VSAT, Networking, and Hobby

I was on Ngurah Rai airport Bali on May 22th,2011. When in process of boarding to my plane, I was looking at a interesting color scheme plane beside my plane that I used to board. So, I get it photograph I can tell it interisting, because that color scheme I remember it used by Garuda Indonesia long time ago. Then, I search some answer why there is a plane of Garuda Indonesia use that color scheme. At last, I get information that this retro color scheme used for Garuda Indonesia new units of Boeing 737-800 NG. Nice move of Garuda Indonesia, to remind us what their painted color plane in the 1960s until 1980s.

There are many types for earth station antenna, which are : 1. Prime Focus Feed Most popular due to its excellent efficiency (approximately around 62%) Because of its relatively large surface, the prime focus antenna is less sensitive to small directional deviations and there is a better chance of receiving signals outside the normal footprint. Usually limited up to 4.5 mtr diameter Sometimes problem with OMT adjustment for "prima" Cross-Polar Isolation (CPI) characteristics Because of the LNB is mounted centrally, a lot of the incoming signals are blocked by the LNB on the way to the antenna surface.   2. Offset Feed Better efficiency due to reduction of Feed (and spars) "blocking" Simple to deploy, usually to Fly-away or Transportable SatCom terminals Much easier to adjust in achieving very accaptable Cross-Pol Isolation (CPI) Due to its simple construction, while satisfying the requaired ruggedness of Feed support, normally these are produced max ...

Now, let's me talk about measurement unit that used in telecommunication, especially in VSAT.  dB (deciBell) unit copes with logarithmic and relative parameter. dBm is a standard unit for measuring levels of power in relation to a 1 milliwatt (mW) reference signal. dBm and dBW related to "absolute" power/level. 0 dBm (=mW) means power of 1.0 mW dBm is similar to dB, or decibel , except that where dB is relative to the power of the input signal, dBm always relates or absolute to a 1 milliwatt signal (as measurement unit). A minus sign before the dBm indicates a loss and a plus sign or no sign at all before the dBm indicates a gain. A guide in this relative unit can seen below :  10 dB means 10 times than original   7 dB means 5 times than original   3 dB means 2 times than original   1 dB means 5/4 times compared to original   0 dB is 1X the original  -1 dB means 4/5 times compared to original  -3 dB means 1/2 times than original -10 dB means 1...

Hi everyone, now time for another kit of mine, Masurao (GNX-U02X)   This is customized design of MS built for Graham Aker (Mr. Bushido) by Billy Katagiri and his team, which Graham demand great speed and excellent melee combat capabilities As for Billy worked before for Union, this MS trully resemble MS Over Flag. The Masurao is powered by a GN Tau Drive and also capable of accessing a Trans-Am-like system (based on note of Professor Ralph Eifman) that allows it to fight on the same level as its rival 00 Raiser. This sharp snap-fit kit of Masurao will be fully articulated with polycapped joints upon completion. Includes a pair of GN beam sabers and optional hands (open hands and grip hands) (Hint : Graham Aker a.k.a Mr. Bushido voice actor is Yuuichi Nakamura also voice actor of Saotome Alto from Macross Frontier)    The horns at Masurao's head can move forward and backward   With unique sole   Equipped with two beam saber; Large beam saber named How...

Sun Outage (or Solar Outage) is a severe interference event generally resulting in the loss of satellite communications service caused by the physical geographical alignment of the sun, satellite and earth-station coming into a direct line. Look the picture above, let's assume that virtual orbit of Sun with position from A to N. When an Earth station and Satellite Communication is In-Line with the Sun position, then the Earth station receive heavy and very strong NOISE for Rx-path. This Sun Outage happens because Sun is the largest Noise Source with 'complete' Spectrum. Sun Outage will be experienced by Satellite communication twice on every year, which are in March and September for a few days, duration of approximately 10 to 20 minutes a day, starting from the most West Earth-Station. From the picture, Station A located in West of Station B, will have earlier Sun Outage (usually before noon) compared to Station B.

Intermodulation occur when the non-linearity of a device or system wth multiple input frequencies causes undesired otputs at other frequencies. In communication system (include in satellite communication), this means that signals in one channel can cause interference with adjacent channels. As the spectrum become busier and the channels become more tightly spaced, minimizing intermodulation distortion becomes more important. To measure this Intermodulation, we can combine two equal power signals with a set frequency spacing at the input of the device-inder-test DUT). The output spectrum will look like figure below ; The two largest signals are the amplified carrier signals, and the smaller signals, moving away from the carries in both directions, are the 3rd order, 5th order, and 7th order intermodulation products, respectively. The frequency spacing between all the signals is equal. The interest parameters here as follows : Carrier (C) : This is the power of the carrier signal i...

"When Terrestrial Communicatios Infrastructure is Damaged, Destroyed, or Overloaded, Satellites = Operability" Satellite communication are : High Survivable (Physical survivability and robustness) Independent of Terrestrial Infrastructure Able to Provide the Load Sharing and Surge Capacity Solution for Larger Sites Best for Redundancy : They add a Layer of Path Diversity and Link Availability Satellite Systems Perform Effectively When : Terrestrial infrastructure is damaged, destroyed, or overloaded Interconnecting widely distributed networks Providing interoperability between disparate systems and networks Providing broadcasting services over very wide areas such as country, region, or entire hemisphere Providing connectivity for the "last mile" in cases where fiber networks are simply not available Providing mobile/transportable wideband and narrow-band communications Natural disasters or terrorist attacks occur. Satellites are the best and ...