Backup Avionics

I will most likely be installing a Kanardia Horis + MAGU remote magnetometer. The Horis has a GPS input, and I want this to benefit from the roof top GPS antenna (Rami 801) which I have previously installed, sharing with the Flarm fusion. There is the question of which unit actually powers the GPS antenna, which contains a front-end which is DC powered from the RF connection.

The Rami 801 requires at least 4.5V

The Flarm Fusion puts 4.5V onto its GPS SMC connector

The Horis puts 3.3V onto its GPS SMA connector

The GPS must be therefore powered from the Flarm Fusion, as the Horis does not appear to put out enough voltage

An RF splitter is needed that blocks DC on one output port (which is connected to the Horis) and passes DC on the other output port (which is connected to the Flarm fusion). This splitter applies a DC load (270ohms to ground) on the DC-blocked port so that the connected device (the Horis) does not think an antenna is not connected (an error state which might be implemented)

A suitable splitter is the Rojone AMA-2251-1400-2MSDCB:

https://www.rojone.com.au/wp-content/uploads/2014/11/AMA-2251-1400-SERIES-GPS-2-4-WAY-DIVIDERS-CODE-AMA-2251-1400-2MSDCB-AMA-2251-1400-4MS-ROJONE.pdf

Also,

I will need to purchase three additional SMA male connectors

132195 AMPHENOL RF, RF / Coaxial Connector, SMA Coaxial, Straight Plug | element14 Australia

but I have enough spare RG400 cable