Where to amplify

brianccarr · 17-Aug-2013, 7:10 PM

I just installed an Antenna at my parents home. I mounted on the chimney and and ran the coax cable to a three way splitter. Two tv's connect to the splitter with a fairly short run and receive all channels pretty strong. The third tv is located pretty far from the splitter and is not receiving all the channels due to a weak signal I believe from the long run. Should I install an amplifier after the splitter for this tv. Any advice on where the amplifier should be and a recommendation of a brand and model would be appreciated. The installed antenna is a RCA ANT751.

Thanks

GroundUrMast · 17-Aug-2013, 7:18 PM

It would be helpful to see the TV Fool Report for this location.

Generally, the best location for an amplifier is ahead of the loss. So 'at the antenna' is generally the ideal location.

You have many choices when picking an amplifier. Preamplifiers are usually intended to mount outside, on the mast at the antenna. Distribution amplifiers usually are not intended for mounting in the weather. The reason I ask for your TVFR is that some will be excellent in weak signal applications but won't be able to handle strong signals.

brianccarr · 17-Aug-2013, 8:32 PM

Thanks, here is the TVfool report

http://www.tvfool.com/?option=com_wr...46aef1569cfff6

GroundUrMast · 17-Aug-2013, 9:21 PM

A Channel Master CM-3410 distribution amplifier, between the antenna and splitter would be my suggestion.

brianccarr · 17-Aug-2013, 10:03 PM

Thanks. I will give this a try.

17-Aug-2013, 10:06 PM

Aim the ANT751 at about 318 degree magnetic compass direction.

Use a Old School magnetic compass.

Here is how to aim antennas , http://www.kyes.com/antenna/pointing/pointing.html.

Install a Winegard , LNA-100 'Boost' amplifier.

Install the LNA-100 in the coax line between the antenna and splitter.

The Best Practice is to install a amplifier before any signal losses that occure after splitters.

The Best Practice is to install a amplifier before any signal losses of long lengths of coax.

Reason: amplifier 'Do Not Pull Signal' through splitters and 'Do Not Pull Signal' through coax and amplifiers 'Do Not Pull signal from antennas'.

Amplifiers , Amplify and 'Push Signal' through coax and splitters.

_______________________

The ANT751 is a small antenna.

Small antennas receive less signal.

Bigger antennas receive more signal.

Receiving more signal means more signal strength will be in the system from the start.

More signal strength at the start is the best.

GroundUrMast · 18-Aug-2013, 12:12 AM

Go all the way... make it an LNA-200 which is apparently the weather proof version of the same amplifier. With the preamp head at the antenna, you get the maximum benefit from amplification.

Thanks again to Pete Higgins: http://www.highdefforum.com/local-hd...100-boost.html

brianccarr · 20-Aug-2013, 2:57 PM

I ordered the Winegard LNA200. I figured go all the way and take no chances. The closest TV to the splitter is getting all channels with at least 70% strength so I figure the antenna is big enough. The second tv is fine. Just the long run to a tv down to the far end of the house is the problem. Getting two channels just fine but not any others. Hopefully the LNA200 will do the job. One other question. Has anybody ever used the compass on an iphone? I tried it but I'm wondering if I may not be pointing the antenna just right. What I ended up doing is just turning the antenna with someone shouting out to me when the picture came in. Thanks for all the help.

GroundUrMast · 20-Aug-2013, 4:36 PM

Your method of final aim check & adjustment is the best option, though a real compass would no doubt put you closer than the unreliable iPhone virtual compass.

My experience with the iPhone 'compass' is that it's accurate to +/- 180°

I have yet to see it point north.

brianccarr · 20-Aug-2013, 9:57 PM

One other thought I wonder about. The long run back to the end of the house that is giving me a problem is using RG59 Coax leftover from an old Dish install. Would an upgrade to a different coax make a marginal difference? I also used this leftover cable to run from the antenna to the splitter. Thanks

GroundUrMast · 20-Aug-2013, 11:28 PM

Back in the days when the majority of TV was broadcast in the VHF bands, RG-59 was adequate. It's not too lossy at lower frequencies.

RG-59 is an unusual type of coax to find in a satellite system. It lacks the shielding that should be used in that application. RG-59 will have roughly 1.5 dB more loss than RG-6 for each 100' when used for UHF. The difference just gets worse when you get into the 1 to 3 Gigahertz microwave range.

Another problem with RG-59 is the connectors used are usually the old crimp style. These are often installed using the wrong tool so they are either loose or overly tight. Smashed, crushed or kinked cable results in a change of the cable's operating impedance and results in some signal being reflected back and forth in the cable. Of course, a loose connection causes trouble as well.

I would not suggest that you replace working coax. But if you have doubts about a particular run of cable, it's not worth fighting with. An amplifier should never be installed as a repair when there is real trouble still present elsewhere in the system. Before you go to a lot of work installing a new run of cable, 'ground lay' it... Run in on the floor, through a window or vent, etc. -- Just to verify that it really does improve the system performance. (If you prove the existing run of coax to be good, you may be left with one of the least expensive, but vital test tools, a known good cable.)