Multicoupler and fm trap

[Bonkk083]

If I add a fm trap filter will the multicoupler make up the loss

 

[mmckenna]

Does your multicoupler include an amplifier, or is it passive?

 

[Bonkk083]

Does your multicoupler include an amplifier, or is it passive?

Amplifier

 

[dlwtrunked]

If I add a fm trap filter will the multicoupler make up the loss

The loss of a good FM trap should be near negligible outside a certain intended range. Gain in a multicoupler counters to some extent the FM trap. You cannot really consider one without the other and the specifications of each. But in my experience, a GOOD FM trap (like the Mini-circuits and yes, good is not cheap) first is what one should start with and go from there. In general, you will not go wrong doing that.

 

[Ubbe]

FM traps should only have some 1-2dB loss outside of the broadcast band and a Stridsberg have a 3dB gain or more. But a Stidsberg isn't really a low noise device, having something like a 3dB noise figure and are bit too sensitive to loose sensitivity when exposed to high signal levels. If you lowest reception in a receiver are -120dBm then a Stridsberg will change that to -117dBm and a filters 2dB connected before the Stridsberg will change that to -115dBm.

A better solution would be an antenna amplifier with less than 1dB noise figure that will compensate for all devices noise figures, even a receivers relative high noise figure as scanners always have bandpass filters before any amplification that could have some 3-4dB loss. It would then change that -120dBm value to lower than a -122dBm sensitivity and you then can use a passive splitter instead of a expensive multicoupler. (-122dBm=0.18uV -120dBm=0.22uV -115dBm=0.4uV)

/Ubbe

 

[Bonkk083]

FM traps should only have some 1-2dB loss outside of the broadcast band and a Stridsberg have a 3dB gain or more. But a Stidsberg isn't really a low noise device, having something like a 3dB noise figure and are bit too sensitive to loose sensitivity when exposed to high signal levels. If you lowest reception in a receiver are -120dBm then a Stridsberg will change that to -117dBm and a filters 2dB connected before the Stridsberg will change that to -115dBm.

A better solution would be an antenna amplifier with less than 1dB noise figure that will compensate for all devices noise figures, even a receivers relative high noise figure as scanners always have bandpass filters before any amplification that could have some 3-4dB loss. It would then change that -120dBm value to lower than a -122dBm sensitivity and you then can use a passive splitter instead of a expensive multicoupler. (-122dBm=0.18uV -120dBm=0.22uV -115dBm=0.4uV)

/Ubbe

Will it be better without the Stridesburg that has more noise for weak signals I noticed more static

 

[Ubbe]

Will it be better without the Stridesburg that has more noise for weak signals I noticed more static

If you only use one of its outputs then reception will be better without the Stridsberg. You use it to compensate for splitter loss when you have 2 or more receivers connected to the same antenna.

/Ubbe