TVJack

Jim1348

I think that the time to suggest it is now. That having been said, I am using a CM-4228 (old version) in the attic above my detached garage. I have only two VHF channels and the rest are all UHF. While I don't recommend it because of potential problems with MPDI (Multi Path Distortion Interference), it can be done. I suppose this is a case of "do as I say, not as I do." For whatever it is worth, I am 20 miles from the broadcast towers. If they do have the room for an inside antenna and are prepared to take the time to get it right, it can be done. It can also be frustrating and it is possible that the MPDI will be too problematic. The other usual recommendations apply, too, of course. For example use good low loss feedline RG-6 or better. Keep in mind, however, that RG-11 is thicker and less flexible than RG-6. Usually I don't recommend amplifiers either, but I am feeding multiple receivers, so I am using an amplifier. I also will say that, and it almost goes without saying, working with digital is different than analog.

Piggie

Welcome.

Go to TV Fool
Put in their address, and use 10 ft for a height to approximate the signal either high in the room or low on the roof.

Then there will be a link in bold at the top of the page, copy and paste it back here.

__________________
The more I understand, the less I know.

FOX TV

TV antennas "WILL ALWAYS WORK BETTER" mounted outside than one used inside. It is a terrible thing that was done to consumers by promoting indoor antennas for the Digital TV transition. All of the DTV testing was done with antennas erected at 30 feet, and then the NTIA and the CEA, along with the NAB are all guilty in this regard by promoting indoor antennas or "Rabbit Ears' in all of the DTV answers commercials we saw for so long.

Indoor TV antennas did not all of a sudden become magic, with the ability to defy physics just because the signal contains digital information. On the other hand, a lot of the reception issues I used to deal with before the transition, suddenly slowed to a few calls a week after our station "Maximized" our transmitters output power. Transmitter output power increases were allowed by the FCC to help with power density of UHF signals to help justify all of the misleading promotion that was done before the transition, and to help indoor antennas work better.

Not all stations had enough infrastructure (Reserve transmitter power, antenna power handling and feed line capacity) in place to take advantage of "Facility Maximization", which the FCC is still allowing to date in some areas.

We went from 500KW to 625KW, and it drastically helped reception issues in our area from one of our transmitters, and the other site was completely rebuilt with a new antenna and a power level of 925 KW. We cannot quite do a megawatt without running another tube which would double our power usage for only 75KW more power output on a thousand foot tower.

Moral of this reply is that OUTDOOR ANTENNAS WILL ALWAYS WORK BETTER THAN ONE USED INDOORS, PERIOD.

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Some people think the Bush administration is responsible for the DTV transition !!

SWHouston

Jack,
How nice it is of you to want to help your folks out, and asking questions here, is the first step toward getting them good reception.

First...
What Piggie said was very important, you MUST know what Channels are available at their location, to even start the evaluation process. Going to TVFool and making a Chart on their "specific" location, is the only way to get even close to an accurate evaluation and subsequent recommendation.
I'll disagree with Piggie to some extent, that being to use...
5 Ft, for an Indoor (top of TV) operational height.
15 Ft, for a Roof Mount on a Single Story house, and
25 Ft, for a Roof Mount on a Two Story house.

You'll actually need to run two separate charts, 1 for inside, and 1 for outside, to see if you actually will be doing yourself any good, by mounting the Antenna on the Roof. One thing I'll say up front, is that it ALWAYS is better to have a Rooftop installation, but, you need to run a couple charts anyway. Just to make sure.

Secondly...
How thoughtful it is that people will come online here, and tell how a given antenna works for them. BUT, that's them, for the type, height and location that they are commenting on, and is NOT where you are interested in locating their (your folks) Antenna.

Once having seen the Chart, there are several people on the Forum here, who can comment on an Antenna that's just right for your folks specific location and reception needs.

When linking to TVFool, be sure to scroll down to the bottom of the first page, and enter the Height of the installation. If you want to print out the Charts for viewing, you must save them to your computer as stated, and print them out from it.

Please look above the Chart Graph and Channel List (on the second page), for the bold link, which you should copy and paste into your post here, where we can take a look at the chart with you.

Have a good Day !
S.W.