Some HD Questions Answered

[R.D.P.]

I just recently spoke with Best Buy.  They told me and my mother that the drop outs some are experiencing (Like us) are going to occur, because the analog and digital signals are fighting each other in the airwaves.  Once the analog shuts down, then the signal issues with the digital will be solved.

Now if you want to split off many boxes to one antenna, forget that.  Just learned that you won't be able to.  Discovered that while reading from an instruction book, that came with a new antenna my father recently purchased.

Want more boxes, then shell out more bucks for more antennas. 

This same instruction book also said, that you can only use 70 ohms line, the line must be less than 100 feet and can't touch the antenna.  (Exception being, to screw the wire into the antenna)

My only hope is that Direct TV will add our local channels to their mix. (Montgomery Alabama area) If they don't then their subscribers, in my market, will be forced to use multiple antennas and boxes to drag in our locals.  What a shame it is.

For those that had questions, hope these answers will help.  I'm still learning more about HD TV, like everyone else is.  Hope my info will assist someone, in some way.

R.D.P. <><

 

[tripinva]

Wow. Better not tell my dad that, we've got three boxes, plus two analog TVs still without boxes, all going to the same antenna. And all the UHF digitals work great.

Plus I've got the antenna line into my room split four ways. Still works on both digital receivers I have here.

- Trip

 

[R.D.P.]

How did you do that and are you using an older antenna?

We tried to split off the two boxes, to one outside antenna but it didn't work out.

Had an old antenna and it broke. Got a new one and then tried that again but it still didn't work out.

R.D.P. <><

P.S.The info I shared, came with the new HDTV antenna we recently purchased.

 

[tripinva]

Antennacraft Y5-2-6 (for low-VHF) combined with Winegard PR-8800 (for UHF). The former is brand new, the second is about 5 years old. They're combined outside and then the single coaxial cable runs inside to a CM7777 amp, gets split two ways. One goes to dad's sound room, the other into a four-way splitter. Signal from there runs all over.

- Trip

 

[pabsungenis]

All stuff and nonsense. Never believe anything anyone in Best Buy tells you; they don't know an antenna from a hole in the ground.

If you have weak signals in your area, yes, splitting an antenna will lessen the signal, but you can get away with putting a distribution amplifier in place, instead of multiple antennae.

"Signals fighting each other?" Unless you have an analog signal on a first adjacent to a digital signal, or a distant analog signal on the same channel that is somehow bleeding or E-skipping in, the signals can't "fight each other."

You should use a 75 ohm line, but in my old house I got great reception (with my TiVo Series 3) off a 40 year old roof antenna with its original 300 ohm line running from the antenna to the basement. All I did was add an in-line amplifier. And that run was much more than 100 feet.

You might actually want to turn the gain on your amp DOWN a little bit; with digital signals, a too-powerful signal can be as deadly as a too-weak one. Adjust and experiment.

 

[R.D.P.]

The fighting each other statment came from Best Buy.  The other statements came from a book, which was included with our new Phillips HDTV Antenna, we got at Wal-Mart.

I still have so much to learn.  For those that are helping me, thanks for your kind assistance.

...And yes, I live in a rual area, 50 miles west of Montgomery Alabama. 

R.D.P. <><

P.S. Most of the Montgomery Alabama TV stations, have their towers located east and south of the city.  The exceptions are Channels 8 and 29, which have theirs west of there. (Yes I can get those two channels)  Amazing that I can get WSFA Channel 12 and their tower is located south of Montgomery, near the Crenshaw County line and I'm at least 70 miles from there. 

 

[tripinva]

I remembered seeing your name around and thought you knew what was going on--I thought your first post was sarcastic! =X

In some areas, you'll have problems with analogs and digitals fighting, but it's certainly not most stations. Given the market you're in, I can't imagine it's a major problem. Looking at your post in the Alabama forum, I see you're working with the Montgomery stations--it's a mess down there, with most of the stations at very low power. Only 8, 12, 26, and 29 are at full power in your market (45 is close to full power though), everyone else is either at low power (20, 22, 32) or not on at all (67). Things should get better for you next year when everyone powers up.

- Trip

 

[kenglish]

Any "fighting" they do will be due to just too darn many signals in the air..not whether they are analog or digital. Too much signal, whether it's due to a few too-strong signals, or too many signals overall, will overload a tuner....and will, even more likely, overload an amplifier. So, maybe they're "half right".

Here at work, we've devised a test.....
Buy a 6 dB attenuator "pad" (you can use two 3 dB pads in series) for about $1.10.
Once you have a good signal, put the pad in line at the receiver (or converter box) input, and see if you still get good reception. A tiny bit of pixellization/dropout (or, a bit of garbled audio) is OK. That means you have sufficient "headroom" to handle varying weather conditions, or the (usually "daytime only") power-down of transmitters for tower maintenance work (we put everybody, TV and radio, to about 1/4 power when people have to climb the towers).

You can also try the pad in line to see if you just have too MUCH signal (that's assuming the signal is bad before you attenuate it). This only works, though, if you can attenuate the signal prior to the first point where it gets amplified...so, "amplified antennas" are going to be a problem. Best way to troubleshoot those, is to telescope the rods inward (lowering their sensitivity), or stand in front of them and block some of the signal.

When you have waaaay too much/too many signals, like in the City and suburbs, a preamp is often worse than no amp at all. That's when you need to call a pro...someone with proper test gear, like spectrum analyzers, or Digital signal analyzers (that show the actual data impairments). Often, they can fix it with inexpensive filters or RF traps, but it takes proper tools to find the problem and tune it out. Otherwise, you can mess around with it forever.

Passive (un-amplified) splitters on an outdoor antenna setup are usually fine for city/suburb use....there is often "more than enough" signal for a 2-way or 4-way split. And, that split may even be enough to prevent tuner overloading. But, especially with cheap splitters, you may find that the un-used ports need to have terminator resistors used on them. Cheap splitters usually have poor isolation between outputs, and a non-used cable or non-terminated port can cause ugly reflections that affect the frequency response, creating additional multipath (beyond what the particular tuner can compensate for).

 

[N_D_Radioguy]

Remember that, whether it's a retailer like Best Buy or a manufacturer like Phillips, their goal is ALWAYS to sell more antennae.

Any "information" they give is is meant to steer you toward spending more and has nothing to do with providing an accurate answer to your question.

The answer: do your own homework and experimentation [that includes swapping ideas in a forum like this].

 

[kenglish]

Amen!

 

[DJKraze]

Any mention anywhere about combining 4 different antennas, that's what I have.