Saturday, December 11, 2010

Rabbit Ears

Ever since we moved up to the mountains, I have used some rabbit ears that I bought at Radio Shack for broadcast channels--this model, it appears.  It seems as though a few months after all the local television stations went digital that my rabbit ears were not pulling in signals quite as well--and some channels just stopped coming in at all. 

When the entire process was analog, there was no dividing line between "you have signal" and "you don't."  You might have a crisp clear signal, or you might have one of an infinite number of progressively uglier images, until you could not tell if you were watching television or random noise.  With digital television, there is a point where the A-to-D converters throw up their little electronic hands in disgust and say, "I don't know what this is, I'm not playing anymore."  At that point, our digital TV converter box just tells you that it can't get a signal.  Before you completely lose the signal, you start to get interesting artifacts--blotches of color because individual delta frames are being dropped, and the infamous "Max Headroom" stutter sound effect.

My guess is that the reason my rabbit ears stopped pulling in some channels is that the television stations figured out that they were broadcasting more power than they needed for the 99% of their audience that was down in the flats--and cut the power slightly.  Hence, the reduced ability to get some stations.

Since we dropped Dish Network in favor of Netflix, we have been watching a bit more of the broadcast channels, and the nuisance of not getting some channels--and the problems of not quite getting some channels finally moved me to action.  I was thinking of removing the satellite dish, and replacing it with an external antenna.  There is already RG-59 coax running from the satellite dish to the TV--so this would be a simple process.

My concern was that the coax cable run produces its own signal losses--and over the distance involved, rather a substantial loss.  Would it be enough to make up for the gain from an external antenna?  Yes, but how much of a gain?  And how much work was I prepared to spend installing the external antenna?

I went down to Radio Shack last night.  While talking to the helpful salesperson, and contemplating how I was going to get that big box into the Jaguar, she mentioned that since I was getting many stations okay with rabbit ears, perhaps I would benefit from amplified rabbit ears.  This unit, model 15-254, looks quite similar to what I already had--but the box promised 22 dB of gain over standard rabbit ears.  What the heck, they look awful, but there was no installation work, so I bought them.

At first glance, I didn't see a difference on the channels that were coming in fine--but now, the channels that did not come in were coming in without problem.  The digital TV converter box has a signal strength meter, so I decided to use that to compare the results.

With the standard rabbit ears, aimed as optimally as I could get them, the signal strength meter showed 46%.  (What is that a percentage of?  I have no idea.)  With the amplified rabbit ears, the figure was now 80%--and I did not need to try and tune the antenna directionally to get various channels.

If you are giving up cable or satellite, as many people are, before you spend a lot of money on an external antenna, consider whether amplified rabbit ears might solve your problem with the expense and aggravation of a traditional external antenna.  I am well out of Boise, with some low mountains in the way, and these solve my problem just beautifully.

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