Join Date: Jan 2010
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I've been watching OTA TV since there were all 82 channels (2-83) reserved for TV stations, and DIY hobbies were still popular. The TV frequencies (wavelengths get shorter as frequencies get higher, BTW) ranged from the low VHF band to the high UHF band. Within this range of frequencies are three distinct bands: VHF-LO, VHF-HI and UHF.
Back then, UHF was kind of mystical because most consumer electronics designers had little experience in this band, and equipment quality varied widely. These days the roles are reversed, as UHF is widely used and lower frequencies' peculiarities have made them less desirable. Here's a very basic synopsis of the main qualities of the bands:
VHF-LO: Generally for line-of-sight use only. Long wavelength requires large antenna to work best. Good for long range reception, although TV frequencies were mostly immune from the interactions with the universe that made shortwave bands so much fun. Good point-to-point performance in forested areas. Poor penetration of buildings and other structures. Used to be preferred in LMR (land mobile radio) use for rural areas.
VHF-HI: Mostly for line-of-sight use only. Shorter wavelength more practical for building and vehicle mounting of antennas. Suitable although not ideal for longer range communications. Shorter wavelengths offer fair building penetration, especially at higher powers and/or close range. A compromise of the benefits and problems associated with lower and higher frequencies. Used to be preferred in LMR use for suburban areas. Still the band of choice for aeronautical communications and fire departments.
UHF: Strictly for line-of-sight use only. Even shorter wavelength most practical for hand-held, as well as other antenna mounting. Suitable only for line-of-sight communications. Excellent penetration into buildings, but poor performance in wooded areas. Can be made to perform well in all areas through the use of high mounted "look down" antenna/repeater infrastructure. Preferred in LMR for urban areas. Preferred for ATSC television broadcasting.
Satellite TV also uses different frequency bands in the SHF region and beyond. C Band was and still is used for network TV program distribution. It was used briefly for home reception, but is no longer supported for home use mostly. Every Satellite TV service in the US uses the Ku Band. The Ku Band's shorter wavelengths allows smaller antennas for a given amount of gain and spatial selectivity. (With the Clarke Belt as crowded as it is, it's often more important to be able to focus on one "bird" and reject its neighbors than it is to achieve enough gain and S/N ratio.
While consumer Ku systems are prone to fading with high levels of precipitation, there are many misconceptions about why this happens. Briefly, it's not related to any resonances in of water or its component elements. It's just that water is the most common form of matter to get in the way of a line-of-sight signal. This is exacerbated by the demand for smaller, cheaper and "less ugly" antennas, which must be mounted outside because they can't "see" through walls either.
Electrical discharges such as lightning often do interfere with TV reception of all kinds. This is because most electrical discharges produce the same kind of electromagnetic energy that TV transmission relies on. Needless to say, blotting out the organized signal with a random one will cause a loss of information.
You get what you pay for. For professional advice, pay the professional rate.