ahlburuto
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« on: May 16, 2008, 08:07:03 AM » |
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Paano ba ito nasusukat? Papano mo malalaman na yun ang Db ng antenna mong ginawa?
BR
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« on: May 16, 2008, 08:07:03 AM » |
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rdpzycho
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« Reply #1 on: May 16, 2008, 09:53:10 AM » |
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computed siya, complex mathematics.  although may mga simulator. pwede ring mameasure using spectrum analyzer. ratio ng power sa location nung spectrum analyzer at nung power sa same location using an isotropic radiator (spherical radiation pattern). |
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"Keep on starting, and finishing will take care of itself."
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ahlburuto
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« Reply #2 on: May 16, 2008, 12:03:04 PM » |
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wala ata ako nun ah..... mas maganda kasing me idea ka dito, lalo na dun sa nag install ng antenna ng tv.
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zer0w1ng
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« Reply #3 on: May 16, 2008, 02:59:55 PM » |
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Gain, directivity and SWR of antennas can be simulated using "Numerical Electromagnetic Code" (NEC). See here http://www.si-list.net/swindex.html to download the software.   |
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rdpzycho
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« Reply #4 on: May 17, 2008, 01:27:31 PM » |
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yan nga yung software. thanks sir zerowing.
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"Keep on starting, and finishing will take care of itself."
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jctupazvi
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« Reply #5 on: May 17, 2008, 09:29:05 PM » |
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This is a good tip zerowing. How ever there are many versions in the website, which one is the best to use for Windows XP?
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ahlburuto
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« Reply #6 on: May 23, 2008, 05:52:24 AM » |
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salamat boss zer0wing..... alin kaya dito ang dapat kong idownload? dami pala nito eh.. br |
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zer0w1ng
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« Reply #7 on: May 23, 2008, 10:38:50 AM » |
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4Nec2 is the one I am using.
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ahlburuto
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« Reply #8 on: May 24, 2008, 01:50:32 PM » |
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in assembling tv antenna ba eh ilang dB b dapat ang gagawin mo?
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rommelpm
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« Reply #9 on: May 29, 2008, 04:27:50 AM » |
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Paano ba ito nasusukat? Papano mo malalaman na yun ang Db ng antenna mong ginawa?
for TV applications:There this an instrument call "DB meter" that measures RF signals of TV distributions. It also incorporates a spectrum analyzer and a small TV monitor. From experience, we measure the RF signal that is being delivered by the TV-headstation up to the TV-wall sockets. The following standards that we are using are as follows:signal path: TVHeadstaton------------> building RF amplifier------> splitter----------> TV wall socketRF signal from aerial antenna = 35-to-45dBuV (use boosters if below 35dbuV) RF signal output from headstation amplifier = 90-to-100 dBuV RF signal from output of building amplifier = 90-to-100 dBuV RF signal at TV wall socket = 64dBuV-to-80dBuV  |
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ahlburuto
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« Reply #10 on: May 29, 2008, 05:48:21 AM » |
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anung itsura po ng ganung dB meter?
thanks sa info
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rommelpm
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« Reply #11 on: May 30, 2008, 07:21:24 AM » |
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anung itsura po ng ganung dB meter?
thanks sa info
ito sample nang dB meter for Satellite and TV reception:  |
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rommelpm
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« Reply #12 on: May 30, 2008, 07:28:17 AM » |
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in assembling tv antenna ba eh ilang dB b dapat ang gagawin mo?
 dB level can range from 5-to-10 dB or more... (source: Kathrein ) |
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ahlburuto
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« Reply #13 on: May 30, 2008, 07:30:46 AM » |
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yun bang paggagawa ng antenna ng tv eh naaayon din sa lugar o location mo? like in our place here in batangas, what is the applicable antenna ba dapat ang gawin ko para masagap ko lahat ng vhf and uhf channel? at aun yung magiging elevation ng antenna?
br
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rommelpm
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« Reply #14 on: May 30, 2008, 10:02:49 PM » |
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yun bang paggagawa ng antenna ng tv eh naaayon din sa lugar o location mo?
Pag ma-bundok ang lugar ay naka "STACK" ang mga dipoles nito same when using Yagi. siguro alamin mo kung anong TV channel o frequency ang meron sa area nyo para yan ang magiging center frequency nang antenna mo...remember an antenna has to be tuned to the frequency you intend to receive. |
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ahlburuto
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« Reply #15 on: May 31, 2008, 06:18:17 AM » |
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Pano ko naman malaman kung anung TV channel o frequency ang gagawin kong center frequency ng project ko?
br
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rommelpm
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« Reply #16 on: June 03, 2008, 08:31:07 PM » |
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Pano ko naman malaman kung anung TV channel o frequency ang gagawin kong center frequency ng project ko?
br
You have to choose the middle frequency: say: chan 5 = 76-82Mhz chan 6 = 82-88Mhz chan 7 = 174-180Mhz chan 8 = 180-186Mhz chan 9 = 186-192Mhz chan10= 192-189Mhz chan11= 198-204Mhz chan12= 204-210Mhz to approximate the center freq to use: BW= 76-210Mhz f1=76 f2=210 fcenter= (f1 x f2) 1/2 fcenter = (76 x 210) 1/2 fcenter = 126Mhz this was how we calculate before as far as I can still remember |
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ahlburuto
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« Reply #17 on: June 03, 2008, 10:01:29 PM » |
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sa pang tanong, eh papano yung uhf channel? halimbawa kung mix ang vhf at uhf? papano computation nun?
salamat ulit sa info....
br
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rommelpm
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« Reply #18 on: June 04, 2008, 02:43:56 AM » |
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sa pang tanong, eh papano yung uhf channel? halimbawa kung mix ang vhf at uhf? papano computation nun?
You have to design a separate antenna for each band. Try mo i-check yung "ARRL antenna book" you'll find good infos. |
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ahlburuto
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« Reply #19 on: June 04, 2008, 07:32:54 AM » |
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ok bro.... thanks ulit sa mga info mo...
br
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December 22, 2010, 12:45:11 PM
