Stridsberg Multicoupler Alternative?

[Ubbe]

Does bias T flow through this

It can not. Antronix recommends their own $9 ARPI-2000 inserter with their VRA900B amp that has a 0,2dB attenuation.

The VRA900B has a 7dB noise figure. It means that if you can receive a -110dBm signal without the amplifier it will need to be 7dB stronger at -103dBm until you can hear it equally clear using the amplifier.

/Ubbe

 

[prcguy]

It can not. Antronix recommends their own $9 ARPI-2000 inserter with their VRA900B amp that has a 0,2dB attenuation.

The VRA900B has a 7dB noise figure. It means that if you can receive a -110dBm signal without the amplifier it will need to be 7dB stronger at -103dBm until you can hear it equally clear using the amplifier.

/Ubbe

I’m not a fan of using CATV amplifiers on antennas because they are not designed for it. A cable TV system is a closed system with a finite number of signals being roughly equal in amplitude when they reach a customers house and within an expected range of levels. There are no surprise signals that come and go at different levels as with an antenna and any amplifier used in a CATV system would be operating within a very predictable set of signals and levels. In this case noise figure is not much of a concern and the amplifier 1dB compression point and IP3 rating are not that great because they don’t have to be.

An amplifier inside a multicoupler for use with an antenna needs to have a reasonably low noise figure and a compression point and IP3 number high enough to survive in a very dynamic environment with very weak signals alongside very strong ones. Stridsberg seems to be a standard in the scanner community even though its amplifier specs are not very good. A CATV amplifier/splitter is usually going to have worse specs and worse performance when connected to an antenna.

 

[yellingsoftly]

I’m not a fan of using CATV amplifiers on antennas because they are not designed for it. A cable TV system is a closed system with a finite number of signals being roughly equal in amplitude when they reach a customers house and within an expected range of levels. There are no surprise signals that come and go at different levels as with an antenna and any amplifier used in a CATV system would be operating within a very predictable set of signals and levels. In this case noise figure is not much of a concern and the amplifier 1dB compression point and IP3 rating are not that great because they don’t have to be.

An amplifier inside a multicoupler for use with an antenna needs to have a reasonably low noise figure and a compression point and IP3 number high enough to survive in a very dynamic environment with very weak signals alongside very strong ones. Stridsberg seems to be a standard in the scanner community even though its amplifier specs are not very good. A CATV amplifier/splitter is usually going to have worse specs and worse performance when connected to an antenna.

Yah just wish there was a little better sourcing of multicouplers. I emailed Stridsberg with a question a couple days ago and no response so far. How to multicouplers like Stridsberg and Cross Country Wireless handle bias t input from an SDR? Do they require an antenna side bias t injector if you have your preamp/lna on the antenna side? I'm still on the fence on what I want to buy to add some more sdr's to my atc recording setup for academic purposes. Cross Country wireless appears to have one in stock right now with 5 ports, that might fit the bill pretty well honestly.

 

[Ubbe]

Do they require an antenna side bias t injector if you have your preamp/lna on the antenna side?

All multicouplers need a bias-t on its antenna side to be able to power an antenna amplifier.

It's usually a 50 ohm resistor at the in and output that will drain 100mA from a 5 v source, or it can be an impedance transformer that almost have a dead short for DC voltage.

If you get two of those ARPI-2000, or another cheap model, you can have one between multicoupler and SDR and any voltage from the SDR will come out of the bias-t power connector. You then take that voltage and feed into the second bias-t at the antenna side of the multicoupler. So you do not really need a separate power supply for the bias-t, although it might be cheaper than getting a second bias-t.

/Ubbe