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Old 22-Sep-2010, 6:31 PM   #6
mtownsend
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Join Date: Dec 2009
Posts: 632
I wouldn't expect much on channel 5 from a C5 antenna. I'm guessing that the low-VHF gain is quite low like most other channel 7-13 antennas.



For both low and high VHF coverage, you can use an antenna like the Winegard HD-5030 (large) or Antennacraft CS600 (small).

It's also possible to combine a low-VHF and high-VHF antenna through a HLSJ, and then combine a UHF antenna through a UVSJ. I don't see any particular advantage to having separate hi/lo VHF antennas, but special circumstance might warrant such an approach.

It's always a big gamble trying to pick up channels *through* a building. To get to the channels on the other side of the building, I would strongly urge getting the antenna on the roof or on the other side of the building.

If the user insists on picking up the stations *through* the building, then there's no way of knowing how much signal the building will block/reflect/absorb. They may end up needing a larger, higher gain antenna, or it may end up not working at all. My gut feeling is that rabbit ears probably won't be good enough to pick up channels 10 and 12 reliably through the building unless they happen to get a lucky bounce off a nearby building or their own building is unusually "transparent" at VHF frequencies.

To put a few numbers to these ideas... Rabbit ears in an ideal dipole configuration will get close to 0 dBd gain. In reality, people are more likely to see closer to around -2 dBd gain. The small VHF Yagis will typically see between +2 and +5 dBd gain. The large VHF Yagis may get as much as +5 to +9 dBd gain. The losses caused by the building can be all over the place, but in most cases, it is roughly in the range of about 5 to 30 dB of loss.



I think my initial recommendation would be to get the antenna on the roof or hang two antennas on opposite side of the building. If the user can give each antenna a clear view toward each of the main transmitter clusters, then I would point a CS600 to the south-west, and a DB2 or DB4 (for added gain yet still a wide beam width) aimed north-north-east, half way between channels 51 and 23. Combine the antennas through a UVSJ or a dual-input pre-amp.
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