if amp would help or hurt

[tntnt44]

Hi all thanks for the great posts , I have a db4e and just combined a c5 to get my channel 10 and pbs channels , it is working well the best numbers of strength i get are 72 percent on my abc , nbc and cbs I have aimed at 324 and its not my best I am about the 300 area to get my best numbers , they are on same pole db4e on top and 3 feet in between i am thinking the combinine of 2 antennas has brought my numbers down had about 100 percent on the majors on uhf pbs is about 80 percent and works fine channel 10 is 72 and is working fine would a amp help or hurt? thanks for your help have a good holiday all! Gil

http://www.tvfool.com/?option=com_wr...8e03a195cea8af

[rabbit73]

Welcome to the forum, tntnt44:

it is working well the best numbers of strength i get are 72 percent on my abc , nbc and cbs

With digital signals it's pretty much you get it or you don't. The signal strength numbers are relative. What we don't know is how close they are to the "Digital Cliff" where you get pixilation, picture freeze, and finally dropout. You can see how much margin you have before disaster by inserting an attenuator in the coax to find out what the lowest numbers are before you have problems.



If you have a lot of margin before disaster, you don't need a preamp. If you are close to the digital cliff, a preamp would help.

You can use several splitters in series as an attenuator. A 2-way splitter has a 3.5 dB loss. A 4-way is 7 dB loss. Or, you can buy some inexpensive attenuators, one variable, and some fixed.
https://www.antennasdirect.com/store...ttenuator.html
http://mjsales.net/collections/atten...ant=1083705673
•Attenuation values 1, 3, 6, 8, 10, 12, 16, 20dB (FAM)
click on 1 dB for other values; the up and down arrows are faint

http://www.3starinc.com/drop_in-line_attenuator.html
http://home-automation.smarthome.com...=&w=attenuator

Where are your antennas located?

Are there any trees in the signal path?

I have aimed at 324 and its not my best I am about the 300 area to get my best numbers

Should be 311 degrees magnetic by a real compass.

I see a possible problem; you have some strong local FM signals that might interfere with TV reception, especially with the C5 VHF-High signals 10 and 9 for ABC and PBS. You need an FM filter. See attachment 2.

[tntnt44]

Thanks Rabbit for getting back to me , I have both antennas on roof uhf is about 24 feet and vhf 3 foot under we do have some trees about 3 med size homes away so i have tried aiming in gaps there is not much change in the 300-320 range on compass with 1 exception on fox 40.1 at the 300 range it is 85 percent my 58.1 is a channel we like and it is up and down 50-60 percent , so which FM trap or item to you recommend to try ? I am feeding 3 TVs thanks again for your help Gil

[rabbit73]

The FM filters to consider:
http://www.mcmelectronics.com/produc...-FM-88-/33-341
https://www.antennasdirect.com/store...on_filter.html
http://comingsoon.radioshack.com/rad...l#.VZmnhTjbJLMvery slow link

Preamps to consider:

Antennas Direct Juice, Channel Master 7778, RCA TVPRAMP1R

The Juice has a good Noise Figure, is resistant to overload, does not have an FM filter so you should add one between the antenna and the input of the preamp, does have a 4G-LTE filter which is becoming more important because of interference from new mobile phone frequencies just above UHF TV channels

The 7778 does has an FM filter

The RCA performs well, is inexpensive, has a reputation for poor quality control, the separate/combined switch sometimes doesn't make good contact with the VHF input in the separate position, the workaround is to use the combined position and an external UVSJ UHF/VHF diplexer like the one that comes with the C5

[tntnt44]

ok have the 1500024 on the way ,thanks again will try and test the cliff this week Gil