Dealing With Trees & Tall Buildings...begging for a recom.

[Geeg]

Latitude: 46.824169 °, Longitude: -100.782772 ° and zip code 58501. I have 4 TV sets with convertor boxes on each one and the longest cable run is about 75 feet to the fartherest TV. The splitter to the TVs is right off of the booster cable I have a large (10+ foot mast) VHF/UHF antenna with a 26 Db Radio Shack antenna booster on the antenna which is located in the house attic now and have lots of cut-outs in reception, but especially bad with any kind of weather, or during certain times of the day. The towers are only about 20 miles away! The neighbor to the south has several 30 to 40 foot trees in our path as well. We actually noticed the reception improved some since the leaves fell off. However, our biggest obstacle is a large (greater than one block wide) 17 story tall concrete building about 2 blocks away, but very directly in our line of sight towards the tower locations for our area which are 175 to 177°. I think all of the local stations are now UHF. I am contemplating a large directional UHF antenna either in the attic again, or on top of the single story house, but want to have a large enough antenna to overcome the obstacles, especially the trees next door and the tall building, and of course with enough Db to feed 4 TV sets. Thanks for any recommendations!

[tigerbangs]

Your CBS station is on channel 12, so a UHF antenna probably wont work to get that channel. It would help to know what kind of antenna you are currently using: I can identify them by their phorograph in most instances. I would also be concerned that the signal strengths of the local stations may be too great for the preamplifier that you are using: you may be a candidate for a distribution amplifier or a high-input preamplifier like a Winegard HDP-269.

If you watch the signal quality meter on your tuner, do you see wild fluctuations while the program is breaking up? That is a sure sign of major multipath distortion, and we may need to take heroic measures if the dropouts are that bad. If you dont see wild fluctuation in signal quality on the meter, then you may have a preamplifier issue. Let us know which way things go.

[sregitz]

I do have wild fluctuations in the signal strength meter during drop outs so I am interested to hear specifics on the heroic measures you mentioned in your last post. Thanks.

[Geeg]

I did some experimenting since my original post. This is a link to a picture of the big Phillips antenna I have:
http://www.savinglots.com/lotprod.asp?item=MANT901
Checking signal strength on the Converter Boxes with this antenna & Radio Shack 26 db booster is about 55-75% on all channels, but if signal strength goes below 50%, I get no signal at all at the TV. As originally posted I have drop-outs with signal strength to 0% at times, and the dropouts and scrambled screen get very bad during any kind of wind or bad weather.
Just to try different things, I made this homemade antenna: http://uhfhdtvantenna.blogspot.com/
Surprisingly, it works almost as well as my original setup-Actually, I think even a little better in some locations. I tried several locations around the yard & found the best seemed to be on the detached garage in the back yard, but from that location there seems to be less tall trees in the direct path toward the towers. Signal strength with this homemade gadget varies from 28% to 76% on various channels and locations without a booster, but I don't loose reception until signal strength gets below 28% which seems odd cuz with the booster I loose it below 50%. However, I still have occasional drop-outs to 0% signal strength at times, and especially bad when there is any kind of weather. I tried numerous locations and varying direction of the antenna. The best signal strength was always directly toward the towers, even though that is also directly toward the 17 story large concrete State Capital building less than two blocks from us. I also tried hooking up certain TVs to this gadget thinking it was the most watched TV giving more of a problem but that didn't seem to change much, I had close to the same signal strength on each TV. Thanks for any suggestions or help you can provide!

[Geeg]

Sorry, I forgot to address the "wild fluctuations" you asked about! When I have good signal strength, the normal fluctuations vary by about 7 to 15 percentage points, with occasional short drops 30 points or more & to 0 at times. But when there is any wind or weather, when the signal is borderline (30-50% with the homemade gadget) the fluctuations in signal strength are much wider and down to 0 lots more frequently, same as with the antenna and amplifier. One other puzzling thought, this homemade gadget looks like it should be UHF only, but it also brings in CBS channel 12(which I think is VHF) with the same signal strength as the other channels?? Thanks again!