Can I use this duplexer to run a YAGI and VERTICAL to my scanner?

bobruzzo

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Duplexer
This is a Diamond duplexer and would this be fine for running 2 antennas to my 1 scanner? I have a YAGI and a small VERTICAL. The yagi is for one specific direction for a system I listen to and need the gain of a beam. The vertical is for my local P25 system.
 

nd5y

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It's only good if your two antennas and the systems you want to receive are on different bands and match the high pass/low pass frequency ranges the duplexer was designed for.
 

bobruzzo

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It's only good if your two antennas and the systems you want to receive are on different bands and match the high pass/low pass frequency ranges the duplexer was designed for.
Crap....ok guess I am outta luck. Both the yagi and vertical are 800 mhz! The problem is I cant receive the systems I have with just 1 antenna. I use the 800 mhz vertical to monitor the state P25 system, and I can receive all sites full scale. The yagi is so I can hear the Massachusetts state police system, but it's on the fringe edge of what the vertical can pick up. I mean I can hear the Mass state PD system on the vertical but it's scratchy. I want to use yagi to get a better signal in that direction. But if I use the yagi alone I wont be able to hear all the sites in the RI P25 system. Only other choice is to put each of those 2 systems on separate radios.
 

prcguy

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You would have to sweep that particular diplexer as its designed for 900MHz amateur. I have one and the 900 side works down in to the mid 800s ok but not to 800MHz even. It will vary slightly unit to unit. I believe they can be tweaked a little internally but that takes some test equipment.

The yagi is a dedicated 800 mhz and the vertical is also a dedicated 800 mhz.
 

prcguy

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Ok, how bout a remote antenna switch on the roof so you can easily switch between antennas and still use one feedline to the scanner? You would have to manually switch.

Crap....ok guess I am outta luck. Both the yagi and vertical are 800 mhz! The problem is I cant receive the systems I have with just 1 antenna. I use the 800 mhz vertical to monitor the state P25 system, and I can receive all sites full scale. The yagi is so I can hear the Massachusetts state police system, but it's on the fringe edge of what the vertical can pick up. I mean I can hear the Mass state PD system on the vertical but it's scratchy. I want to use yagi to get a better signal in that direction. But if I use the yagi alone I wont be able to hear all the sites in the RI P25 system. Only other choice is to put each of those 2 systems on separate radios.
 

bobruzzo

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Ok, how bout a remote antenna switch on the roof so you can easily switch between antennas and still use one feedline to the scanner? You would have to manually switch.
I thought of that too but I still want to be able to hear all 2 systems. Well I might get lucky and still be able to receive both systems with yagi.....yagi is supposed to arrive here later in week. I need to point it due east to pick up the Mass ST PD tower in Attleboro Mass. And hopefully I will still be able to receive the 4 RISCON sites as well. Three of those sites are in a north, and south direction. So maybe yagi will pick 'em up off side of it. It's a 6 element yagi so maybe beamwidth will allow it.
 

Ubbe

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It's so often you'll need several antennas to a scanner that scanner producers should think about having at least two antenna connectors and then choose which one to use by system, department or frequency, much like filter settings in SDS scanners. All band frequency filters in the scanner are connected to the single antenna jack by switching diods, why not add another set of switching diods and have another antenna jack? It shouldn't cost much to add that feature.

/Ubbe
 

bobruzzo

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It's so often you'll need several antennas to a scanner that scanner producers should think about having at least two antenna connectors and then choose which one to use by system, department or frequency, much like filter settings in SDS scanners. All band frequency filters in the scanner are connected to the single antenna jack by switching diods, why not add another set of switching diods and have another antenna jack? It shouldn't cost much to add that feature.

/Ubbe
Exactly, just like the dual and tri band ham radios....I used to have a Kenwood with a separate jack for UHF and VHF.
 
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