Unamplified gain is specified at –15 dB for channels 2 to 6, –5 dB for channels 7 to 13 and zero dB for UHF channels. Its top performing indoor antenna is the SS-3000. Winegard's Indoor Antenna Model SS-3000 Winegard has taken steps to improve the VHF performance of its indoor antennas and offers some interesting options. How many indoor antennas, other than rabbit ears, have you seen with a linear dimension greater than 30 inches? There are smaller indoor antennas without additional elements (directors or reflectors) that are able to receive VHF broadcasts, such as the RCA ANT-1500, which can't match the "gain" of a set of rabbit ears without amplifiers. The combined length of the two elements ranges from about 31.75 inches at channel 7 to 26.375 inches at channel 13. Given the space constraints on top of the TV set, it will be very difficult to obtain more signal from one of the fancier passive indoor VHF antennas than what you'd obtain from a set of rabbit ears, assuming they adjusted to the correct length for the VHF channel being viewed. Noise can come from many sources in the house-appliances, microprocessors (in computers and other devices), video displays, and the increasingly popular energy efficient compact fluorescent lamps. The two major issues affecting indoor VHF reception are low gain antennas (usually "rabbit ear" dipoles") and noise. They must do this with effective radiated power capped well below that of UHF TV stations-160 kW versus 1,000 kW. According to the analysis Bill Meintel presented at the IEEE Broadcast Technology Symposium last October, VHF stations need a field strength close to or stronger than that of UHF TV stations for indoor TV reception, (see "2008 IEEE Broadcast Symposium in Review," Dec. My focus will be on high-band VHF channels, as few stations will be using low-band VHF channels post-transition. This month, I'll look at reception options for VHF TV, both indoor and outdoor, new Gray-Hoverman antenna developments, and take a look back at some VHF antennas that worked well in the 1950s. Fortunately, rescanning solved many complaints, but not all. Some have already made the transition and found viewers that were receiving DTV on UHF previously had problems with reception on VHF channels. Many TV stations with high-band VHF analog channels are moving their DTV transmissions to those channels after analog is shut down on June 12. A digital signal would produce the same effects as a weak signal: either a clear ghost-free picture, or loss of audio and video, depending on the severity of the multipath. Again, this may be annoying but is still viewable.
An analog signal would appear with a "ghost" image, which is a slightly displaced and faint duplicate of everything in the picture. However, if the digital signal was too weak, it could cause the audio and video to cut in and out or disappear altogether.Īnother example is multipath, wherein some of the TV signal bounces off a tall building or other structure and arrives slightly later than the direct path signal.
In contrast to this, a slightly weak digital signal would still be sharp and clear. For example, a weak analog signal would appear on the TV screen as a "snowy," or grainy, picture, which may be annoying, but is still viewable. Digital TV is far superior in quality and clarity than analog TV, but a weak signal can sometimes cause problems with reception.