soulmata
07-20-2007, 10:28 AM
When it comes to CPE cost, lower is always better. Invariably this means at one point in time choosing a plastic enclosure over a metal one, as the drop in cost can be considerable. They are also often easier to work with, being more pliable and easier to fit with different types of pigtails and mounts.
Unfortunately, a plastic enclosure can be your nemesis when it comes to stable installs, for much of the same reasons. I take the position that, if possible, you should never use a plastic enclosure - and always opt for an aluminum one instead. In the long run, the cost offset will be outweighed by the enormous benefits you gain from a metal enclosure.
This is coming only from my experience and opinion.
Some of the benefits a metal enclosure has over a plastic enclosure include:
1) Superior resistance to the weather: You will find, over time, that the metal enclosures have a better time of surviving harsh environments, particularly if you live in an area with a lot of rain. Plastic enclosures are more prone to swelling or distorting in the heat, or are easier to damage seals with during an install. A metal enclosure is unlikely to fade even in the harshest of weather. With aluminum enclosures that are coated, rust is almost a non-issue - even if oxygen and moisture got through the coating to the aluminum underneath, once aluminum rusts on the surface it does not penetrate any further. This may seem counter-intuitive, as usually plastic is easier to seal - unfortunately when you are dealing with plastic attached to metal parts, such as an N-Type pigtail, it becomes easier to damage your enclosure. A metal enclosure combined with a proper sealant will do better for you.
2) Superior resistance to external interference. The thicker metal enclosures offer a built-in shield against rogue RF, which can be especially troubling if your install is in a noisy area. On hilltops, for example, where many other people might be broadcasting, you want to minimize any potential interference. While you'll still have interference at the antenna, reducing it at the radio helps. Simply due to the nature of metal, you will have much higher attenuation due to the enclosure, with its ability to reflect or refract the majority of the RF coming into contact with it.
3) Easier grounding and better static protection. When it comes to protecting your radios and your radio boards (particularly with how sensitive newer products are to static discharge), a metal enclosure is the best bet. Assuming your board is properly mounted, a metal enclosure will give you a shield against static buildup and other forms of EMI. Overall it will make it easier for you to create protected and properly grounded systems, assuming you need to ground.
The longer you deploy CPEs, the more you will find that the odds of a plastic enclosure causing an issue with your install rise. It is hard to give you accurate figures because I work with a small company. However, I will say that every board which has come back from the field with a dead ethernet port was always inside a plastic enclosure.
Not to say metal is perfect - there are drawbacks, such as higher cost and a more difficult install - but when it comes to radios housed externally I will never again use plastic.
Unfortunately, a plastic enclosure can be your nemesis when it comes to stable installs, for much of the same reasons. I take the position that, if possible, you should never use a plastic enclosure - and always opt for an aluminum one instead. In the long run, the cost offset will be outweighed by the enormous benefits you gain from a metal enclosure.
This is coming only from my experience and opinion.
Some of the benefits a metal enclosure has over a plastic enclosure include:
1) Superior resistance to the weather: You will find, over time, that the metal enclosures have a better time of surviving harsh environments, particularly if you live in an area with a lot of rain. Plastic enclosures are more prone to swelling or distorting in the heat, or are easier to damage seals with during an install. A metal enclosure is unlikely to fade even in the harshest of weather. With aluminum enclosures that are coated, rust is almost a non-issue - even if oxygen and moisture got through the coating to the aluminum underneath, once aluminum rusts on the surface it does not penetrate any further. This may seem counter-intuitive, as usually plastic is easier to seal - unfortunately when you are dealing with plastic attached to metal parts, such as an N-Type pigtail, it becomes easier to damage your enclosure. A metal enclosure combined with a proper sealant will do better for you.
2) Superior resistance to external interference. The thicker metal enclosures offer a built-in shield against rogue RF, which can be especially troubling if your install is in a noisy area. On hilltops, for example, where many other people might be broadcasting, you want to minimize any potential interference. While you'll still have interference at the antenna, reducing it at the radio helps. Simply due to the nature of metal, you will have much higher attenuation due to the enclosure, with its ability to reflect or refract the majority of the RF coming into contact with it.
3) Easier grounding and better static protection. When it comes to protecting your radios and your radio boards (particularly with how sensitive newer products are to static discharge), a metal enclosure is the best bet. Assuming your board is properly mounted, a metal enclosure will give you a shield against static buildup and other forms of EMI. Overall it will make it easier for you to create protected and properly grounded systems, assuming you need to ground.
The longer you deploy CPEs, the more you will find that the odds of a plastic enclosure causing an issue with your install rise. It is hard to give you accurate figures because I work with a small company. However, I will say that every board which has come back from the field with a dead ethernet port was always inside a plastic enclosure.
Not to say metal is perfect - there are drawbacks, such as higher cost and a more difficult install - but when it comes to radios housed externally I will never again use plastic.