Looking for a tried and true Pre-Amp that I can feed thru a Bias-Tee,,I have used one from RF Bay and not really impressed by it,,Any ideas?
Pre-Amp
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ka3jjz
Wiki Admin Emeritus
Improve your antenna and feedline first before looking at a preamp...Mike
prcguy
Member
MiniCircuits has broad band models with better specs and cheaper prices than the broad band unit from ARR. Angle Linear made about the best single band preamps out there and one of the reasons they were in business so long was because of ARR and similar companies where people were fed up with mediocre performance and wanted something better.
My experience with RF Bay is that they are on a par with Mini-Circuits, which is to say excellent if you select the right preamp for the application. What preamp do you have that you're not happy with, and what is the application?
Bear in mind, a preamp can only go so far. If there's just no signal to work with being delivered by the antenna, no preamp will help.
Bear in mind, a preamp can only go so far. If there's just no signal to work with being delivered by the antenna, no preamp will help.
Ubbe
Member
If you can live without the metal box, or can get you own, I suggest getting pre-amp and bias-t from GPIO Labs.
GPIO Labs | eBay Stores
Ultra Low Noise Amplifier with ESD+ Gain Stabilization USB cable PGA-103 NF .5dB | eBay
The picture shows it can be powered from the coax but the schematic says it doesn't. But then you only do as the picture shows, put a choke coil between coax and the +5 volt. The device can also be powered with the built-in Bias Tee. For this, the 10 uH inductor (not included) needs to be installed. As well when using the Bias Tee, +5V needs to be applied on the RF output line to power the device. "
If you have the highest quality coax and antenna then a low-noise pre-amp only improve the signal quality slightly, the difference between the scanners internal noise and the pre-amps, maybe 3-4dB. The worse antenna and coax you have the more improvement you get with a pre-amp.
I tested by taking the antenna element of a magnet foot and only used the mounting screw as an extreamly short antenna and I could barely hear the transmission, but adding a GPIOLabs low-noise amplifier made the signal became fully readable. The more out of band mistuned antenna you have the more a pre-amp will help. Just what a scanner listener needs to get his antenna to work on all frequencies. Don't forget to add a variable attenuator to not overload the scanner and a FM trap filter might also be neccesary to use.
/Ubbe
GPIO Labs | eBay Stores
Ultra Low Noise Amplifier with ESD+ Gain Stabilization USB cable PGA-103 NF .5dB | eBay
The picture shows it can be powered from the coax but the schematic says it doesn't. But then you only do as the picture shows, put a choke coil between coax and the +5 volt. The device can also be powered with the built-in Bias Tee. For this, the 10 uH inductor (not included) needs to be installed. As well when using the Bias Tee, +5V needs to be applied on the RF output line to power the device. "
If you have the highest quality coax and antenna then a low-noise pre-amp only improve the signal quality slightly, the difference between the scanners internal noise and the pre-amps, maybe 3-4dB. The worse antenna and coax you have the more improvement you get with a pre-amp.
I tested by taking the antenna element of a magnet foot and only used the mounting screw as an extreamly short antenna and I could barely hear the transmission, but adding a GPIOLabs low-noise amplifier made the signal became fully readable. The more out of band mistuned antenna you have the more a pre-amp will help. Just what a scanner listener needs to get his antenna to work on all frequencies. Don't forget to add a variable attenuator to not overload the scanner and a FM trap filter might also be neccesary to use.
/Ubbe
prcguy
Member
You have to be careful recommending a preamp for broad band use. This specific preamp probably works ok for you because your in a very RF quite area. It would fail miserably at my location.
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