My Sandel SN3500 is linked to a Bendix King KLN94 GPS, my problem is the D_Bar on the Sandel stays static just right of center when in LEG mode on the 94, but becomes live in OBS mode. So if I do a direct to in LEG MODE say to an airport it should center when the course selecter on the Sandel is the same HDG on the 94, but it does not, just stays static it makes no difference if the Sandel is in Auto Slew mode or not, having used the two together for the last 10 years I should know how they work
When in VOR mode on the Sandel it all works as normal the D-Bar going to center and moving left & right. So is it the information from the 94 at fault or the Sandel, as it works in VOR mode I think if must be the KLN94 but could do with some help.
Have been in contact with Sandel and tried changing some of the information on the maintenance pages this did not help.
Has anyone a KLN94 for sale or one I could try in the UK?
Hoping someone has had the same trouble and can offer me some advise as to which unit is the problem.
If I understand correctly, this system used to work and then suddenly stopped?
Peter,
Yes worked fine together for 10 years
You need to probe the voltages on the SN3500’s analog deviation inputs, with the system in GPS mode. My old wiring diagram is here and this is the relevant bit
The comment “gps mode only” may not be applicable to you. It is correct for mine because the NAV signals (from the KX radios) come into the 3500 via “composite” (often incorrectly called “composite video” which is a different thing totally) which is just one wire.
A modern GPS can output the above analog signals digitally via ARINC429.
It could be the KLN94’s outputs are blown, but more likely a duff connection.
