Can't always get 2 local channels

jmk909er · 30-Jan-2011, 2:29 AM

I am in San Diego and have a homemade antenna (attached pic). My antenna is mounted on top of my roof and I am in a pretty flat area. There are 2 local channels that I only get sometimes, I get all the other local channels fine except for these 2:

KFMB-TV (CBS) Distance: 12 miles @309° Channel 8.1
KGTV (ABC) Distance: 12 miles @309° Channel 10.1

Sometimes these 2 channels come in fine and sometimes not at all, even if I go up and the roof and adjust to all angles.
Is there anything that I can do to improve the performance of this or is there a better antenna type that I should be using?

Here is my TV Signal Analysis Results:
http://www.tvfool.com/?option=com_wr...3cf4612058e624

mtownsend · 30-Jan-2011, 6:01 PM

Fixed link to your report: http://www.tvfool.com/?option=com_wr...3cf4612058e624

FYI, the reason you're having trouble with these two stations is because they are broadcasting on VHF frequencies (ch 2-13). Be sure to look at the "real" channel being used by each station. Your antenna is designed for UHF frequencies only (ch 14-69).

If you want to do a better job picking up the VHF stations, you can either add a VHF-only antenna to your current setup, or you can switch your antenna to a "combo" antenna that does both VHF and UHF.

Some good high-VHF (ch 7-13) antennas are the Winegard YA-6713 and Antennacraft Y5713. Either of these antennas can be combined with your existing antenna using a Pico Macom UVSJ or equivalent (this is a diplexor, which more appropriate for this situation than a typical 2-way splitter/combiner).

Some good "combo" antennas are the Winegard HD7694P and Antennacraft HBU-33. Either of these would be a nice "one antenna" solution for your situation.

jmk909er · 30-Jan-2011, 7:32 PM

Thanks for your reply, do you know of any DIY plans for a combo antenna?

Dave Loudin · 30-Jan-2011, 7:39 PM

Go to the OTA forum of digitalhome.ca. There's a sub-forum dedicated to antennas, one of which, the Grey-Hoverman, might be the one you need. Feel free to post your TVFool report there to get some advice.

GroundUrMast · 30-Jan-2011, 11:42 PM

Quote:

Originally Posted by jmk909er

Thanks for your reply, do you know of any DIY plans for a combo antenna?

Not a combination, but a stand alone VHF design... combined with the UVSJ mentioned earlier, you could expect some success.

http://forum.tvfool.com/showthread.php?t=1106

ADTech · 31-Jan-2011, 5:50 PM

A "combo" antenna is not appropriate for your location. You need a dedicated high-VHF antenna pointed towards 8 & 10's towers (north-west) and combined with your UHF antenna using the UVSJ as suggested.

jmk909er · 3-Feb-2011, 12:45 AM

Hey guy's thank you all for your help, I got some plans from http://m4antenna.eastmasonvilleweather.com/index.html and made a new antenna and it working like a champ. I can now pick up the 2 channels that were not so good before and am getting another channel that I did not get at all before. I used # 10 copper wire mounted on PVC and all the connections are soldered. I made the 9 1/2" x 9" antenna. Here are some pics.

John Candle · 3-Feb-2011, 4:47 AM

Wow you are doing very well. And all the connections are soldered , the conections will last a long time out in the weather. Having no reflector , the antenna receives 2 directions. As you have figured out by now , a reflector makes the antenna 1 directional and increases the reception in the 1 direction. And reduces reception from behind the reflector. The antenna with out the reflector receives from 2 directions and the antenna gain is less , but has the advantage of receiving 2 directions. Antennas work simlar to a light bulb. A bare light bulb sends out light all directions , a light with a reflector , reflects more of the light in one direction and this makes the light stronger.

John Candle · 3-Feb-2011, 4:59 AM

The down side of a antenna with out a reflector is - multipath. . The advantage of digital Tv tuners is the multipath correction that corrects multipath up to a certain point. In the 'old days' of Analog Tv - multipath was a real problem , it showed up as ghosts in the picture. . The extra tv channels are likely arriving from other directions to your 2 directional antenna.

John Candle · 3-Feb-2011, 5:11 AM

A satellite dish , the dish part is a reflector that reflects and focuses more signal to the antenna out front. . See how well the antenna will receive a satellite signal by it's self. Remove the the antenna from the dish , turn it around and point it at the satellite.

John Candle · 3-Feb-2011, 5:44 AM

Here is how to point tv antennas. http://www.kyes.com/antenna/pointing/pointing.html , Read and understand this about Real Digital Tv Channels and Virtual Digital Tv Channels and Analog Channels. http://forum.tvfool.com/showthread.php?t=695 The 2 directional antenna can be directed between digital channels 19 / 28 and 8 / 26 and will receive most all of those channels in those 4 directions.