From DC to light on a budget.

Fiber was once an esoteric outlier for audio systems. Not that long ago fiber was largely relegated to telco and networking operations. It’s come a long way since the Bek Technologies snake we put in the Alamo Dome in the early 90s ( I don’t know that they’re around anymore). Now it’s more ubiquitous than a Quicklatch or Mass connector from yesteryear and a twisted pair multicore. In the portable world much of the digital audio and control streams are over unshielded twisted pair cable for shorter runs, fiber for longer runs like snakes. UTP is speced at 100 meters for ethernet so that makes it problematic for longer runs like a snake or in an install (though I recently measured a 387 ft UTP working Dante branch). Combine that with the need more data at faster rates fiber becomes the norm not the outlier.

We’ve seen that over the last couple of decades tactical fiber optic links being used in concerts, corporates and broadcast. What started as a TFOL connector has largely migrated (or is migrating) to an OpticalCON. TFOL aren’t easily terminated in the field even with the expertise and tools. OTOH OpticalCON is relatively easy as it’s based on a common fiber connector (LC) for the insert but the field kits are expensive. For touring types swap it out with a spare and send it to the shop.

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Installs are a different animal. With networks converging between different departments or the need to utilize existing corporate campus networks fiber has become the defacto choice for anything that runs out of the equipment room. Though the show is nearly a couple of decades old I’ve got 110 strands here for audio. The network was initially installed for IP control only with enough capacity that we’d never need to have any more. Or so the designers thought until digital audio and video came along. But it’s OM1 cable and originally a 100 Mb backbone. Hence being a 10/100 net for the first several years of the run. In fact some of the console surface control device ports are still locked to 10 Mb. We’ve upgraded to a 1Gb backbone with 1Gb switches primarily for video and comm though there is a bit of Dante. Without a more current spec cable we can’t get too much more out if it. On a new show in a remodeled room down the street we pulled 108 strands of OM3 for audio with no new copper for a 10 Gb backbone. All the new shows and theaters/showrooms are primarily fiber based. Convention and event spaces have gone to fiber as well.

With that comes the need to be able to work on the links in-house without calling in a subcontractor. There are also some legacy shows that still field strong numbers a couple of decades past the opening that need updated infrastructure. The oldest of those shows had no networking UTP let alone fiber installed during the original build. There was nothing to network. Most people still had dial-up internet access then. Some 9 pin serial cabling or MIDI was as good as it got. Audio trunks were MADI depending on what you were interfacing.

Depending on the tech those shows get upgrades every 5-10 years. The first bits to be updated are usually IP cameras when the SD cameras for show control monitoring were upgraded to HD. A show can have between 20 and 50 cameras modulated and distributed to various departments and operators. Some of the newer shows distribute using point to point switching instead of modulating the feeds. The next bits were upgraded intercoms with digital matrix and IP based PL com. Some of the analog PL lines were too long and required remote power supplies fed by four wire comm ports. Fiber solves this problem anywhere in the room. Or anywhere in the resort property if needed.

The big shows have the capability to pull any cable they need and terminate it. Automation has been doing this for a while as has lighting and projection/LED. In the audio departments the newer shows were built with the needed fiber capacity and the older shows didn’t yet need to be upgraded. Until now. They’ve pulled 50 strands for audio at a show down the street to back haul comm, program feeds, IP cameras and playback. It’s a welcome upgrade. A couple of shows are on upgrade paths for the audio show control systems to be replaced. It’s functionally a console but with far more capability. It’s a full 72” rack or two of gear depending on the size and configuration. They’ll require 10 Gb backbones with distributed I/O through the building. For us that means new strands throughout the building. And they’ll need to be terminated.

That’s where these latest tools come into play. For a while there was a “fear the fiber” mantra with some of the techs. Never mind they could build Lemo or Microdot connectors as well as any multi pin made. But for some terminating fiber seemed almost mystical. Once you see it done or worked around it enough the uncertainty of the unknown disappears like anything else. Not to be caviler as it requires skill, special tools, a devotion to cleanliness and above all patience but it’s not as big a deal as some make it out to be.

The tools are more affordable and more accessible than ever. The variety ranges from barebones to high performance. The choices were made a couple of rungs above me on the ladder. I heard of it when they were ordered and was told “we bought these, how do we use them”. Or more to the point “we bought these for you to use”. The choices were good, lower end tools. Like anything else there are trade offs. It wasn’t that long ago the tools were expensive and there wasn’t much information on how to use them outside formal training. Now we have You Tube where anyone can say they’re an expert in the context of a 10 min video. And also some good online training from outfits like Corning and Fluke as well as a host of other vendors.

For a few grand you can get the tools needed to become the master of your own fiber domain. Of course you’ll practice, right? Right? If not you’ll get what you deserve. To start you’ll need an instrument to measure and “see” the behavior of your fiber over the run. It’s an OTDR. It’s also required to troubleshoot connection issues. You’ll need a fusion splicer. It fuses the ends of the splice together. You’ll need some cleaning and prep tools. You’ll need some specific hand tools for termination. Lastly, as an option you’d be wise to get a low cost power meter.

What we are doing here is splicing connector pigtails or splice on connectors to prepared strands. It’s different from terminating ends by assembling raw connectors, fusing them with epoxy, baking the epoxy and polishing the ends. The bulk parts are less expensive but the skill set is deeper and it takes more time unless the tech is a total badass as in someone that does it everyday. That’s how some developed an apprehension of terminating fiber. Splicing ends isn’t all unicorns and rainbows. There can be cable management issues, access issues that preclude getting the splicer to the location and others. All in all for what we’re doing splicing makes the most sense even though the connectors are quite a bit more expensive. We aren’t doing specialized connectors. We’re using basic SC and LC type ends.

The OTDR I’ve used quite a bit to document and measure the runs. We bought a Speedwolf OTDR-32F. It’s got a basic adapter set and soft case. No launch cable is included so you’ll need to purchase one. We’re using a Fluke launch cable. It’s about $1600 for the both of them. A new higher end unit is in the $6-20k range with refurbs or used starting at a few grand. Like any other inexpensive tool it has drawbacks. The documentation is lacking. The included software is basic with no meaningful documentation though is usable for analyzing the data. If you’ve got some experience working with fiber or read up on the basics of an OTDR you’ll be fine.

The build quality is what you’d expect for a low end tool. The buttons are loose and not positive feeling. They may require another press. The touchscreen isn’t responsive at times. There is an included stylus that helps. The granularity and repeatability of some of the measurements can be suspect. With a 5ns pulse and 150 meter launch cable there was still a large dark zone on relatively short runs. I had issues loading stored files. A reboot seemed to fix it. It stores data in standard SOR files though I haven’t checked to see if anything but the included software will open the files. It’ll be interesting to see how well it holds up. For in house use it will work for us. Our lengths are 100-600 feet. It’s not something that I’d take to a job site were I doing contract fiber troubleshooting. There are a few other brands in the price range that seem to be in similar packages and nearly identical interfaces/software. If you’re on a budget and need to get a tool for contract work look for used or refurb name brands.

While I have experience with fiber and network testing tools I’d never terminated fiber myself. I’ve seen others do it but until now haven’t had the opportunity or need. We purchased a QIIRUN AI-6C fusion splicer for about $800. The kit comes with a hard case (knock-off Pelican type) and an assortment of termination hand tools. The included tools are marginally acceptable. There are a couple of strippers and a cleave tool. The cleave tool is the best of the bunch but still not exactly precise. It’s about a $75 tool on its own. I was able to use them but we opted to pick up a Jonard fiber kit and cleave tool at about $1600 for the both. It’s all about the prep. It’s like buying a specialized crimper. Best to get the one with the proper mandrels for more money than futz with making something substandard work.

While I’m a noob at using a fusion splicer I’m happy with the tool. It took an hour so so before I felt comfortable and could get consistent with the included tool set. I still would like a bit more practice with the improved hand tools before hitting the field. As with any low cost import tool the docs are sparse but in this case more informative than the OTDR docs. There are also several videos on You Tube from various sources on how to use the splicer. This is another tool that is marketed under different brands though the identical tool.

The build quality is acceptable even at this price point. The buttons are tactile and the moving parts have no decerable slop. The display is clear and responsive. The cameras focus well and the motors move freely to auto align the fiber. One part I wish were improved are in the cable holding mechanism. The grooves could be a bit more precise with more groove options for various diameters. The case doesn’t appear to be a high impact plastic though I’m not ready to drop it to be sure. All in all it’s not difficult to use.

Like the OTDR I’m wondering how long the tool will last or how long it will stay in calibration. The battery could be a concern long term though we have the ability to replace the cells in most any rechargeable battery. As long as we can get those specific cells. If you’re going to be doing this for a living it’s better to get something where you’ll be able to get replacement parts. Unlike the OTDR the splicer uses electrodes that wear out after a while. A brand name like Sumitomo or Fujikura will allow you to get parts and service for years. I’m not so sure on this one though they have a US support number.

We’re into it for about $3500. Or about what it would cost in outside labor to upgrade the show we already pulled. With fiber now being the primary distribution it makes sense for us to bring it in-house considering the number of shows that will need fiber pulled for upgrades. The price difference between what we bought and the brand names is substantial. Along the lines of buying the least expensive Harbor Freight tool or shopping on the Snap On truck. The pair new depending on brand and model is around $12k to start. Given the requirements and expected duty cycle of the tool I think for many in-house uses it’s a good choice in spite of the drawbacks. Time will tell though. If it doesn’t last more than a few hundred ends it won’t be worth it in the long run. We’ll see.

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