Lokking for antenna recommendation

hbq · 12-Jul-2011, 7:10 PM

Hi all, we started having OTA reception problems after adding a third tv in December and now that the leaves are out and summer weather is here.

The antenna set up is a very old UHF/VHF/FM antenna shaped like a Channelmaster Crossfire, but only about 5-6 feet long and about the same wide. It is mounted on pole about 10 feet above a story & a half house. We sit in a bit of a valley and the neighbors between us and the towers in Shorewood MN, have a yard full of tall spruce and other trees that block the path. The antenna is intact but the balun looks pretty weathered and the wiring is a bit rusty. The original twin lead was replaced many years ago with what looks like unlabled rg6, which runs about 40 ft to an unlabled 3-way splitter in the basement. The runs are about 10, 15 & 25 ft to two old tv's with converters and one newer HDTV. These runs appear to be made with unlabled rg6 also. There is another, smaller UHF antenna mounted below the main one, but it is not connected anymore. It is a solid bowtie shape with reflectors.

Channels 2.1,2,&4 are the weakest. If the tv's can find them they drop out intermittantly with or without the splitter. 41.1,2,3 are the next weakest. The VFH channels 9.1 and 11.1&2 are the strongest, with the rest of the UHF channels somewhere in between. With the splitter removed we can get45 intermittantly, even though it is at almost 90 degrees to the other towers.

I am considering replacing the balun & main cable to be sure it is quad rg6. But I am also wondering if I should just replace the antenna with a new one, perhaps even a multidirectional antenna to bring in 45 (not critical). Perhaps an amplifier would be useful as well. Here is the tvfool link[URL="http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d03d9f0e61b8860"] Thanks for any advice!

John Candle · 14-Jul-2011, 1:56 AM

http://www.tvfool.com/?option=com_wr...03d9f0e61b8860 . <-- As you typed it out , but did not make a active link by using the link box. Is this correct?? Click on the blue circle with the double link chain and this will open up the link box , you can then type the link information in there.

hbq · 14-Jul-2011, 4:18 AM

Clicking on the link in your reply seemed to work, but I'll try again.

http://www.tvfool.com/?option=com_wr...03d9f0e61b8860

hbq · 14-Jul-2011, 4:37 AM

I replaced the matching transformer and reception inproved somewhat. Playing with the aiming of the antenna, I am somewhat confused as to why two stations that are supposed to be at the same compass point, say KTCA and WFTC, have maximum signals in different directons (I don't have a compass, but it seemed that their maximum signals were maybe 20 - 30 degrees apart.) Are some antenna's of the same style much less directional than others?

John Candle · 14-Jul-2011, 5:42 AM

Three situations come to mind. #1 Tv antennas are very wide frequency band antennas and as such are a compromise design , Tv antennas have a lobe pattern and the lobe pattern is a little different at different frequencies/channels. #2 The transmitter may not be in the place that is indicated or might have been moved to a different location. #3 Multipath (reflected signals) might be the situation.

John Candle · 14-Jul-2011, 7:52 AM

I recommend a Winegard HD7694P outside on the mast. Put a distribution amplifier Channel Master CM3414 four way distribution amplifier inside the house. Aim the HD7694P at about 60 degree magnetic compass. Use all new RG-6 coax from the antenna to the distribution amplifier. From each output of the distribution amplifier , a coax goes to a Tv/converter box. Any outputs the of distribution amplifier that are not used should have a 75 ohm terminator so the system is balanced. The Tv stations in green are easy to receive with strong signal strength. The Tv stations in green are in one direction except KPXM UHF 40 ION Tv that is on the side of the HD7694P antenna. However the signal is strong and by turning the HD7694P antenna more in the direction of KPXM , I think it will be received with out having to much reduction in signal strength of the other stations. Here are places to buy Tv antennas and etc. , http://www.solidsignal.com , http://www.starkelectronic.com , http://www.amazon.com , http://www.3starinc.com

John Candle · 14-Jul-2011, 8:13 AM

Read and understand about , REAL Digital Broadcast Tv Channels , Virtual Digital Broadcast Tv Channels , Analog Broadcast Tv Channels , http://forum.tvfool.com/showthread.php?t=695. Here are some but not all free tv guides , http://www.zap2it.com , http://television.aol.com , http://tv.yahoo.com , http://tv.entertainment.excite.com , http://www.titantv.com , http://www.tvzap.com , http://www.canada.com/entertainment/...ion/index.html

hbq · 14-Jul-2011, 5:12 PM

Thanks for the reply! I've been trying to read up on this stuff and am curious why a distribution amplifier is recommended over a pre-amp on the antenna (or does the 7694 antenna include one?)

Also, should the coax be solid core and quad shielded?

John Candle · 14-Jul-2011, 6:45 PM

The reason I am recommending a distribution amplifier is the Tv stations are of moderate and strong signal strength in the green and yellow. 20 NM(dB) to 50 NM(dB). The signals are not weak so there is no need to preamplify.

GroundUrMast · 14-Jul-2011, 6:57 PM

RG-6 is solid core. The extra cost of quad-shield will not provide any tangible benefit. Quad-shield is used to protect the LNB signal out of a satellite dish from interference from terrestrial microwave sources, the link between the dish and satellite receiver are a closed system and uses frequencies assigned to various terrestrial services. OTA TV uses lower frequencies that are assigned exclusively the the OTA broadcaster, so there should be no conflicts from microwave ovens, Wifi or point-to-point microwave systems. Sources of interference strong enough to penetrate standard RG-6 shield will almost always be received by the OTA antenna, better coax shield can't stop that.

The DA is a good choice given the relatively equal signal levels together with a very good noise margin for the majority of the signals. You could use a high input preamp at the antenna... such as a Winegard HDP269 or Antennacraft 10G201. I'm not contradicting JC's suggestion though.

One or the other but not both. Rule of thumb: One amplifier can be too much, two amplifiers ARE too much.

John Candle · 14-Jul-2011, 7:36 PM

RG-6 copper center conductor is the best for signal transfer and quad shield adds another layer of shielding. The added layers of shielding is better because standard RG-6 has two shields , the aluminum that is bonded to the foam and the shield wires. If standard coax is streached or bent to many times the foil shield and the shield wires can break , this is not likley to happen with quad shield. As with any coax and connectors , look inside of the connector on the end of the coax and see if the shield and shield wires are pushed in toward the center conductor , if so then push the shield and shield wires away from the center conductor. Also to make the shield part of the coax more effective use a coax grounding block and ground. Can quad shield be used ? Well yes it can.