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JCortez
24-Sep-2012, 11:53 AM
I recently installed a CM2020 antenna outdoors at 16 ft. and a 7777 preamp. Split to three TVs. I am 35 miles from transmitters at anywhere from 45 degrees to 51 degrees by compass. I cannot receive NBC (WFLA) nor can I receive FOX (WTVT) good enough to prevent pixelation and dropout on all three TVs.
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d2df93130823e04

signals unlimited
24-Sep-2012, 12:21 PM
I would remove the 7777 amplifier. Chances are the gain is too much for the strong signals in your area. Try bypassing both the amplifier and power supply to see if your reception improves.

No pre-amplifier should be needed, but you could use a Channel Master 3413 distribution amplifier to feed your three sets.

JCortez
24-Sep-2012, 1:18 PM
Thanks. I had the preamp on one TV only and got no signal because of the excessive gain, then I split the signal to three TVs. If channel 8 is not coming in now and 13 is weak, will removing the preamp and going to a distribution amplifier bring in these channels? The other channels come in fine.

No static at all
24-Sep-2012, 1:20 PM
In addition to Signals Unlimiteds suggestions I have a few questions;

Is the antenna close to any metal like a chimney cap?
Is the FM trap engaged on the 7777 preamp?
Are you receiving PBS (WEDU-3.1)?
Have you tried connecting the antenna directly to just 1 TV with no amplifier or splits?

JCortez
24-Sep-2012, 1:42 PM
I had the antenna hooked up to one TV without the preamp, but did not think the reception was very good. That is why I got the preamp. I will have to revisit removing the preamp and start this process of elimination again. I am learning as I go. WEDU 3.1 is very weak with the preamp and splitter. No metal in vicinity, besides the mast.

No static at all
24-Sep-2012, 1:49 PM
How about the FM trap? Do you know if it is engaged? All of your problem channels are VHF & you've got a strong FM signal in town, so it may make a difference.

signals unlimited
24-Sep-2012, 3:05 PM
Yes, FM is most likley your remaining issue. I think that with the 7777 in your trap was on but you were overloading. With the 7777 out, overloading was out and FM in.

With the 7777 out and the 3413 in, add a FM trap at the antenna.

This should restore all of your channels.

teleview
24-Sep-2012, 5:13 PM
Is the antenna mounted above the roof in such a manner that the roof is not restricting or blocking reception??

As always , trees and tree leaves do a real fine job of , reducing , reflecting , blocking , Tv reception and so do buildings and other obstructions.

It is best to install the CM2020 at a location that has least amount or no amount of obstructions of any type or kind of the directions of reception.

At your location that is , north , north east , south east.

Aim the CM2020 at about 85 degree magnetic compass direction.

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

The Tv transmissions a Very Strong at your location.

The following is Test of reception.

Remove ALL parts of the preamplifier , the outside preamp , the inside power supply and power injector.

Install a New matching transformer (balun) to the antenna.

Connect New a Coax to the matching transformer and run the New Coax through a open door or window , ->direct to the Tv<- , no splitters , no couplers , no nothing.

Antenna -> matching transformer -> coax -> Tv.

Scan for the digital broadcast Tv stations channels.

What is reception like Now??

JCortez
24-Sep-2012, 8:22 PM
I have removed the preamp and attached the antenna to just one TV and do not get 8 or 13 and 10 is iffy. The preamp was new and was left in the factory setting, so I assume the FM trap was "IN". If I switch that to "OUT", would that make a difference? One other note that I did not mention: all the TVs are probably at least 50 ft. from the antenna. There are two splitters--one on the incoming signal going to one TV and to another splitter which takes care of the other two TVs. I also cannot find a 3413 model distribution amp. They go from 3412 to 3414.

No static at all
25-Sep-2012, 12:14 AM
The "IN" setting of the FM trap is correct.

Have you ever tried moving the antenna to a different location? VHF is more prone to multipath (signal reflections) than UHF. An amplifier won't help that much if the signal quality is poor to begin with.

JCortez
25-Sep-2012, 12:58 AM
The antenna is rather permanent where it is. The mast is on a wood block on a concrete slab at grade and attached to a partition wall built for this purpose. Both grounds are attached. I could possibly raise it a few feet, and probably will, but not relocate. It is where the cable comes in from Brighthouse and is distributed. I think I will canvas the neighborhood looking for antennas and see what others might be doing. This is certainly more trouble than I anticipated. I appreciate all the help I am getting and the time you folks have spent on my problem. I hope I can report some success shortly.

Thanks

signals unlimited
25-Sep-2012, 11:57 AM
I have seen FM so strong that it got by the trap in the amp. Try a trap and the lower gain amplifier with a built in trap.

JCortez
26-Sep-2012, 1:04 AM
Yes, that is what I will try; an FM trap and a lower gain amplifier with trap. Do you have a favorite FM trap?

Thanks.

No static at all
26-Sep-2012, 2:19 AM
I'm thinking it's more of a signal quality issue at this point. The VHF section of the Channel Master antenna is just not that good when it comes to rejecting multipath. The specs (http://support.channelmaster.com/attachments/token/tk870ics5baqf50/?name=CM20xx+Series+Data+Sheet.pdf) indicate a rather wide VHF beam width which is not good unless a clean, reflection free signal is seen at the antenna. There is no reason why you shouldn't be getting the desired VHF channels with one set connected directly to a proper antenna.

If I were in your shoes, I would also consider the Antennacraft HBU 33 from Radio Shack as a possible solution. If it doesn't help, you can always return it for a full refund.

signals unlimited
26-Sep-2012, 1:09 PM
I use a CZFM-88. Not sure of the manufacture. If you want, I can ship you one to try. Just contact me thru my site. www.tripleplayantenna.com.

teleview
26-Sep-2012, 6:47 PM
Turn the antenna more toward 48 degree magnetic compass direction.