Signal strength questions

[menelfloss]

I searched and searched for this answer thinking it must have been asked many times. But here goes anyway.
I put a splitter on my antenna line to go 1. to my 722, (displays OTA in yellow and displays programming info after phone update) and 2 direct to my TV.
This has decreased the signal strength from 90 to mid 80's. Every thing looks ok.

Some stations come in at mid 70's.

My question is, with digital it is there or not there. Do I want higher signal strength no matter what? Is it worth me experimenting with an amp, or better antenna? Do I skip the splitter and just hope that when the dish goes out due to weather my OTA signal passes through?

Thanks,
Mike

 

[ciwsguy]

A splitter will reduce your signal strength by 3.5 dB (a little over 1/2). It may work like this, but if the signal strength is reduced too much, you'll end up with a pixelized (or choppy) picture, or no picture. If you have a doubt, use an adjustable amplifier feeding the splitter, or install a distribution amplifier in place of the splitter.

 

[menelfloss]

Ahhh Ha!
I have a distribution splitter in the basement also. That splitter feeds 4 lines to the house from the antenna. Perhaps an amplified splitter there first....
Thoughts?

Mike

 

[ciwsguy]

Ahhh Ha!
I have a distribution splitter in the basement also. That splitter feeds 4 lines to the house from the antenna. Perhaps an amplified splitter there first....
Thoughts?

Mike

You're losing way too much signal strength. A 4-way and a 2-way will kill your signal strength. Recommend you replace your "distribution splitter" with a distribution amplifier.

 

[menelfloss]

Alrighty then,
I will give that a shot and report back.
Thanks,
Mike

 

[Jim5506]

The 4 way looses you about 7dB the two way 3.5dB. If you put a 2 way after a 4 way you have 1/16th of the signal or less. Better than a distribution amp, put a pre-amp at the antenna so the signal is amplified at it's purest point possible.

 

[menelfloss]

How far up stream should the pre-amp be?
I suspect it requires power... (trying to figure how to get power up there....
Mike

 

[Jim5506]

Pre-amp is mounted as close to the antenna as possible, some are included at the antenna.

Pre-amps require a power injector located directly down stream of the pre-amp (no splitters, etc).

 

[Pepito]

Loose Signal When Using Splitter

Can you explain how the Splitter can reduce the DB on your Antenna signal?

 

[ciwsguy]

Can you explain how the Splitter can reduce the DB on your Antenna signal?

Well, in layman terms, your coax cable is a transmission line. If you look at a transmission line as being a water pipe of a given diameter and a given water pressure available, open the valve and measure how much water flow comes out. That's akin to your signal stength into one TV. If you divide that single spigot flow into two spigots via a Y adapter you will find that a little less than 1/2 of the single spigot flow comes out of each Y-spigot. You will have some pressure loss in the Y-adapter, which is why you have a little less than 1/2 water flow. Adding more Y-adapters down stream of the splitter will eventually result in very low pressure and a trickle of water flow out of the spigots.

In electronic jargon, 3 dB of loss is a loss of half the power input to the splitter. 3.5 dB loss is a little over 1/2 loss because no splitter provides a perfect impedance match as some signal input to the splitter reflects back to the antenna, and some is lost to resistance. Does that help?

 

[menelfloss]

I bought a Channel Master CM 3044 1 to 4 distribution amp on line from Solid Signal for 27.99, 33.94 with shipping. I noticed some vendors were selling them up to around 50 bucks.

I installed it and found my signal strength to go up about 20 points (using the signal meter of the 722 DVR and also of my Sony Bravia's). My distribution point is in the basement about 30 feet from the antenna. I know this amp should be closest to the source, but I am not climbing around into my crawl space rafters where the antenna is now that it is 12 degrees below zero.

I am using three of the four outputs and tested to see if a cap over the non used one made any difference. The cap is a store bought do hickey that has a insulated pin in the middle and screw on cap. It is supposed to stop leakage of signal. It had no effect on or off of the unused output.

One more thing. Some of my readings might be skewed because it is so cold out this weekend. -15 last night and now -12. Signal strength is always the best at the cold temps.

None the less, the one station which I was not able to lock on to and that would stutter if I was able to lock during cold weather is coming in fine now. Other stations are all in the upper 80's to 99%.

Thanks for the help and suggestions,
Mike

 

[ciwsguy]

I am using three of the four outputs and tested to see if a cap over the non used one made any difference. The cap is a store bought do hickey that has a insulated pin in the middle and screw on cap. It is supposed to stop leakage of signal. It had no effect on or off of the unused output.

Mike,
Those cap do-hickeys are actually 75 ohm termination loads. I see the same results - i.e., no visible difference with it or without it. Just to close the unused RF circuits, it is best to terminate them to remove any hint of unwanted signals encroaching into your system. Glad your up & running now.

 

[menelfloss]

Ahhh Ha!
Termination loads eh? In my best Austin Powers voice... "I knew thah... I knew it, really eye did" (not)
I decided to keep the unused one caped. Thanks for giving me the reason why I even have these little things.
I'm hoping I will keep good signal once it returns to warmer weather, like 25 degrees above zero.. That is where I began seeing signal degridation the first time.

Mike

 

[menelfloss]

Well,
Now that it has gotten quite a bit warmer, close to freezing, the signal strength is still fine.
Problem solved.
Thanks for the help and suggestions,
Mike