Friday, December 29, 2006

Coaxial cable

What is Coaxial Cable? (

Coaxial or Coax cable is so named because the signal inside the cable runs on two (co-) axies: the center conductor and the shield. This is a relatively old cabling technology that was originally developed for military use. Coax cables were found to be so durable and efficient at carrying all sorts of signal types from data, video, audio, and more, that the standard soon became commercialized. Today, coax remains a very popular cable assembly type for cable TV, antennas, high-end audio/video equipment, and security equipment.

Though there are a few standards of coax cable available on the market, L-com only really carries the "RG" styles. RG stands for radio guide, and each cable type is generally called by RG followed by a number indicating the standard number of the cable. That is sometimes followed by a letter to indicate a sub-standard, and then the letter "U" to indicate that the standard is universal. But all this doesn't help you figure out what kind of cable you need!

With coax, the application generally dictates the kind of cable. Video cables nearly always use 75 Ohm styles of cable. Data and antennas usually use 50 Ohm styles. The different styles may have different flexibilities, diameters, attenuation, jacket types, and other factors that make one cable the ideal fit.

If you have an application but don't know what cable you need, try giving us a call or emailing directly to our tech support group at You may also find our Coaxial Cabling Tutorial helpful, available free on our web site.

Wednesday, December 27, 2006

The holidays are drawing to a close, but L-com sales are still on!

Plenum Patch Cables (Fiber Optic and Ethernet UTP) Sell-Off (

As the year ends, we took a look around our massive warehouse and noticed many boxes of custom Plenum rated cable products built for one of our customers who didn't end up needing them. Well, we don't need them either, so we've decided to sell them at incredible prices just to give us more space!

The link to the items on sale is here:

Among the items are a variety of multimode and singlemode fiber optic patch cables, OFNP or Plenum rated, and various colors and lengths of Cat 5e and Cat 6 rated Plenum Ethernet cables. And the prices are so low, some of them are even cheaper than our PVC cables!

Along with that, the Overstock Sale that we started a couple of weeks ago is still going on, so check that out as well.

Hope your New Years is a happy and prosperous one!

Friday, December 22, 2006

L-com closed for Christmas

L-com Connectivity Products

Hope your holiday is bright and merry! We will be closed on Monday, December 25th, in observation of the Christmas holiday. Then there is one week left to the year and to the End Of Year sale that is still going on!

Merry Christmas

PS. If you haven't gotten your 2007 L-com Calendar FREE from us, yet, call your inside sales rep and ask them to send you one!

Wednesday, December 20, 2006

IEEE-1394 cable assemblies (also known as FireWire)

Firewire cables and technology (

Firewire is an interface type that's been growing in popularity. Like USB, it is usually used to connect peripheral devices to computers, but it is also sometimes used to connect peripheral devices together with no computer in between. Because IEEE-1394 isn't asynchronous like USB is, you don't need a processor to manage the signals.

Does that mean that Firewire is "better" than USB? Not really, it's just different. Really, USB is far more popular right now, and maybe for that reason Firewire is often confused with USB.

Here in L-com's tech support department, we sometimes get the question, : "How do I convert USB to Firewire." But unfortunately, we don't know any easy way to do that. The problem is that USB is very different from Firewire, like two different languages. The cost to design a device that would convert one media to another is more expensive than the cost to just buy a Firewire PCI card and put it in your computer. So, if you have Firewire devices that you need to plug into a computer with only USB ports, you should probably consider getting a Firewire card to give you the proper ports.

There's been a lot of talk recently about the new Firewire 800 or IEEE-1394b standard and products for it. Right now, we're carrying an assortment of cable assemblies to meet the standard, and as demand grows we will add more products to support 800Mbps devices.

Friday, December 15, 2006

L-com's End of Year 2006 Sale!


Happy holidays to our blog readers and L-com customers! As a token of appreciation, our sales reps sent out the below email on Wednesday:


Happy Holidays and thank you for being an L-com customer! 2006 was a very successful year for me here at L-com, and I’m hoping it was a good year for you too.

Because I appreciate your business, I want to make sure you know about a special End Of Year Sale going on here. I picked a couple of items I thought might interest you, but if you want to see a complete list of many more items click here.

You can’t access this special sale list from our home page, so I’m sending you the link specifically by email. Copy and paste it into your browser:

If you want to discuss your projects or connectivity needs, please give me a call or send me an email! I look forward to working with you in the year to come. Have a happy and prosperous New Year!


L-com Sales Department

69% Off Regular Price!
60% Off Regular Price!
53% Off Regular Price!

I want to extend the same invitation to our blog readers! If there is anything we can do for you, let us know!

Wednesday, December 13, 2006

What is GPIB (IEEE-488)?

L-com explains IEEE 488, also known as GPIB or HPIB

GPIB stands for General Purpose Interface Bus and is really a connectivity standard, known mostly by its IEEE file number: 488. Originally, this was a great way to connect machines because you could "daisy-chain" multiple GPIB cables together.

Nowadays, GPIB isn't used as much. However, there are still a lot of machines already in use, some of them very expensive or difficult to replace, that use the IEEE-488 interface. For that reason, GPIB cables, connectors, adapters, and other products are still in demand to keep these machines connected.

The IEEE-488 standard uses a "CN24" type connector, sometimes also called a Centronics 24, or a micro-miniature 24 pin connector. It has 24 pins arranged around a rectangular opening.

Most cables with this connector have both male and female interfaces at each end of the cable. This is how you can daisy-chain the cables together: by plugging the male end of the connector into a machine, you leave the female end exposed so you can plug another male cable into it. Usually the female side is in the same orientation as the male, called "normal orientation", but in cases where you want to daisy-chain in a straight line, it is usually best to get "reverse orientation" cables so you don't have to curve the cable up over the connector when you plug it in.

Of course, since there are so many newer bus standards, people are often looking for ways to convert GPIB to USB. L-com carries a GPIB to USB converter that can help you set up a laptop and plug it into machines that use the GPIB interface.

Because GPIB is such a rare interface nowadays, we often get questions about it, so please give us a call or send us an email if you want to learn more!

Monday, December 11, 2006

L-com Media Converters to change from one signal type to another

All about L-com Media Converters (

Sorry I haven't posted much in the past few days. We're closing in on the end of the year and working hard to be ready for our 25th Anniversary Year! But in the mean time, I'm back with a quick post about L-com's media converters.

Obviously, the point behind a media converter is to convert a media type. But what does that mean, exactly? Different types of media (or signal transmitting methods) come with different advantages and disadvantages.

For instance: fiber optic cables are immune to EMI and lightning strikes and can carry a signal a long distance, but they can be expensive and sensitive to shock and impact. Twisted pair cables tend to have a length limit of 100 meters and can't be bent or flexed too tight for fear of untwisting the pairs, but they can transmit at high speeds. Coaxial cables tend to be more robust than most other types of cables but they also tend to work at slower speeds.

Because a single cable run may go through multiple environments, it makes sense to convert the media as the environment requires to get maximum efficiency. Common media converters include fiber optic media converters, coax media converters, and interface converters. L-com also separates the converters we carry by manufacturer. If you don't know which manufacturer you prefer, try using our Ethernet Converter Wizard tool, or shop by converters, whichever is more convenient.

And, of course, if we can help you choose the best item, let us know!

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Monday, December 04, 2006

KVM Switches That Allow Multiple Monitors

AdderView Multiscreen Reverse KVM Switches (

KVM switches are a constant fascinations of our customers, it seems. They are both functional and empowering, allowing a user at a single workstation (consisting of a single monitor, mouse, and keyboard) to control several, independent computers. In some cases, users can control hundreds of computers this way without having them networked together.

But what happens when you want to share computers among several monitors? For instance, you could have different computers processing separate reports and want to monitor them at the same time.

AdderView has just such a switch that L-com resells for them. The Multiscreen KVMs allow up to 4 monitors to connect to two or four computers. Then, with a single keyboard and mouse to control them all, you can cycle through the active computers and look at each on a separate screen. The units allow hotkey switching, but also have the options of RS232 data commands or a remote controller. Need more monitors and computers? You can uplink several of these units using a "Smartview cable".

Of course, it's a little geeky in some situations, but don't you have any geeks on your Christmas list?

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Friday, December 01, 2006

L-com's new factory in SuZhou, China

L-com Opens a New Factory Overseas (

We were excited to read in Connector Specifier that Bel Fuse (who makes the Stewart brand modular connectors that we sell) had opened a massive factory in China. We don't have anything near that size, but we're pretty proud of our own new addition, which we announced just a few days before Connector Specifier ran Bel Fuse's announcement.

Of course, we make different sorts of products than Bel Fuse, too. We expect our factory to make cable assemblies, connectors, adapters, and more, saving you money and, hopefully, time. We're also looking forward to being better able to create innovative new products now that we have more full control over some of our overseas manufacturing.

Yes, we've always had control of our domestic manufacturing. As we mentioned when we talked about our domestic and overseas custom manufacturing capabilities, we have our own factory here in North Andover, Massachusetts. And that isn't changing at all. This is just the first time we've wholly owned a factory outside of the US.

So, though humbled by Bel Fuse's 15 acre plant, we're still very proud of our own facility and our industry-famous flexibility and capabilities. And we're always proud to serve you!

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Wednesday, November 29, 2006

L-com's Coaxial Connector Adapters and Couplers

Coax Adapters and Couplers from L-com Connectivity Products (

I saw the announcement in ECN magazine's website about Bomar Interconnect Products' new coaxial adapter, and I thought this might be a good opportunity to explain what coax adapters are.

L-com carries a wide range of coax adapters and couplers, as part of our main coaxial product line. We separate out within series coax couplers, which have the same type of connector on both sides, from interseries coax couplers, which have a different connector type on either side. We also separate out right angle and coax T adapters and bulkhead style within series adapters.

The bulkhead within series adapters are some of our most popular. The term "bulkhead" refers to the ability to mount these couplers on a panel or faceplate, so they are very useful when setting up installations in a building or making custom rack panels in a wiring closet.

The interseries coaxial adapters are also popular. They allow you to connect two dissimilar cables together. For instance, if you have an antenna with an SMA connector on it, and you're trying to extend it using a cable with TNC connectors, you'd need an SMA to TNC adapter to make the switch.

There are a lot of coax adapters available on our web page, and sometimes it gets tricky to find what you need. In that case, use our Adapter Wizard feature! It walks you through choosing the features on the adapter that you need and even has pictures for easy identification.

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Monday, November 27, 2006

Shielded Category 6 Rated Ethernet Cables

Shielded Modular Cables (STP) with Cat 6 Rating (

For a long time we were getting requests for Category 6 rated cable assemblies that were shielded. The problem: we couldn't find anyone who carried the bulk cable we would need to make the assemblies. That changed last year, and we've been pleased to offer two varieties of shielded cat6 cables in multiple lengths since then.

The first variety, our TRD695SCR series, has a PVC jacket. They are fully shielded (100% foil) with 26 AWG twisted pairs that conform to Category 6 standards, capable of carrying speeds of up to 1000 Mbps (mega-bits per second). These cables are ideal for Gigabit speed transmission.

The second variety, our TRD695SZ series, is the same as above except it has an LSZH jacket. LSZH (Low Smoke Zero Halogen) is specially formulated to have very little smoke if the cable burns, and the smoke does not have toxic halogens that PVC releases. These are ideal in situations where people might not be able to easily get out in the case of a fire, like submarines, airplanes, elevators, and very tall buildings.

The shielding on these cables helps prevent electromagnetic interference (EMI) from riding along the conductors and causing "noise" at the end of the cable run. This is especially important in some environments where there is a lot of noise around, such as near high-frequency electrical equipment, antennas, and power lines. Excessive noise on a line can slow down transmission or completely drop connectivity in some situations.

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Wednesday, November 22, 2006

Happy Thanksgiving!

Happy Thanksgiving! (

To all the Americans that read our blog, we want to wish a very Happy Thanksgiving! L-com Connectivity Products is going to be closed Thursday and Friday this week so we can go "connect" with our families! Then, bright and early on Monday we'll all be back, hard at work to bring you cables, connectors, adapters, and more!

Monday, November 20, 2006

How to Extend USB

Extending USB Signals Beyond 5 Meters (

The "U" in USB might stand for "ubiquitous serial bus", because USB seems to be everywhere. If you don't have at least six USB ports on your computer, its time for an upgrade, because cameras, printers, scanners, webcams, even snowman robots are using USB cables to get power and communicate with computers.

The big frustration with USB, though, is the infamous length limitation. If you want to put a printer or webcam more than 5 meters away from the computer that controls them, you run up against this technological block. Fortunately, the industry has evolved methods of overcoming this problem, so now all you need to ask yourself is "How far do I want USB to go?".

USB Extension Over Short Lengths

If you just need to go a little above 5 meters, up to 25 meters (about 50 feet) or so, then a very economic solution is a simple USB extender cable, like L-com's TL-U026-016. It couldn't be more simple: just plug up to five of these cables together, plug the male connector into the computer, and plug the peripheral device into the female side, and everything connects!

USB Over Category 5e Cable

Another trick is to convert USB to Category 5e copper cable format and use UTP cable to connect the two. These sorts of devices are usually a little more expensive, but can get the USB signal up to 50 to 100 meters away. When you are looking for this kind of a solution, make sure the converter you buy works at the USB speed you need (1.0, 1.1, or 2.0), and also make sure you have power available at both the computer and peripheral device locations.

USB Over Fiber Optic Cable

If you want a lot of distance between computer and peripheral, a final choice is to convert the USB signal to fiber optic light signals. This is the most expensive option, but some converters can let you connect up to 500 meters away from a computer! Like the Category 5e converters, your fiber converter may require power and may not work at USB 2.0 speed. Check before you buy!

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Friday, November 17, 2006

Waterproof, IP67, Indoor/Outdoor Electrical Components

Weatherproof cables, connectors, and couplers that can resist the elements (

Connectivity products aren't just for the office any more! More and more companies are developing products for use outdoors, including transportation products, GPS systems, outdoor computers, and ports on the outside of buildings for connecting laptops or peripheral devices. The problem is that electronics don't mix well with the elements, and outdoor-rated connectors and components are more and more in demand.

L-com carries a significant waterproof and IP67 rated product offering. Most of these are IP67 rated connectors, but there are also some completed cables (including Ethernet cables and USB cables). In addition, there are waterproofing grommets that can fit on a cable (before it is terminated), connector covers, and even an outdoor rated enclosure.

These kind of products are affordable and stocked domestically, so they're relatively easy to obtain and use.

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Wednesday, November 15, 2006

Custom Fiber Optic Cables in as little as 2 Days

L-com can manufacture fiber optic cable assemblies domestic in as little as 2 days (

That's right. Where a lot of other companies outsource their fiber cable assembly production (sometimes to us!), we manufacture our own right here in North Andover, Massachusetts. That means that if you need a cable at a length that we don't stock, we can usually make it pretty quickly for you at no extra charge. Better yet, we don't even require a minimum order quantity for doing it! So long as it uses components we stock here, we can put it together for you.

Cables like MTP ribbon fibers, however, are not done domestically, so the lead time takes a little longer. Usually, in those cases, its about 1 to 2 weeks, and we still try to keep the minimum order quantity as low as possible, usually 1 piece.

The advantage of getting a fiber made to your specific length is that you could save money by planning ahead. If you have a few days to wait, we could build the fiber cable assembly so that you don't have it any longer than you need. That way, you don't pay for extra bulk cable that isn't being used. In addition, you won't have to worry about coiling up and tucking away the slack on a fiber line once it is run.

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Monday, November 13, 2006

L-com CAD models and Engineering Drawings

Free 3D CAD models and 2D Engineering Drawings on L-com's Web Site (

It's only been about 3 months now since L-com started offering free 3D CAD models on But the response has been enormous. Design engineers like that they can download the CAD models to integrate right into their designs. Electrical engineers and installers like that they can turn and rotate the product to see it from other angels before they buy.

L-com offers the free engineering support in 3 ways on its web site. First, you can go to any product that has a CAD model available, the bulkhead DB9 F/F gender changer (DGB9F) for instance. Make sure the "3D" radio button beneath the picture is clicked, which may cause an automatic download for the first time you click it. Then you can rotate, pan, and zoom on the image without needing to log in!

Second, you can download a .step version of the model to integrate into your own designs. To do this, you will need a log in email and password, but registration for that is free and quick. Once registered, click the link at the bottom of the page that says 3D CAD Model and your download will start.

The third free engineering perk that L-com offers on its web site is the 2D engineering drawing that you can download (also with free registration). This has a lot more detail on the product's construction and recommended panel mounting dimensions.

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Friday, November 10, 2006

Panel-mount RJ45 couplers - L-com's ECF504-SC5E

Flange-style bulkhead Ethernet adapter (

One of L-com's Top 10 Adapter products is a popular flange-mount Ethernet coupler that is both shielded and Category 5e rated. It uses screws to hold it in place, and is therefore a little more secure than other panel-mount adapter styles.

It has the same connector on the front as it does on the back: female RJ45 8x8 connector. However, L-com also carries an RJ45 female to 110 Punch Down IDC adapter with the flange as well. Both of these items are tremendously popular, so L-com stocks them in the thousands to keep ahead of demand.

The shielding on the flange makes contact to ground through the screws, so make sure you install this in a metallic chassis or panel if you plan to use shielded Ethernet cables.

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Wednesday, November 08, 2006

Plenum SVGA cables prices dropped

L-com drops the list prices for Plenum rated SVGA cables (

Most of the cabling industry right now is raising prices due to the increase in the price of raw materials like copper, gold, and petroleum. But recently, L-com announced a major decrease in price for one particularly expensive type of cables: Plenum rated SVGA cables.

To give you an idea of the scope of the price change, L-com's CTL3VGAMM-50TP Plenum rated 50 foot SVGA cable retailed at about $680.00. With the new price decrease, that same cable sells at L-com at $335.00, a significant boon to installers and integrators who need Plenum rated cables to install in buildings.

Plenum rating has to do with the flammability of the material used in the jacket of the cable. It doesn't affect how well the cable performs, but some buildings have fire codes that demand only Plenum rated cables be used in certain situations. Because the cables are so expensive normally, installers would have to raise their prices and lower their margins. L-com's change helps them out a lot.

The name "plenum" refers to an airspace, usually a duct-way, between floors in a building. When installers are pulling cables between floors, often the easiest place to pull them through is the plenum. However, normal PVC jackets burn quite easily, and in the event of a fire on one floor, the flames can climb the cables and "jump" from floor to floor. This makes it very difficult to fight the fire and necessitates a special type of jacket that is more flame retardant. L-com posted a really neat video showing the different types of cables burning on its web site.

Monday, November 06, 2006

Custom Cables and Equipment Manufacturing

Customized cabling products manufacturing services (

L-com is in a unique position in terms of manufacturing custom products. We're both small enough to give custom product requests individual attention, and yet big enough to accomplish most jobs despite size and complexity. We also have both a domestic factory and overseas facilities so we can offer solutions for various needs.

What is your MOQ?

MOQ stands for Minimum Order Quantity, and we know it's the bane of most buyers' and design engineers' lives. Fortunately, L-com can work to keep MOQs low in most situations. For instance, fiber optic custom length cables have no minimum order requirements because we make them domestic all day long. Assembled
d-subminiature cables have low MOQs (usually under 50 pieces) because we can set up product lines here in the United States. For more complicated jobs, the MOQs go up, but since we have so many contacts overseas, we can usually keep the MOQs to a reasonable level for those as well.

How to get a custom

The easiest way to request a custom part is to download the custom product form or copy it from the back of our catalog. Then, fill it out and fax it to us at 978-689-9484, or email a scanned in version of it to We also offer a custom product assistant form to help you articulate what you want. Within a day or two, we will respond to your request. If we quote you a good price and you place an order, we'll custom design an engineering drawing draft for you to review and approve before we build anything. Once you've approved that, we'll build it to our ISO 9001:2000 standards and your specifications.

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Friday, November 03, 2006

L-com Connectivity Products' Master Catalogs

L-com Connectivity Products Catalog (
L-com 2006 Master Catalog 2.0
Many customers have told us that our catalog is one of the best reasons to do business with L-com. Not only does it contain high-resolution, full color photographs of our products for easy identification, but it also contains over 90 tips, tutorials, diagrams, a helpful connector chart, and general connectivity information. The best part: its free!

Tip: How to Panel Mount a Gender ChangerIf you are an electrical engineer, IT professional, or otherwise involved in electrical connections, you should get this catalog just to have it. It makes a fine reference book and helps you to explain complicated connectivity subjects to people outside your department.

You can request a print catalog from L-com Connectivity Products, or you can also download .pdf file versions of the catalog. In October, L-com came out with it's second master catalog of 2006, which included quick RoHS compliant symbols to help isolate compliant parts. We're not stopping there, and hope to have another updated catalog out early in 2007.

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Wednesday, November 01, 2006

Coiled Cable Assemblies: Fiber Optic and USB

Coiled USB CableUSB and Fiber Optic Coiled Cable Assemblies (

One thing about cables: they are messy. They're often either too long, meaning you have to find a way to hide the slack or get it out of the way, or they're too short and you have to move things around to accommodate.

That's why coiled cables are so useful, especially in cases where they may be plugged in and out frequently or moved from location to location. For both USB cables and Fiber Optic cables, this can be a problem but for different reasons.

For instance, USB has a maximum length of 5 meters (about 16.4 feet). But, since you tend to move things plugged into a USB port (like cameras, mice, keyboards, etc), the flexibility to extend and contract the cable is very useful. L-com's coiled USB cables also have latching Type A connectors, so they won't fall out when the cable is pulled.
Coiled Fiber Optic Cable
Fiber optics, on the other hand, have almost no length restriction (you can run a single fiber cable several kilometers and still have connectivity). For that reason, most off-the-shelf fiber optic cables are pretty long. But when you're in a wiring closet and you need to patch fiber cords onto networking equipment, the ability to stretch a smaller cable and not have too much slack getting in the way is important.

L-com offers a selection of coiled cables available off-the-shelf, and we can custom build them.

Monday, October 30, 2006

L-com Audio/Video DVI Sub Panels (

L-com Audio/Video DVI Sub Panels

We just recently added a new member to our Universal Panel lineup, the USP2DVI. It has two DVI couplers pre-installed in it. These are technically DVI-I couplers, meaning that they have holes for the digital and analog pins on both DVI-D and DVI-A connectors (so, basically, they work with all three types of DVI connectors).

This panel joins the other pre-populated sub panels that
we carry. If you're not already familiar with our Universal Rack Panel system, the way it works is you can buy a 2U (3.5" high) rack frame with 6 holes cut in it, and these Sub Panels fit into those holes. So, you can make virtually any panel you want by mixing and matching sub panels into the frame.

Rack Panels are something we do well at L-com, and we're interested in custom rack panels as well. If you have a special panel you'd like us to build, give us a call or send an email and we'll see what we can do!