Amplifier for OTA HDTV signals?

[adamhochman]

Hello,
I've been reading this site for a while and I'm incredibly impressed with all your knowledge. Hence, I'm turning to you to help me solve a problem which of course DirecTV cust svc was of no help with.

I recently had the HD Tivo installed with an OTA antenna put on my roof for the local HD channels. I live just outside Washington DC, about 5-8 miles from the local towers, so my reception should be fine (and I made sure the tech pointed the antenna in the right direction).

Yesterday, when first sitting down to watch HD on the locals, the picture/reception was horrible. It would go well for a few seconds and then freeze for a few seconds, sometimes pixellating (I guess that's what you call it) in the process. This happened continuously, such that it made impossible to watch.

In talking to DirecTV the tech couldn't really tell me much except to look into an amplifier or repeater from Radio Shack. Before I go that route, I wanted to ask if anyone knows if this will work or if there are any other solutions you know of?

I realize HD locals will be through the dish soon as DC is one of the first 12 markets. However, I'm not impressed with the HD package for $11 and wanted to just watch the HD locals for free until the HD package is good enough to justify the cost.

Thanks in advance for your help.
Adam

 

[charper1]

If you are correct, being less than 10 miles from the towers, you shouldn't need any amplification.

What make & model antenna do you have?

How is it integrated into your system?

 

[boba]

Go into the menu(directv button) and check the signal strength on the local channels(OTA) if your locals are below 70% you might be looking in the right place for your problem. At 5-8 miles from the broadcast towers a set of Rabbit ears should work. You could have reflected signals interfering with the signal from the broadcast towers an amplifier won't help a very directional antenna might help that problem. What did you have installed for an antenna?

 

[adamhochman]

Thanks for your comments. I looked into it a bit more last night. I have a good signal on all my network channels except Fox. I checked signal strength and it was pretty poor for Fox, but the others were okay.

The DTV tech installed the antenna-I don't know the make and model of it. As I recall it looked a bit like a waffle (for some reason i think he called it a pancake antenna). Having all the locals except Fox is okay, but not perfect (need my football on Fox). Any idea on how to tweak my system to get it (without having to call DTV)? Thanks again for your help.

 

[charper1]

Does it look something like this? Bowtie Antenna.

What is your location so we might be able to calculate you actual distances from the broadcast towers for each of the 4 majors.

 

[boba]

Thanks for your comments. I looked into it a bit more last night. I have a good signal on all my network channels except Fox. I checked signal strength and it was pretty poor for Fox, but the others were okay.

The DTV tech installed the antenna-I don't know the make and model of it. As I recall it looked a bit like a waffle (for some reason i think he called it a pancake antenna). Having all the locals except Fox is okay, but not perfect (need my football on Fox). Any idea on how to tweak my system to get it (without having to call DTV)? Thanks again for your help.

Only a guess but your description of picture freezing for a few seconds, strong signal strength, and a pancake antenna suggests a Multi directional antenna. This will accept signals reflected off buildings, water towers and other surfaces, you will have strong signal strengths but poor actual signals. Try a set of rabbit ears in a window that faces the broadcast towers connected to the satellite receiver instead of the roof mounted antenna. This will use the building to eliminate reflected signals and the low resistance of the glass will allow the desired signals to pass through.

 

[adamhochman]

Hello,
That bowtie antenna kind of looks like that. I live in Bethesda, MD (zip is 20814). I'm interested to see how far Fox is from me as opposed to the others, since Fox is the one really giving me problems.
I already tried rabbit ears, but since my TV is in a basement with no windows that didn't work so well.
Thanks again for your help.
Adam

 

[Hogarth]

You may wish to try an Attenuator.
Being only 5 miles from the towers may mean that your signal is too strong.

http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=15-1257
^^^ really easy and works great.

Turned all my signals from 63-70 to 93-100%.

H

 

[charper1]

I hope this table comes out looking OK.

Sign Dig Channel NET City/State Orientation Miles Assignment

WTTG-DT 5.1 FOX WASHINGTON,DC 172° 3.4 36
WBFF-DT 45.1 FOX BALTIMORE,MD 57° 33.5 46
WFDC-DT 14.1 TFA ARLINGTON,VA 176° 4.5 15
WRC-DT 4.1 NBC WASHINGTON,DC 176° 4.5 48
WUSA-DT 9.1 CBS WASHINGTON,DC 171° 3.8 34
WHUT-DT 33 PBS WASHINGTON,DC 172° 3.8 33
WMPT-DT 22.1 PBS ANNAPOLIS,MD 99° 26.5 42
WJLA-DT 7.1 ABC WASHINGTON,DC 171° 3.8 39
WDCA-DT 20.1 UPN WASHINGTON,DC 171° 3.8 35
WETA-DT 26.1 PBS WASHINGTON,DC 202° 7.8 27
WBDC-DT 50.1 WB WASHINGTON,DC 135° 5.0 51
WNUV-DT 54.1 WB BALTIMORE,MD 57° 33.5 40
WPXW-DT 66.1 i MANASSAS,VA 230° 19.2 43
WNVC-DT 57.1 IND FAIRFAX,VA 227° 10.9 57
WMAR-DT 2.1 ABC BALTIMORE,MD 57° 33.4 52
WJZ-DT 13.1 CBS BALTIMORE,MD 57° 33.4 38
WFPT-DT 62.1 PBS FREDERICK,MD 338° 21.0 28
WBAL-DT 11.1 NBC BALTIMORE,MD 57° 33.4 59

 

[adamhochman]

Thanks for the info above (the distances from the networks). Is there any way I can tweak my system to get the networks better using this info?

 

[charper1]

Get a compass and adjust (rotate) the antenna's orientation toward the desired result; FOX DC is oriented at 57deg from your zip; a fair bit away from the masses located between the 131deg - 202deg mark. More detailed info can be obtained at www.antennaweb.org You can even try to small directional antennas, one at 57deg and one at say 180deg and combine them.