DH AZ-EL Manuale di istruzioni per l'installazione - Pagina 18

Sfoglia online o scarica il pdf Manuale di istruzioni per l'installazione per Cremagliere e cavalletti DH AZ-EL. DH AZ-EL 20.

To receive the optimum from your antenna, you must take time to fine tune the antenna. What are the antenna

adjustments? They are: make the front surface flat, be sure the feed looks at the center of the dish, and set the proper

focal length. You must also be pointed at the satellite and have the feedhorn skew properly adjusted.

Many of the adjustments are done without any measurement of the signal, and in fact require no signal at all.

The adjustment of making the front surface flat, adjusting the focal length, and aligning the feed will be done without

signal. You will use the strings and the back braces to make the dish flat, a focal finder and measure tape to align the

feedhorn to find center, and set the focal length using a measure tape to measure from dish to feedhorn. You will use a

satellite tool to locate signal in further steps of fine tuning.

We feel that you must use strings to assure the front of the dish is flat. The strings must be taut and run from

brace to the opposite brace at 180 degrees. A dish with 8 braces needs four strings. Do all adjustments with the braces

loose. The strings must touch at the center, if they do not, sight the dish from the side to see which braces should be

slightly adjusted to make the front surface of the antenna perfectly flat. CAUTION: do not over tighten the 8 bolts that

hold the dish to the ring as they can distort the dish.

The easiest way to assure yourself that the feedhorn is looking directly at the center of the antenna is to use a

Focal Finder (SEE PHOTO "A" BELOW) or to make a tool to assist in finding the center of the antenna. You can if no focal

finder is available, cut a 1" X 4" board to the length of the antenna's focal length. Held vertically against the feed it

should point at the center of the antenna, this will be true at the horizontal plane as well.

DH recommends using an AI Turbo S2 made by Applied Instruments or another tool such as a spectrum analyzer

to locate your satellite signal in order to complete the following steps:

Setting the Azimuth: To set the azimuth of the system you will use the base can and a tool to locate and

measure signal. Find a satellite signal using the AI Turbo S2 or another satellite tool that will show signal spiking. Any

signal strength will work. This is your reference point. Now you will go from bad signal to bad signal. From this reference

point you will move the antenna left of the reference point to see if the signal gets better or worse and right of the

reference point to see if this makes it better or worse. When you see the location of the base can for the best signal, you

will tighten down the set screws on the base can. (Special Note: It is best to make a mark on the pole and base can to

reference your starting point before making any moves with the base can. Re‐mark your base can and pole so that

you now know the location that is allowing the strongest satellite signal.)

Setting the Elevation

First elevate the antenna to the satellite and lock the elevation rod down. Tighten the U‐bolt on the tube and loosen the

bolts on the bracket that hold the tube. The tube now can be moved up and down by loosening and tightening the nuts

on either side of the bracket. You can make very small adjustments with this bracket, thus optimizing your signal.

Skewing the feedhorn: You will rotate the feedhorn; again going from left or right of the marked reference

location for your feedhorn, to find your strongest signal. Once you find your strongest signal tighten down into place.

Keep in mind when you are making these last "Additional Fine Tuning Techniques" very small moves will be

needed to make the best improvements in signal strength.

PHOTO A

Focal Finder to Locate

Center of Antenna

ADDITIONAL FINE TUNING TECHNIQUES

The fine tune adjustment for the elevation of the AZ‐EL Mount is very simple to operate.

AI Turbo S2 Made By Applied

Instruments

Page 12