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Old 21-Oct-2011, 7:56 AM   #2
GroundUrMast
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Join Date: Oct 2010
Location: Greater Seattle Area
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Let's be conservative and use Comscope's RG-11 specifications. At 200 MHz the loss would be 1.68 dB per 100 feet, at 700 MHz, the loss is stated as 3.27 dB per100 feet. The loss at the end of 26 hundred feet will be 43.68 dB at 200 MHz and 85.02 dB at 700 MHz.

Yes, you would need several inline amplifiers with slope equalizers to deal with the approximately 40 dB difference in loss between the upper and lower frequencies. An example of the type amplifier needed might be the Pico Macom PIDA-1000 which would need to be specified with the correct equalizer and power supply (I'm only illustrating the basic concept, not recommending the PIDA-1000). Presuming the PIDA was compatible with the cable chosen, three or four would be needed to deal with the losses indicated above. The noise figure of the PIDA-1000 is specified as 5 dB... four of theses in series will drastically reduce the available noise margins of all the signals. Only the signals with NM values of 20 dB or above would survive the trip down the line. (Note the list price of the PIDA-1000 is over $600 each.)

The number of amplifiers could no doubt be reduced if you opted to use 1/2" hard-line which would have lower loss than RG-11.

More expensive options would include cable TV head-end components that would receive the OTA-ATSC signal and then shift the frequency down into the low VHF range. The least expensive solution I have come across retails at around $750 per RF channel. Example: Holland HPH-860AD which has fairly stringent requirements for the incoming off air signal level and noise margin. I expect that for most individuals such equipment is cost prohibitive and also well beyond their skill level.

Regarding two antennas bending the signal... There does not appear to be nearly enough signal in the air to make a 'passive repeater' function. A quick glance at a link budget calculator indicates the 1/2 mile path would add more than 90 dB additional path loss. Even with two 20 dBd gain antennas back to back, you'd be left with at least a 50 dB hit. I'm fairly certain the FCC would require you to license the system if you added any type of amplifier to boost the signal through the air.


If your uncle is willing to use a home theater PC, take a look at this idea: http://forum.tvfool.com/showthread.php?t=1286
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Last edited by GroundUrMast; 21-Oct-2011 at 9:34 AM.
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