2018-08-07 22:28:55 +02:00
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Satnogs Diplexer
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A 2m/70cm diplexer intended for use in [Satnogs](https://satnogs.org/) ground stations.
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It is loosely based on the [micro-diplexer by kw4fb](http://kw4fb.com/micro-diplexer/).
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In addition to the high pass filter for 70cm and the low pass filter for 2m,
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this design also included an additional high pass filter at 120MHz,
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to eliminate interference by strong FM radio broadcast stations.
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Each antenna input provides an optional bias-tee to power a the antenna's LNA.
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See the [schematic](pcb/plot/diplexer.pdf) for details.
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The layout file files can be found in the `pcb` folder.
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`qucs` contains a [QUCS](http://qucs.sourceforge.net/) simulation for the diplexer.
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The files are provided under the CERN Open Hardware Licence v1.2.
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Filter Design
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-------------
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2018-12-28 12:18:43 +01:00
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![QUCS schematic](http://gogs.zenerdio.de/sebastian/satnogs-diplexer/raw/master/qucs/filter_sim.png)
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2018-08-07 22:28:55 +02:00
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**Full band S-parameters**
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2018-12-28 12:18:43 +01:00
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![Full band S-parameters](http://gogs.zenerdio.de/sebastian/satnogs-diplexer/raw/master/qucs/full_band.png)
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2018-08-07 22:28:55 +02:00
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**2m band attenuation**
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2018-12-28 12:18:43 +01:00
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![2m band attenuation](http://gogs.zenerdio.de/sebastian/satnogs-diplexer/raw/master/qucs/filter_2m.png)
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2018-08-07 22:28:55 +02:00
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**70cm band attenuation**
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2018-12-28 12:18:43 +01:00
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![70cm band attenuation](http://gogs.zenerdio.de/sebastian/satnogs-diplexer/raw/master/qucs/filter_70cm.png)
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2018-08-07 22:28:55 +02:00
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Circuit Boards
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--------------
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2018-12-28 12:18:43 +01:00
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![PCB top](http://gogs.zenerdio.de/sebastian/satnogs-diplexer/raw/master/pcb/plot/top.png)
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2018-08-07 22:28:55 +02:00
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2018-12-28 12:18:43 +01:00
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![PCB bottom](http://gogs.zenerdio.de/sebastian/satnogs-diplexer/raw/master/pcb/plot/bottom.png)
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