Amplifier?

[Netdragon]

I have a UBCD536PT scanner running off a discone antenna, signal inside is fairly decent (i am rural) however if I want to use it in a different spot, I need to use the extension as the cable coming in is not long enough. This greatly weakens the signal so was wondering if a signal amplifier will work and which one to buy. I have two scanners so maybe a splitter with amplification might be the go..however the second scanner is more for portable use so that is not a priority, getting a good signal on the 536 is my main objective right now.

Any direction on this would be great. Am not an an expert in these matters by a long shot.

 

[Ubbe]

You have the discone indoors now and want it outdoors. It's important to get an antenna as high above ground as possible if monitoring weak signals. The less obstruction of the RF signals the better and free line of sight to the object you monitor are the best.

You can use a new RG6 coax the whole way, they are well shielded and have low loss. Any amplifier based on PGA103+ works great and then add a bias-T to feed power to it from the coax.

If you search for emc preamplifier on Amazon Ebay AliExpress you'll find blue boxes that use PGA103+ and those need 12v from an external source. You then buy two bias-t and have one at the scanner end of the coax and the other between amplifier and coax and connect its 12v input to the amplifiers 12v. At both ends the bias-t RF+DC end goes to the coax and the capacitor RF end to scanner and amplifier.

Buy one 3dB and one 6dB attenuator and if the scanner overloads you can first try the 3dB one and then the 6dB and finally both together. You can also buy a variable type that goes between 0-20dB and adjust until all overload issues are gone, if you experience any at your rural location.

You can split the 12v power to your scanner to drive a bias-t. One female to two male and you cut off one male and use the center wire connected to the bias-t. Ground comes from the scanners antenna connector so isn't really needed if the bias-t doesn't have any screw or solder lug for ground.

For splitter to several receivers you can use any CATV splitter and buy cables with F connector at one end and BNC or SMA at the other.

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/Ubbe

 

[Netdragon]

ok, a bit more complicated than what I thought. First, thanks for responding and being indepth but it might take me a few reads to understand.

I have the antenna up on the roof outside already..with a cable coming inside just through the window. Scanner receives fine when I hook it straight into the cable next to the window where it comes inside. However, the cable is not long enough to reach any further and if I use the extension cable to place my scanner at a different location (like my desk), the transmissions start cutting out at the start and are patchy. Move it back, and it's fine. I am not electrically minded and a lot of what you said went over my head. I was hoping there was a simple "plug the outside cable in one end and the extension cable into the other end" solution.

Please dont laugh at my naivity, I am only learning, not electrical minded, and am not a fit person, Any changes to the antenna and cable that is already attached to the roof means employing someone, as I cannot do this myself. Am just looking for an easy uncomplicated solution if there is one.

Thanks again

 

[cavmedic]

ok, a bit more complicated than what I thought. First, thanks for responding and being indepth but it might take me a few reads to understand.

I have the antenna up on the roof outside already..with a cable coming inside just through the window. Scanner receives fine when I hook it straight into the cable next to the window where it comes inside. However, the cable is not long enough to reach any further and if I use the extension cable to place my scanner at a different location (like my desk), the transmissions start cutting out at the start and are patchy. Move it back, and it's fine. I am not electrically minded and a lot of what you said went over my head. I was hoping there was a simple "plug the outside cable in one end and the extension cable into the other end" solution.

Please dont laugh at my naivity, I am only learning, not electrical minded, and am not a fit person, Any changes to the antenna and cable that is already attached to the roof means employing someone, as I cannot do this myself. Am just looking for an easy uncomplicated solution if there is one.

Thanks again

How long is the extension cable you are using and how is it being coupled. You could have a bad patch cable, bad connectors on it , bad couple or all of the above.

 

[Netdragon]

How long is the extension cable you are using and how is it being coupled. You could have a bad patch cable, bad connectors on it , bad couple or all of the above.

It's about 13 metres (42ft). Cable from antenna 10 metres (32ft ) before extension. So extension is about 3 metres (9ft)

I managed to get a recommendation via a friend, and I am off to buy that on Monday. Its just a 2 way indoor distribution amplifier and some accessories to connect. It should solve the issue, as he is using it in same manner. If not, will look into the cabling but I had it all installed by a professional radio antenna guy (cost me an arm and a leg). I had purchased the antenna separately and it came with a ten metre cable (being used as the outdoor cable). That cable might be sub par but I cant check that now. The second cable (extension) is RG58 However as mentioned, the signal coming in via the outdoor cable is fine, its only when I attach the extension. I will test all that out and see how I go from there.

For the record, I have another scanner which I have placed outside. That is picking up the full transmissions..but when the 536 is attached to the extension, I miss the first few seconds of the transmissions, and some dont come through at all, if it is not a long transmission.

Thanks everyone for the replies.

​

 

[Ubbe]

the signal coming in via the outdoor cable is fine, its only when I attach the extension. I will test all that out and see how I go from there.

That short 9ft extension of RG58 should be no problem so it must be some kind of issue with that extension cable.
You only need that distribution amplifier if you plan to use several receivers.

As the signal coming from the outdoor cable are fine you do not need anything more than a fully working extension cable.
It's usually the connectors or adapters that are the problem. Wiggle the connectors while listening to a weak signal to check if it is a bad connector.

/Ubbe

 

[Netdragon]

That short 9ft extension of RG58 should be no problem so it must be some kind of issue with that extension cable.
You only need that distribution amplifier if you plan to use several receivers.

As the signal coming from the outdoor cable are fine you do not need anything more than a fully working extension cable.
It's usually the connectors or adapters that are the problem. Wiggle the connectors while listening to a weak signal to check if it is a bad connector.

/Ubbe

Thanks.

A bit of an update. I got the amplifier and a new cable. Working well. I will be running a second scanner soon so the distribution amplifier will come in handy. Thanks again.