Cable TV amp for scanner use?

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Bob_61

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The cable guy(not Larry) left an amp. after replacing the cable to the apartment. Anyways it is a "multimedia drop amplifier 5-42/54-1002 mhz passive return" is it safe to use on a scanner? Thanks my knowledgeable friends for any info! ;)
 

burner50

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The problem with those amplifiers is that if you're trying to hear something, and the signal is weak, the amplifier may amplify the noise floor around what you're trying to pull in.

Amplifiers are best used when you have a strong signal and you want to send that signal through a long coax run. Not at the end of a long coax run.
 

Bob_61

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At this time I am using it to listen to a town 20 miles away which is on the other side of a hill called Avon Mtn. And it seems they using another repeater at this time of the year which is not on Avon Mtn. so it helps listening to them and the are using freqs. in 450-470 range. For that it is helping me out, I am not using it for local dept. So with that said, would it do any harm using it with a scanner? Which I don't think it would,but I could be wrong! :twisted:
 

gmclam

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Amplifiers

The answer to you question: it depends. I am using amplifiers, but the first thing I do is pass my antenna signal through a bandpass filter BEFORE the amplifier so that unwanted stuff is not amplified too. The strongest signals I don't want getting into my scanners are: AM/FM broadcast, TV broadcast and a couple of strong local paging signals. There's other stuff I don't want too, like cell phone towers, but they're mixed in the same bands as what I do want.

Some people think more is always better. One "problem" is that the scanner will typically adjust to the strongest signal. If the signal you want is weaker, and you pass them both through an amp, it won't fix that ratio. But if you're away from strong signals (out in the countryside) then an amp might help.

The reasons I use amps include overcoming cable loss on long runs and splitting signals to multiple receivers. But even for those applications I can't overload the amplifier inputs and still have to make sure unwanted signals are not the strongest. One more thing you might need to consider is the signal level out of a cable TV amplifier, and that it is not "too much" for a scanner front end.
 

kayleesdad

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Just for fun I attached the discone to the TV 75 ohm cheapie preamp and 75 ohm fm trap and the TV digital reception was much better than the so called cheapie digital antennas. Then attaching the preamp and filter to a couple of different scanners increased reception okay too. May get a decent 50 ohm preamp and 50 ohm filter for the scanners, but probably will get a Yagi first. The unidens don't over load as easily and the gre's seemed to benefit from the fm trap when attached to a discone. Maybe get some decent coax too if money permits.
 

Bob_61

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Just for fun I attached the discone to the TV 75 ohm cheapie preamp and 75 ohm fm trap and the TV digital reception was much better than the so called cheapie digital antennas. Then attaching the preamp and filter to a couple of different scanners increased reception okay too. May get a decent 50 ohm preamp and 50 ohm filter for the scanners, but probably will get a Yagi first. The unidens don't over load as easily and the gre's seemed to benefit from the fm trap when attached to a discone. Maybe get some decent coax too if money permits.
Well this little amp works for me with no trap! The cable guy said keep it, so I did....
 

Thayne

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Also for receiving don't worry about the impedance mismatch too much, high quality 75 ohm coax is much cheaper than low loss 50 ohm for receiving.
 

JLShafar

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About a year ago I wired my old cable TV video filter inline to my scanner coax as an experiment, and it resulted in much stronger, clearer, and quieter (less hiss) signals on all of my VHF and UHF freq. I had to replace the BNC ends with RG6 ends to adapt to the terminals on the amplifier. I started picking up signals over 100 miles away that I really didn't want to hear, so I wired a switch to it to easily turn it on or off from my desk as needed. My antenna is a 16-element discone which I am really happy with. Wal-mart still sells the exact same amps in the cable TV accessories department. Specs are as follows: 120 VAC, Video amplifier., single output, VHF/FM/UHF, 12 dB, 50-900 Mhz. For $20.00 it is hard to beat. Maybe it isn't supposed to work ...but it does!
 
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kb0nly

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I use a PCT drop amp to feed my two scanners at once, works great. If you go this route just don't get one with an amplified return for cable internet. I tried one of those cause it was cheap, problem is it would take noise from the scanners and amplify it to the antenna.
 

n5ims

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does this really work for a digital scanner
Like gmclam said in his post, "it depends". With the some conditions it could make things better and other conditions it could make things worse (it could also make no difference at all). There is no magic trick here and what works great for one person may be the worst solution for another person.

An generic amp will increase the level of everything (good & bad) and the lower the quality of that amp, the more bad things it can add (distortion of the waveform for one common example). If you have some very strong signals around that are overloading your scanner an amp will make this worse (probably much worse).

A high quality amp designed specifically for scanner (or commercial two-way receiver use) will be designed to take low level signals and amplify them with minimal distortion with limited additional noise level being added. A cheap cable-tv amp (which is made for a strong signal to start with and designed to overcome the loss from long cable runs) will amplify not only the signal, but also the noise and generally distort the signal to some degree.

The nice thing about the cheap cable-tv amps is that they're really cheap so you may want to try one out to see if it helps or hurts. If it helps, fine it works for you. If not, you know that's not the solution and you didn't spend too much on a solution that didn't work out.
 

ecollins11

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I use this setup for using multi antennas with my pro 163 an pro 197 I have a Driectv splitter with a high isolation between the ports I have a 800 mhz omni an a Vhf/Uhf omni antennas connected to the Directv splitter through a RS FM Trap an into a RF Communcations 8db Catv drop amp an using 2 of the outputs to each scanner and it works great The Driectv splitter is 2 -2150 MHZ an the Catv drop amp is 54-1000 Mhz 8db an 5-42 Mhz pass through. The only cost I have in the setup is the FM Trap I found the AMP an the Driecv splitter in CableOne's Dumpster an found 2 more of those amps and single port 15db amp.
 

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