those events?
I actually try not to think about it, and instead concentrate on the systems. Running RF gigs will always come with a degree of risk; I think if I thought about the consequence of poor planning or RF issues too much, I would go mad. It's nice to know that everyone out there — including the international broadcasters — are trusting me to get the job done. All critical frequencies are monitored continuously during the event, and most of the radio mic bandwidth is recorded in the RF domain for scrutiny later on (should it be required).
Can you talk in a bit more detail about the kind of wireless setups you use?
We use a lot of Shure kit. There are many design features in Shure systems designed specifically for big events like Olympic ceremonies, but that's a topic for another day. As for the specifics of systems, the actual transmitters and receivers are off-the-shelf, stock Shure product. All the antenna distribution systems, both for radio mics and IEM, however, are custom designed and purpose built by myself. These systems all involve a huge amount of redundancy that is required for these events, and I've evolved them slowly over the 16 years I've been on the job. With thousands of channels of wireless used across almost 30 major events, we have not yet had a single failure.
How do you keep your wireless setup running reliably?
Carefully. I am fanatical about the treatment of my coax cable and fibre, and their connectors. LMR600 is not cheap coax, and certainly not easy to handle. All feedlines and antennas are FDR and Return Loss tested after they are installed into the stadium, and once again before the event actually starts. All connectors are cleaned and sealed during installation, and quite a bit of effort goes into the protection of the feedlines themselves.
I have been using a custom RF over Fibre system that I cobbled together myself back in 2010, and this requires a little more care than normal. I used it in London where it allowed us to place antennas on the stadium roof; I'm pleased to say we didn't have a single issue over the course of four months — despite the subjection to your English weather!
How is the current on-going spectrum re-allocation effecting you and your operation?
It's mainly affecting us from a product replacement point of view. I have to say that in Australia, the 700 MHz sell-off has not really affected us too much regarding finding usable bandwidth; the real issue is replacing all the equipment we can no longer use. I have managed to licence a 10 MHz chunk of spectrum in the TELCO Mid band gap here in Australia for the last couple of years, so we have been able to retain a small quantity of 700MHz gear for use in this chunk. When doing these large events internationally, we have nearly always been given special dispensation to continue using banned frequencies, so it's difficult to judge the situation in other countries. Most spectrum regulators are quite forgiving with their spectrum, but it could just be the implications of a failed event that encourage their generosity.
What's the most challenging RF environment you've had to operate in, and why?
That would be either Singapore, due to the proximity of the country to its neighbours — and the density of other systems that use those bands — or the upcoming Olympics in Rio. Rio is proving particularly challenging, as they are right in the middle of their Analogue-to-Digital TV transition, and there are only a handful of free TV channels available to fit all two-way, radio mics, and IEM into. It's always things beyond your control — such as TV stations — where you need to be careful. For instance, if you were to do a scan today over in Rio, you would not actually see the 5 or 6 TV stations due to begin transmission within the next 6 months. So as the spectrum planning is already under way, and has been for 12 months, we have to work with a certain set of unknowns.
What was your first experience with Shure?
My very first experience with Shure was back in the early 80's with your HiFi phono cartridges. Back then, I didn't even know Shure made microphones, let alone wireless gear. I still have my V15. The first professional experience I can remember was taking the lid off a U4D and repairing it. At that time, I had a reasonable background in RF from HAM radio and building Coast Guard radio towers, so I had the basics. I spent two years repairing Shure products before I even touched one at an event, which was probably Sydney 2000.
About Steve Caldwell
Steve is a Technical Manager and RF engineer at Norwest Group. He cut his professional RF teeth at the Sydney Olympic Ceremonies in 2000, and has since gone on to serve a plethora of major events across the globe, including (but not limited to) the following:
- Assistant to Audio Project Manager/Service Technician – 2004 Athens Olympic Ceremonies
- RF Engineer – 2006 Melbourne Commonwealth Games Ceremonies
- RF Engineer/Spectrum Mgr. – 2010 Vancouver Winter Olympic and Paralympic Ceremonies
- RF Engineer/Spectrum Mgr. – 2010 Delhi Commonwealth Games Ceremonies
- RF Engineer/Spectrum Mgr. – 2011 Singapore World Youth Olympics
- RF Engineer/Spectrum Mgr. – 2011 Doha Pan Arab Games Ceremonies
- RF Engineer/Spectrum Mgr. – 2011 Auckland Rugby World Cup
- RF Engineer/Spectrum Mgr. – 2012 London Olympic and Paralympic Games Ceremonies
- RF Engineer/Spectrum Mgr. – 2014 Glasgow Commonwealth Games Ceremonies
- RF consultant - 2014 Veracruz Central American and Caribbean Games Ceremonies
- RF Consultant/Spectrum coordination – 2015 Baku European Games Ceremonies
- RF Engineer, Spectrum Mgr. – 2015 Port Moresby Pacific Games Ceremonies
Steve is currently working on what could arguably prove to be his most challenging project to date, as an RF Consultant and Spectrum Coordinator at this year's Olympic and Paralympic Ceremonies in Rio. You can find out more about Steve and Norwest at norwestproductions.com and nwgroup.com.au
