Using TV amplifiers bad for scanners

[Flatshovel]

Good Evening,
I have a question that I could not find on the forum. I have a outside antenna that I would like to use along with a simple 3 way slitter to feed 3 scanners and use a TV Signal Amplifier to boost the signal from the antenna. By using this TV signal Amplifier would it be damaging to the scanner? By damaging I mean overloading the receiver to the point that it de-tunes the receiver and makes the radio deaf? I don't want to hurt my equipment but would like to boost the signals as it helps quite a bit, but don't want to hurt the receivers over the long run. Any comments on using these with outdoor antenna setups?

This is similar to the one I have: Radioshack - Products

 

[jackj]

Rest easy, there is no way that a properly operating TV signal amplifier could hurt your scanner. Some points that you should consider though:

1. Your scanner is designed with a 50 ohm antenna input which means that you would get optimum power transfer when using it with 50 ohm coax hooked up to an antenna that would supply a 50 ohm match to the feed line. TV amps are designed with a 75 ohm input and output.

2. Most of the newer TV amps only go up to around 500 MHz while you are going to be interested in signals that go up to 800 MHz.

3. While your scanner won't be damaged by being overloaded it might not work well. It is possible that a TV amp would overload your scanner if you live within 2 or 3 miles of a FM transmitter. Close cell towers will also cause a problem.

Your best bet would be to buy a distribution amp designed for communication receivers. It will have the right input and output impedance to match your scanners and feed line plus it will have enough gain to overcome the loss in your splitter.

 

[n5ims]

One other question you should ask yourself is where you should put that TV amp. Placing it near the antenna, you'll amplify the maximum signal and minimum noise. This will help to overcome the natural signal loss in your coax. Placing it anywhere else will cause you to amplify much more noise than signal since the signal to noise radio will have much less signal to the same (or even more) noise.

Good reception happens when the signal is significantly greater than that of the noise level. So doing what is necessary to increase signal is only worthwhile when doing so doesn't also increase your noise level by significant levels.

 

[737mech]

Electroline 8 port

I have and continue to use the EDA 8 port drop amp from Electroline. Only a +4db per port which evens off the splitting, and it has port isolation. Not too much amp for scanners, a regular tv amp of 20db would probably be too much. Then consider using an FM trap as well. EDA (Electroline) drop amps work as long as you don't pump a two or four port into your scanners. Way too much amp unless you are far away from your desired signals and towers. Try to keep the amp at +3.5/4.0 db.

 

[Flatshovel]

OK I have a question. How can you tell what the dB level is at the radio end. I am sure there is a calculation for it but I have no idea. I also have no idea what the amp is putting out either and what is being received at the antenna jack. So reading from the previous post a safe level at the receiver end would be 4 to 5 db, there is no mention of anything higher than this hurting or de-tuning things. Any suggestions? Comments or suggestions please.

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[krokus]

OK I have a question. How can you tell what the dB level is at the radio end. I am sure there is a calculation for it but I have no idea. I also have no idea what the amp is putting out either and what is being received at the antenna jack. So reading from the previous post a safe level at the receiver end would be 4 to 5 db, there is no mention of anything higher than this hurting or de-tuning things. Any suggestions? Comments or suggestions please.

Sent from my SM-G900R4 using Tapatalk

dB is a relative thing, used to indicate an increase or decrease in signal level. dBm is a reference, with 0 dBm being 1 mV. If a 0 dBm signal is amplified 10 dB, it is now a 10 mV signal. 20 dB would make it 100 mV.

Calculating the net gain or loss for a system is the end result of subtracting all cable, splitting, and insertion losses from any gains in the system. Then you can calculate how much of the signal entering the system is available at the output of the system.

Knowing how much signal is entering the system can be a whole different discussion.



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[K5MPH]

I have been using TV amp for years and they do work just make sure that it will cover the frequency range you want the the two im using go up to 950 Mhz some only cove up to 500 Mhz it will say on the amp what Frequency range it will cover,some Tv amps are 10 to 20 db gain the one's i am using are 10 db only......

 

[gmclam]

Regardless of the type of amp used (scanner, TV, etc), it is best to filter unwanted signals before they are amplified. I specifically filter AM and FM broadcast signals before my amps. ScannerMaster has a nice selection.

 

[Voyager]

It depends on what the RF environment is like in your area. If there are few or no strong transmitters, it can be added without much problem. If you have a lot of strong signals in your area, it could easily cause overload of the front end. No damage per se, but decreased performance.

 

[bep]

I have been using a Channel Vision CVT-15PIA amplifier. Covers from 54-1000MHz. I have an exceptionally long cable run. Without it I have zero bars. Using it with my ST2 it works great. I recently added a Yagi antenna to solve a multi-path issue. When I used the amplifier my signal was worse that without. Can't hurt to try.

 

[SCPD]

Outside

I have been using a Channel Vision CVT-15PIA amplifier. Covers from 54-1000MHz. I have an exceptionally long cable run. Without it I have zero bars. Using it with my ST2 it works great. I recently added a Yagi antenna to solve a multi-path issue. When I used the amplifier my signal was worse that without. Can't hurt to try.

Do you have this outside? I took a look at a pdf from the manufacturer, don't see where it says "don't put it outside". Thanks.