View Full Version : KX165 Nav/Comm
helicopter-redeye
9th Dec 2005, 10:09
Can a KX165 Nav Comm (VOR/LOC/GS) physically drive more than one indicator at the same time (with the same indications being shown on both instruments at the same time)?
Why? More than one person looking at the same data but from different places in the cockpit.
Views/ opinions/ facts?
h-r:)
L-Band
9th Dec 2005, 15:25
The KX 165 will drive another indicator, however this will be a repeater of the primary indicator and will have no OBS information.
What decides the CDI bar deflection? Is it done within the instrument, or is it done by the NAV radio driving it? If the former, driving more than one CDI should work.
However any half competent avionics man should know the answer.
A and C
9th Dec 2005, 20:34
The KX165(A) cauculates the CDI position in the radio box, the radial selected on the OBS is sent to the KX165 via syncro lines.
Without the drawings in front of me I cant be sure but I think if you fitted a second indicator with a LOC converter and powered it from the VOR/LOC composite line it might work.
The reason all the calculation happens inside the KX165 (A) is that it is intended for use with a HSI and HSI 's do not usualy have room for a LOC converter inside the box.
IO540
I'm airframe & engine !
Big Pistons Forever
9th Dec 2005, 21:55
I have seen many installations where the 165 drives a trackbar/GS on the HSI and a VOR RMI needle at the same time.
A and C
9th Dec 2005, 22:05
The RMI is driven from the VOR/LOC composite line.
IO540
10th Dec 2005, 06:33
I have seen many installations where the 165 drives a trackbar/GS on the HSI and a VOR RMI needle at the same time.
Yes, I have that and it works :O
The way avionics works is quite bizzare; must be a legacy of somebody wanting to sell more "boxes" decades ago... no reason why one cannot feed the current radial (in whatever form, quadrature, gray code, or whatever) into a CDI and have it determine the bar deflection (and the flags) purely from that input, and from what it's OBS is set to.
Come to think of it, if the CDI bar is done externally to the instrument, why are the flags done internally? The flags are also resolved purely from the received radial and the OBS setting, nothing else.
It may be simpler if the OP just wants a CDI for a VOR and isn't after a LOC-capable indicator. LOC/ILS would be something else, because on a LOC or ILS approach the bar deflection IS done by the NAV receiver; the OBS (contrary to what a lot of IR pilots have been taught) doesn't do anything.
helicopter-redeye
10th Dec 2005, 17:09
Thank you Gentlemen, helps to frame the tender document to give to avionics engineers.
If anybody is interested in delivering the service, please PM me.
h-r:)