Issue with HSI & KSN770

Jmcmanna

Pre-takeoff checklist
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Mar 9, 2014
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Southern WI
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Jmcmanna
I recently bought an Arrow with a KSN770

A few weeks ago ground control had a hard time hearing me on Comm 1. I switched to Comm 2 on the ground which they said was much better. Don’t notice a difference in the air.

Today I was practicing for an IPC and intended to track inbound to a VOR and hold on a radial/dme for fun. See attached picture. Nav1 gave me full deflection and a FROM flag while Nav2 was locked on and a TO flag.

I did an ILS approach. The localizer seemed to work normally, but the GS showed that I was on the GS, even when well above or below the glide slope.

I thought it was the HSI (Century 1000), but it seems like the KSN770 is the common piece of equipment with all of the NAV and COMM problems (yes, I used VLOC mode for the VOR/ILS tracking).

I am looking for wild speculation on what the issue might be. I bought the plane a month ago and it came with the KSN770. I realize it isn’t the most popular GPS/NAV/COMM, but I have been doing a lot of practice with it and dont want to spend a fortune to replace it.
 

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Nav2 was correct

I can’t make it Saturday morning, unfortunately I have to work.
 
How far away is the shop that did the installation?
 
It was done by a previous owner. I don’t have the logbooks with me at the moment, but I believe it was several states away. There is an avionics shop nearby that I am going to make time to visit.
 
@Jmcmanna,

I'll get this over to Shane Pheleps who is our KSN 770 guru in tech support.

Can you message me your phone number and I'll have him call you.

Look forward to hearing from you,

Steve
 
Thanks Steve! I pm’d my phone number. I appreciate the help!
 
Jim, Ref the comm issue; might it be that your comm 1 uses a belly mounted antenna vs comm 2 a top mount? Then shadowing would be the culprit since in flight you don't notice a difference. An avionics shop's "test box" will quickly show which nav system is correct. Also might be a nav antenna "splitter" cable to the suspect nav. If cable is RG-58 it could be deteriorated which is common. Or a simple connector issue...
 
Okay, cool! I am waiting on a call back from Bendix, hopefully they can give me some things to look for as well.
 
@Jmcmanna,

I'll get this over to Shane Pheleps who is our KSN 770 guru in tech support.

Can you message me your phone number and I'll have him call you.

Look forward to hearing from you,

Steve

I talked to Shane today on the phone, thank you for setting that up! He gave me some info which I think will help track down the problem when I take it in.
 
I talked to Shane today on the phone, thank you for setting that up! He gave me some info which I think will help track down the problem when I take it in.

Very good to see B-K getting more purposeful in support - after years of saying they wanted to revive the business, perhaps this is evidence of the commitment.

@Steve P - thanks!
 
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