Anyone tried using a cable tv splitter/ amplifier for feeding more than 1 radio from an anntenna? any good? sd
catv amplifier/splitter for scanning
- Thread starter KD8CES
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Search the site for channelmaster dropamp. You should find lots of posts with the info you are looking for.
Splitters yes .. amplifiers no
Yes. I am using some good quality "TV" splitters (5-1000MHz) to drive multiple scanners. Amplifiers are another issue though. I actually installed a couple of filters from my outdoor antenna (long before the splitter) to reduce strong signal interference. An amplifier would have only made that worse.scannerdweeb said:
There is a parameter of amplifiers and mixers (an therefore receivers as a whole) called "noise figure". In order to actually improve the ability to receive weak signals, the amplifier you add MUST have a noise figure that's lower than the receiver that follows it.
According to measurements I have made, many scanners have noise figures in the range of 4 to 6 db. I've measured cable tv drop amps with noise figures as high as 8 db. Putting an 8 db amp on a 4 db receiver would be quite detrimental, in spite of the fact that strong signals would appear stronger. And that doesn't even begin to address the possibility of overloading the receiver.
Not all cable amps are that bad, and not all scanners are that good, so your mileage may vary. Try it, and don't be surprised when it doesn't work. Be surprised if it does.
According to measurements I have made, many scanners have noise figures in the range of 4 to 6 db. I've measured cable tv drop amps with noise figures as high as 8 db. Putting an 8 db amp on a 4 db receiver would be quite detrimental, in spite of the fact that strong signals would appear stronger. And that doesn't even begin to address the possibility of overloading the receiver.
Not all cable amps are that bad, and not all scanners are that good, so your mileage may vary. Try it, and don't be surprised when it doesn't work. Be surprised if it does.
k8mcn
Member
a Good quality splitter will work well for splitting the signal between two scanners, IF you have a good signal to split---and remember this is for receive only--don't try it with a transmitter IE-2 meter rig etc.scannerdweeb said:
As for amplifying the signal, thats a different beast,and one i am not at all knowledgeable in.
CE TECH 4-Way Distribution Amplifier-23550 - The Home Depot
I have something similar to that attached to my 2 scanners, it works pretty good, but is it safe?
I have something similar to that attached to my 2 scanners, it works pretty good, but is it safe?
If the amp only boosts 4.5 db no worries for scanners. I use the Electroline drop amp 8 way splitter. It feeds eight scanners. The boost is only 4 db and that makes up for the splitting. There is a youtube video on the whole concept for coax and drop amps and how to figure out the loss numbers and when to use an amp. The video is for tv signals but the information is the same for scanner antenna setups. https://www.youtube.com/watch?v=3wvAzjKxE_E One additional thing to look for is port isolation. I don't think that cheap two way has any port isolation. What happens is one scanner will hit on a freq while a signal is picked up and actually reflect it backwards down the coax, then the other scanner hits on the same freq and you are listening to the same thing on every scanner. Port isolation stops that so each scanner can do it's own thing.
A few months ago I bought an old Radio Shack TV splitter / amp at a Goodwill store for $3. I brought it home and plugged it in to see if would pass the "smoke test" and it did, seems to work ok. I haven't tried actually hooking it up to a scanner yet, though.
Eng3ineer
Member
Yes, I use three Electroline drop amps... Two are the single port (Think 2100 model) mounted at the antenna with single run of RG6U that feeds a 4 port splitter. One feeds my railroad feeds the other is used for ATCS. The third is a four port Electroline amp (2400 model) also mounted at antenna with four runs of RG6U to four scanners that are my FD and PD feeds
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