Monday, July 22, 2013
What Are Short Range Radio Devices?
Short range radios are highly cost effective and very reliable communication devices. These devices vary from each other depending on their features, cost and size etc. Not all the short range radios suit everybody. There are few factors that should be considered before choosing a radio for best usage. So here are some of factors you should consider before choosing for a best short range radio.
Frequency Range:
Frequency is the primary and the most important issue that should be considered when selecting a radio. Most of the radios come with a digital display which shows the frequency of the radio. Few radios are less expensive as they have an analog "slide rule" frequency which doesn't reveal the precise frequency of the radio. Make sure to get a radio with good frequency range for better usability. Here are the frequency ranges for few of the famous radio devices available.
Note that VHF stands for Very High Frequency, and UHF stands for Ultra High Frequency.
Motorola: Frequency Range: VHF: 136-174 MHz; UHF: 403-470 MHz.
Kenwood: VHF: 136-174MHz; UHF: 400-430MHz, 440-470MHz
Icom: VHF 136 - 174 MHz UHF 400 - 470 MHz
Vertex Standard: VHF: 134-174MHz; UHF: 380-450 MHz, 450-512 MHz
HYT: VHF: 136-174 MHz; UHF: 400-420 MHz 440-470 MHz
TaitNet: 136-174MHz/400-520MHz
Antenna:
Almost every radio comes with a built in telescopic antenna however, there are radios that have external ones too. Built in antennas are good for some extent, however, external antennas give better reception than that of inbuilt antennas. When the radios are used inside a building or a room that has steel frames then the output quality of radios goes down.
Built in antennas give great results to pickup international broadcast channels and they are not so effective for fainter signals. Radios with external antenna jacks can catch these fainter signals. Buying a radio with external jack as well as built in antenna is always a good idea to catch both international as well as fainter signals.
Selectivity options:
One should always consider the number of selectivity bandwidths available in a radio. Few radio receivers have very few bandwidths. But few have wide number of selectivity bandwidths. Radios with narrow selectivity bandwidths have less interference on adjacent frequencies.
So, before choosing a radio, you should prioritise the requirements and features you wanted. These radios are generally come handy and flexible to working people who needs to stay connected with each other. Generally these radios can communicate with in a range of 3 miles. These radios are low cost communication devices that have no services charges. Motorola, Kenwood, Icom, Entel, Vertex Standard, HYT, Tait are some of the best radio devices one can consider for short range communication.
Applications:
These radio sets are extensively used in Construction companies to communicate with working engineers inside the site. Police department also uses these devices to communicate with local offices to prevent crimes. Manufacturing companies, retail companies also often use these devices. They also come handy in public events like wedding, receptions for local communication between personals.
The Maintenance of Earth Station Antenna
The simple maintenance for earth station antenna can reduce the antenna failure probability and extend the antenna life, so a regular and complete antenna maintenance planning will be helpful for the antenna normal operation.
Appropriate maintenance planning is a kind of commercial insurance. Check the completion of the whole structure and ensure the normal operational capability by the simple and low-cost surface maintenance; Check the electrical performance, and comply with the maintenance regulation in the manufacture operational maintenance manual so as to reduce the occurrence of antenna failure.
Our company summarize many years experience of production and maintenance of Earth Station Antenna and combined with the feedback of many customers from all over the world to create the daily inspection manual. We hope this manual can help the antenna users.
1. Surface Maintenance
Check the complete paint surface and electroplating surface, as well as fixed structure. First rub the rust spot on the electroplating surface by metal wire brush or abrasive paper, and then coat a layer of zinc-rich coating or a layer of rust inhibitor which will not require the complete clearance of the rust.
The user should repair it even if only a little of the finish peeling or color fading, or it will become more and more serious. And the user must accord with the antenna manufacturer regulation for the paint surface and coating specification, because the wrong coating method will affect the signals accept. For example, the dark-colored antenna reflector surfaces can absorb easily, and so it can give rise to high temperature, which can cause the signal distortion. Too much lead paint can make the signals loss by attenuation or scattering.
2. Antenna Fasteners
The nuts, bolts, rivets and other fasteners in the installation will be affected by atmospheric effect or internal corrosion. Regardless of any corrosive components and the error installation will be found in the routine maintenance. At this time the users should tighten the loosen nuts and replace the lost, rust and corrosive components.
With the American Society for Testing and Materials Institute A325 or other occasions of friction components, the user must replace the loosen or corrosive components, because in the process of re-tightening it will make the fasteners get the reuse term. Also the corrosive A325 metal parts should be replaced not be tightened.
Often there are pins inserting in the pivots of the adjustable antenna bracket. Check if the activities of these jointing are flexible, and lubricate the oil by a grease-gun with oil jet. If the antenna rotates not flexibly, the user should replace the pin.
Check the metal fasteners on the antenna reflector and back structure. Except American Society for Testing and Materials Institute A325 must be replace, the user can tighten the loosen parts. The lost, rust and corrosive fasteners should be replaced. These check processes are also suitable for the operational platform when assembling the antenna, as well as assisting the reflector and reflector support.
3. Ground
No matter how high the buildings, the antenna and bracket should be grounded to prevent the lightning strikes. Inspect if the mechanical of grounding system and no mechanical connection are connected.
Analyze if the grounding connection is connected by the earth loop impedance instrument. According to the test results the user can decide the cost of the excavating work. Check if the mechanical grounding parts are rust, corrosive or loosen. Replace the rust and corrosive fasteners so as to limit the inductance value.
Unload the grounding sharp dogleg head on the antenna or bracket. According to the test results determine whether adopt auxiliary grounding measures.
On the place which can use the step auto-tracking device, check whether the pedal is level by a longitude and latitude stadia. If the pedal is not level, it can affect the antenna position calculation. Adjust the level nut under the base plate to make the antenna keep level.
If the anchor bolts prevent to adjust the pedal level, adjust it while fixing the antenna. After adjusting, check if the cement sealing of the antenna foundation and anchor bolts crush and shift. If it is damaged, even a little, also should be repaired. After adjusting, the controller should be programmed again.
If some devices are mounted in the antenna box which is on the back of the reflector, check if there is accumulated water or a large number of termite or rodent infested in the box. Repair or seal the crack, even if it is little. If the user do not care about it, ants, mice and other animals will cause incredible losses.
4.Cable and connector
Intermediate facility link cable transmits the signal between the antenna and computer room. Check if these cables are damaged. If there is something wrong with insertion loss, the user should test and check whether the cables need to be replaced or be repaired.
When repairing the cables, the user can splice them in the new position, but it can cause some signals attenuation. With Time Domain Reflector check the position of the broken line. With a voltage meter check all the cables and connectors of the electrical properties and connectivity.
The coaxial cable with a bend head in excess of the minimum bend radius should be tested. After testing if it does not comply with the cable specification, it should be replaced.
Ensure the I F L cable and other cable support and routing (positioning and bending radius) accord with the manufacturer technical requirements. Replace the lost, rust and corrosive backup supports. When supporting I F L cables, it is better to use stainless steel cable link or cable clamp than the plastic rope. Stainless steel link should be used to fix the elliptical waveguide. Inspect the cable manufacturer recommendations.
If the stainless steel link or clip is not useful, and the cable manufacturer have not specified any stainless steel link or clip, in this case the user can only use black nylon rope, the white or bright-colored rope is easy to be fragile in the sun. The user should always check the cable rope, because the nylon rope is easy to be loosen than stainless steel clip.
Check the I F L connectors and connection parts. Replace the connectors which appear fracture line, line antihypertensive or other problems. If I F L cables come from the catheter, the user should check the catheter and other connectors. Check if the catheter input is strict, if there is accumulated water in the catheter, the water will freeze, which will squeeze the cable broken.
Check the feed combiner flexible elliptic waveguide line, if it is damaged, replaces it. If the system inflation pressure is not enough, corrosion can change the signal-to-noise ratio to affect the signal or cause the antenna stop working.
5. Shutdown Maintenance
Some maintenance work should be done when the antenna do not stop working, but most of the maintenance work need to be done after the antenna stop working. For example, when moving the antenna or cut down I F L line, the user must shutdown the antenna. First check the antenna azimuth and elevation bracket. Look if there is some fracture and hardening phenomenon for the protection cover of the support bracket, if need, replace it.
For the motorized antenna or the antenna which points to a Satellite for a long time, sometimes those antennas also need to be moved. This step can be considered as part work of daily check in each year. Have another regulation. When doing the maintenance, according to the maintenance period table of ANT our company clear the support screw, and lubricate the oil.
If the user finds the support bar moved on one position and was wear, it should be adjusted. When rotating the antenna, ensure that mechanical limit switch can stop after antenna motor finishes the planned journey. The limit switch malfunction can make the antenna rotate continuously until it will be damaged or hit with other objects.
Check the operational maintenance of the Antenna Manufacturer,note that the special requirements and suggest when to lubricate the oil or when to inject the oil for the azimuth, elevation, polarization and other motors. Antenna motor wire box should be dust-free and moisture-proof and all the connection should be fixed. If due to improper maintenance of the equipment, our company will not be responsible for warranty.
6.Maintenance Record
Keep a maintenance record. At the beginning of installing the antenna, leave a record with date and photos. Then maintain once, keep a record once, so as to keep a complete antenna system record.
In the antenna valid life keep a record of antenna pattern so as to find the phenomenon of the system signal dropping.
If it is required to shut down the antenna and do the maintenance, you should better arrange the maintenance work when the antenna does not work or within one hour at off-peak period. If the antenna can not stop work, transfer this antenna work to another temporary earth station antenna.
7. About our company
Our company is a global supplier of communications systems equipment and services. Major markets are earth station antennas - which includes Satellite communication antennas, receive only antennas, flyaway antennas.
Appropriate maintenance planning is a kind of commercial insurance. Check the completion of the whole structure and ensure the normal operational capability by the simple and low-cost surface maintenance; Check the electrical performance, and comply with the maintenance regulation in the manufacture operational maintenance manual so as to reduce the occurrence of antenna failure.
Our company summarize many years experience of production and maintenance of Earth Station Antenna and combined with the feedback of many customers from all over the world to create the daily inspection manual. We hope this manual can help the antenna users.
1. Surface Maintenance
Check the complete paint surface and electroplating surface, as well as fixed structure. First rub the rust spot on the electroplating surface by metal wire brush or abrasive paper, and then coat a layer of zinc-rich coating or a layer of rust inhibitor which will not require the complete clearance of the rust.
The user should repair it even if only a little of the finish peeling or color fading, or it will become more and more serious. And the user must accord with the antenna manufacturer regulation for the paint surface and coating specification, because the wrong coating method will affect the signals accept. For example, the dark-colored antenna reflector surfaces can absorb easily, and so it can give rise to high temperature, which can cause the signal distortion. Too much lead paint can make the signals loss by attenuation or scattering.
2. Antenna Fasteners
The nuts, bolts, rivets and other fasteners in the installation will be affected by atmospheric effect or internal corrosion. Regardless of any corrosive components and the error installation will be found in the routine maintenance. At this time the users should tighten the loosen nuts and replace the lost, rust and corrosive components.
With the American Society for Testing and Materials Institute A325 or other occasions of friction components, the user must replace the loosen or corrosive components, because in the process of re-tightening it will make the fasteners get the reuse term. Also the corrosive A325 metal parts should be replaced not be tightened.
Often there are pins inserting in the pivots of the adjustable antenna bracket. Check if the activities of these jointing are flexible, and lubricate the oil by a grease-gun with oil jet. If the antenna rotates not flexibly, the user should replace the pin.
Check the metal fasteners on the antenna reflector and back structure. Except American Society for Testing and Materials Institute A325 must be replace, the user can tighten the loosen parts. The lost, rust and corrosive fasteners should be replaced. These check processes are also suitable for the operational platform when assembling the antenna, as well as assisting the reflector and reflector support.
3. Ground
No matter how high the buildings, the antenna and bracket should be grounded to prevent the lightning strikes. Inspect if the mechanical of grounding system and no mechanical connection are connected.
Analyze if the grounding connection is connected by the earth loop impedance instrument. According to the test results the user can decide the cost of the excavating work. Check if the mechanical grounding parts are rust, corrosive or loosen. Replace the rust and corrosive fasteners so as to limit the inductance value.
Unload the grounding sharp dogleg head on the antenna or bracket. According to the test results determine whether adopt auxiliary grounding measures.
On the place which can use the step auto-tracking device, check whether the pedal is level by a longitude and latitude stadia. If the pedal is not level, it can affect the antenna position calculation. Adjust the level nut under the base plate to make the antenna keep level.
If the anchor bolts prevent to adjust the pedal level, adjust it while fixing the antenna. After adjusting, check if the cement sealing of the antenna foundation and anchor bolts crush and shift. If it is damaged, even a little, also should be repaired. After adjusting, the controller should be programmed again.
If some devices are mounted in the antenna box which is on the back of the reflector, check if there is accumulated water or a large number of termite or rodent infested in the box. Repair or seal the crack, even if it is little. If the user do not care about it, ants, mice and other animals will cause incredible losses.
4.Cable and connector
Intermediate facility link cable transmits the signal between the antenna and computer room. Check if these cables are damaged. If there is something wrong with insertion loss, the user should test and check whether the cables need to be replaced or be repaired.
When repairing the cables, the user can splice them in the new position, but it can cause some signals attenuation. With Time Domain Reflector check the position of the broken line. With a voltage meter check all the cables and connectors of the electrical properties and connectivity.
The coaxial cable with a bend head in excess of the minimum bend radius should be tested. After testing if it does not comply with the cable specification, it should be replaced.
Ensure the I F L cable and other cable support and routing (positioning and bending radius) accord with the manufacturer technical requirements. Replace the lost, rust and corrosive backup supports. When supporting I F L cables, it is better to use stainless steel cable link or cable clamp than the plastic rope. Stainless steel link should be used to fix the elliptical waveguide. Inspect the cable manufacturer recommendations.
If the stainless steel link or clip is not useful, and the cable manufacturer have not specified any stainless steel link or clip, in this case the user can only use black nylon rope, the white or bright-colored rope is easy to be fragile in the sun. The user should always check the cable rope, because the nylon rope is easy to be loosen than stainless steel clip.
Check the I F L connectors and connection parts. Replace the connectors which appear fracture line, line antihypertensive or other problems. If I F L cables come from the catheter, the user should check the catheter and other connectors. Check if the catheter input is strict, if there is accumulated water in the catheter, the water will freeze, which will squeeze the cable broken.
Check the feed combiner flexible elliptic waveguide line, if it is damaged, replaces it. If the system inflation pressure is not enough, corrosion can change the signal-to-noise ratio to affect the signal or cause the antenna stop working.
5. Shutdown Maintenance
Some maintenance work should be done when the antenna do not stop working, but most of the maintenance work need to be done after the antenna stop working. For example, when moving the antenna or cut down I F L line, the user must shutdown the antenna. First check the antenna azimuth and elevation bracket. Look if there is some fracture and hardening phenomenon for the protection cover of the support bracket, if need, replace it.
For the motorized antenna or the antenna which points to a Satellite for a long time, sometimes those antennas also need to be moved. This step can be considered as part work of daily check in each year. Have another regulation. When doing the maintenance, according to the maintenance period table of ANT our company clear the support screw, and lubricate the oil.
If the user finds the support bar moved on one position and was wear, it should be adjusted. When rotating the antenna, ensure that mechanical limit switch can stop after antenna motor finishes the planned journey. The limit switch malfunction can make the antenna rotate continuously until it will be damaged or hit with other objects.
Check the operational maintenance of the Antenna Manufacturer,note that the special requirements and suggest when to lubricate the oil or when to inject the oil for the azimuth, elevation, polarization and other motors. Antenna motor wire box should be dust-free and moisture-proof and all the connection should be fixed. If due to improper maintenance of the equipment, our company will not be responsible for warranty.
6.Maintenance Record
Keep a maintenance record. At the beginning of installing the antenna, leave a record with date and photos. Then maintain once, keep a record once, so as to keep a complete antenna system record.
In the antenna valid life keep a record of antenna pattern so as to find the phenomenon of the system signal dropping.
If it is required to shut down the antenna and do the maintenance, you should better arrange the maintenance work when the antenna does not work or within one hour at off-peak period. If the antenna can not stop work, transfer this antenna work to another temporary earth station antenna.
7. About our company
Our company is a global supplier of communications systems equipment and services. Major markets are earth station antennas - which includes Satellite communication antennas, receive only antennas, flyaway antennas.
Tips on Aligning Your Satellite Dish or Antenna for Better Reception
If your satellite TV or antenna reception periodically breaks up or your receiver keeps losing the signal and going into search mode, the first step is to check the dish or antenna alignment. Strong winds or heavy snow loads can knock your dish out of optimum position. Here are a few tips for checking and adjusting alignment of your satellite dish, which also work for antenna problems.
Using A Signal Strength Meter
By far, the easiest way to check your dish alignment is with a signal strength meter. A signal strength meter is an easy to use device that is connected between the dish and the satellite receiver. Satellite Signal Strength meters range in price from under $20 to nearly $400 for a professional meter. To use a satellite signal strength meter you need the meter, a short antenna stub cable, wrenches for the cable connectors and the dish alignment bolts and access to the dish.
The procedure is simple. Disconnect the antenna cable from the dish. Attach the stub cable between the dish and the meter connection labeled LNB IN or FROM LNB. Connect the cable from the receiver to the other side of the meter. Turn on the satellite TV system and tune to one of the stations you're having difficulty with. If your meter has a voltage display, it should read between 13 and 18 volts. If the signal strength reading is off the scale, adjust the input to a mid-range reading with the adjustment knob on the meter.
Satellite dishes are adjusted both vertically and horizontally. Loosen either the vertical or horizontal adjustment bolts. Adjust the dish for the maximum reading on the meter, then tighten the adjustment bolts. Repeat the procedure for the other direction. If the dish mount is not perfectly level it is advisable to repeat the alignment procedure several times to achieve the optimum adjustment. If you still have trouble with your picture, check for trees or other obstacles blocking the signal. Another cause of an erratic signal can come from a failing in-line filter that is used by some satellite TV providers.
Built In Strength Meters
Another procedure involves using the satellite receiver's built-in signal strength meters instead of an in-line meter. The receiver's meters can be accessed through its Setup or Info menus. This procedure is best performed with one or two assistants to watch the on-screen meters and relay information to the one doing the adjustments. Set up your access to the dish. Obtain the proper size wrenches to use on the dish alignment bolts. Turn on your satellite TV system. Access the receiver's built-in meters using the Setup or Info menus. Loosen the vertical or horizontal adjustment bolts. Adjust the dish position to achieve the highest signal level. Your assistant will have to relay this information from the ground. Tighten down the adjustment bolts. Repeat the procedure for the other direction. Again, if your dish mount is not perfectly level, it pays to repeat the entire process several times to ensure the best possible alignment.
Using A Signal Strength Meter
By far, the easiest way to check your dish alignment is with a signal strength meter. A signal strength meter is an easy to use device that is connected between the dish and the satellite receiver. Satellite Signal Strength meters range in price from under $20 to nearly $400 for a professional meter. To use a satellite signal strength meter you need the meter, a short antenna stub cable, wrenches for the cable connectors and the dish alignment bolts and access to the dish.
The procedure is simple. Disconnect the antenna cable from the dish. Attach the stub cable between the dish and the meter connection labeled LNB IN or FROM LNB. Connect the cable from the receiver to the other side of the meter. Turn on the satellite TV system and tune to one of the stations you're having difficulty with. If your meter has a voltage display, it should read between 13 and 18 volts. If the signal strength reading is off the scale, adjust the input to a mid-range reading with the adjustment knob on the meter.
Satellite dishes are adjusted both vertically and horizontally. Loosen either the vertical or horizontal adjustment bolts. Adjust the dish for the maximum reading on the meter, then tighten the adjustment bolts. Repeat the procedure for the other direction. If the dish mount is not perfectly level it is advisable to repeat the alignment procedure several times to achieve the optimum adjustment. If you still have trouble with your picture, check for trees or other obstacles blocking the signal. Another cause of an erratic signal can come from a failing in-line filter that is used by some satellite TV providers.
Built In Strength Meters
Another procedure involves using the satellite receiver's built-in signal strength meters instead of an in-line meter. The receiver's meters can be accessed through its Setup or Info menus. This procedure is best performed with one or two assistants to watch the on-screen meters and relay information to the one doing the adjustments. Set up your access to the dish. Obtain the proper size wrenches to use on the dish alignment bolts. Turn on your satellite TV system. Access the receiver's built-in meters using the Setup or Info menus. Loosen the vertical or horizontal adjustment bolts. Adjust the dish position to achieve the highest signal level. Your assistant will have to relay this information from the ground. Tighten down the adjustment bolts. Repeat the procedure for the other direction. Again, if your dish mount is not perfectly level, it pays to repeat the entire process several times to ensure the best possible alignment.
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