Garmin GTN 750Xi synchro heading from Collins PN101 HSI

[turbosuper]

I am trying to get synchro XYZ heading input working from a Collins PN101 HSI to a Garmin GTN 750Xi. I want this so I can have "heading up" orientation on the XM weather map page of the GTN. Does the Collins PN101 331A-3G p/n 522-2638-006 have 26VAC across pins V and W? The old GTN 750 install manual has an interconnect for a Bendix/King KI-525A HSI and that HSI requires an inverter such as a MD26-28 to be spliced in for HDG XMT H & C. Does the PN101 also need an inverter or does it have one built in? I measured the voltage across pins 15 and 36 on the GTN J1005 connector and there is no voltage. Pin 15 goes to PN101 pin W bootstrap XMT C. Pin 36 goes to PN101 pin V bootstrap XMT H. I have attached an interconnect for how I have it wired, the Garmin interconnect for the Bendix/King HSI, and the Collins wiring diagram.

 

[Jon Wilder]

I am trying to get synchro XYZ heading input working from a Collins PN101 HSI to a Garmin GTN 750Xi. I want this so I can have "heading up" orientation on the XM weather map page of the GTN. Does the Collins PN101 331A-3G p/n 522-2638-006 have 26VAC across pins V and W? The old GTN 750 install manual has an interconnect for a Bendix/King KI-525A HSI and that HSI requires an inverter such as a MD26-28 to be spliced in for HDG XMT H & C. Does the PN101 also need an inverter or does it have one built in? I measured the voltage across pins 15 and 36 on the GTN J1005 connector and there is no voltage. Pin 15 goes to PN101 pin W bootstrap XMT C. Pin 36 goes to PN101 pin V bootstrap XMT H. I have attached an interconnect for how I have it wired, the Garmin interconnect for the Bendix/King HSI, and the Collins wiring diagram.

Syncro heading sources do not supply the excitation voltage. This must be supplied externally via a 26VAC 400Hz external power inverter.