Best of the ISP-Lists

Do I Need a Laser Scope?

From strobe lights to military hardware, members of the ISP-Wireless list have a variety of methods for ensuring that a customer gets broadband RF reception. For some equipment, however, the best method is just to read the manual.

[February 3, 2001]

On the ISP-Wireless list in January, WB inquired,

"What tools are you using to aim a CPE antenna?"

A number of respondents shared their favorite methods:

[BR suggested] "Eyes, one set of binoculars, clear day…"

[AS advised] "Try GPS."

[CW countered] "Use a compass!"

[JT suggested] "Slowly rotate the antenna until you achieve a link. After you get a link, rotate the antenna slowly until you lose the link, then mark the mast at the spot that you lost it. Then rotate the antenna the other direction until you lose the link that way. Mark the mast. If you rotate the antenna to center of the two marks, you should be pretty close."

[MO added] "Check out the military surplus houses and look for a signaling mirror, a small rectangular piece with a 'hole' in the middle (the glass has a clear spot that you sight through to aim the reflection in the general direction). They have directions on the back and are real easy to use. I used these in the early '80s to line up a 57-mile link, mountaintop to tower. Got us in the ball park to get signal and then fine tune with meter. They say one can see the flash from one of these at 100+ miles. It was originally designed as a signaling device for rescue."

[MS noted] "Most radios have a built-in tool for this. I move the antenna around till the radio gets the strongest signal. If you need something visual, just get a yellow strobe light and put it on the tower with one of those devices that lets you turn it on or off via a phone call. Turn it on, do your site survey or aiming, then turn it back off. You'll know it's yours since everything else way up in the air is red or yellow. Don't leave it on, as it'll confuse the heck out of people…"

KS offered a more unusual solution:

"Go to a gun store and get a small laser sight. They run about $40-50. Put it on the tower antenna pointed at the horizon. Go to the CPE site and use night vision binoculars, available for about $250-300. Look for the beam, follow it back to the tower, and aim away. It's quite amazing. It looks like a very bright thread hanging in midair. If it's cloudy, you could get away with regular binoculars because you'll be able to see the red laser beam passing through the clouds if they are low enough."

Others strongly disagreed with the laser idea:

[AS countered] "That doesn't sound too reliable. I think you'd need a pretty darn powerful laser to be able to see it. 3000 yards tops. I think you'd lose it."

[BM agreed] "Let's be serious… climbing on a roof at night? Let's talk safety: you could fall through a skylight, fall off the end of the roof, trip over vent pipes, etc. Besides, the laser sight is not useful over a mile or so."

Still others noted that many manufacturers now offer the solution as part of the package:

[JT offered] "With most Breezecom equipment, all you need is a laptop."

[PL added] "With the new DS outdoor product, you don't even need a laptop. The outdoor unit has a built-in dB signal meter. Each bar on the meter represents 4 dB."

[DL observed] "The Sony satellite dishes have an LED that flashes faster as the signal gets better. Very easy to zero it in."

—End

   

Related articles:
	[Jan. 24, 2001]	Part 2: Beware, Thieves!
	[Dec. 8, 2000]	FHSS or DSSS