HDTV Forum

I've always had poor reception at my house on most channels with analog. With digital it's worse since the signal isn't just bad, it drops out altogether. I'm about a mile fom the 8 or so high-power transmission towers in Portland Oregon. I've always assumed it's signal overload but the digital signal strength display on my DTV tracks with the performance -- that is, it shows low strength on the channels that are poor, and higher strength on the good ones. Can I depend on that display to tell me the truth? One other factor is that there are tall fir trees between me and the antennas, and I'm down a pretty good angle from where they are (tops of the tallest antenna is 2200' and I'm at 700'). Could the trees or the angle be the problem?

I've tried everything from no antenna connected to rabbit ears to a high-gain roof antenna with a signal amplifier, and the best I've been able to achieve is with a Rube-goldbeg getup, arrived at just by trial and error, which consists of a coax going up to my roof connected to a preamp that's strapped to the mast, but NO antenna -- the little flat connector wires are just poking up into the air (silly looking!) and the amplifier at the bottom end is NOT plugged in.

This is driving me nuts. How can I tell what is REALLY the problem and how to solve it? And please don't say "get cable" - I do realize that's an option (duh).

Good morning & hello ' rando ' -

You seem to have at the least two very important problems or "issues' ??

As you already posted - that very severe elevation difference between the top of those TV Towers compared to that of your antenna(s) IS an enigma that must be seriously considered.

BUT - while faint, snowy, ghosty analog reception has been your situation up to now - DTV must be 100% perfect in it's display / audio - - - or - - - simply ZERO / a blue screen !

First, "carefully" go onto your roof to "see" those TV Towers - - - "IF" there IS no position or place from which you CAN clearly see those ( 8 ) tower antennas WITHOUT looking through those leaves in Summer time - stop ! You will NOT be able to enjoy 100% dependable, DTV reception!

After the above visual "test" and with a successful conclusion - - Consider a unique, fully-adjustable yet very secure "quadrant" angle mount @ a proper Band antenna.

By that is meant one such as a Channel Master # 5646 { rather than it's exact Twin # HD3016 @ $20 more ! } for TV Markets using both TV Bands - - - - or - - -

A DB-2 for all- UHF only Markets.

Try:

www.solidsignal.com

for either unit and always use Quad RG-6 coax in an uninterrupted length from that antenna connection directly to the TV and / or Converter !

At the solid signal web site, just select " 35 feet " at their Quad Coax station and they'll make it custom with excellent weather-proof compression "F" connectors free, / complete and / or simply get a 50' stocked, prepared coil from another excellent web store here . . .

http://www.monoprice.com/products/produ ... 1&format=2
under $8 !!

eli

DB-2 . . . http://www.solidsignal.com/prod_display.asp?prod=TD-DB2

CM 5646 . . . . http://www.solidsignal.com/prod_display ... d=ANCM5646

A { p.s. } . . . try setting that "quadrant mount" at about 15 or 16 degrees "up angle" from the usual horizontal.

Rando,

Clearly you have special circumstances! If you can find a professional antenna installer with a spectrum analyzer they will be able to figure out what is going on and possibly recommend a solution. The difficult part will be finding one with a spectrum analyzer but that piece of equipment will provide the information required to stop guessing.

About all we can do is guess and who knows, we/you might get lucky.

the digital signal strength display on my DTV tracks with the performance -- that is, it shows low strength on the channels that are poor, and higher strength on the good ones. Can I depend on that display to tell me the truth?

No. The display won't show you if the signal is overloaded as just one example. Signal meters on consumer gear are fuzzy wuzzy when it comes to providing useful information making them highly limited for tackling reception problems.

Being this close to the towers all your stations should have plenty of signal gain if not too much. So what does make sense is multipath signals that are partially or fully canceling the primary signal which you might perceive as a loss of signal or weak signal and your receiver will definitely see and report it as lower in level.

Antennas for your application are going to be low gain but the nature of their design makes them omni-directional which goes directly against a multipath problem. High gain antennas are way more directional but you don't need the gain of the design, just the multipath rejection that makes them highly directional. You could try that and put an attenuater on it to reduce signal strength. Ultimately, I don't know of a commercially available antenna design for this application. Many would say get cable or satellite.

One of my clients who was responsible for a cable system for an Atlanta college had your kind of problem and cooked up this home brew design.

Antenna - extreme multipath problem
viewtopic.php?t=6914

He provides a link for the project and you also get to see the power of a spectrum analyzer in action.

Thanks! This has been most helpful.

Rando