Glide slope problems!

[engtr01]

I have a kx155 with a ki209a indicator. If have owned my plane for 8 years, and the glide slope worked for about the first 6 months and then stopped working. Things that do work from the dipole antenna: localizer, VOR, and the glide slope flag gets withdrawn. Things I’ve checked: Balun connections to antenna, balun ground, connections on triplexer, tested indicator and got up and down deflection of needle. Would I be correct by assuming since I have localizer/VOR signal that I have glide slope signal to my triplexer? Any ideas or help would be sincerely appreciated!

Russ

 

[bnt83]

I have a kx155 with a ki209a indicator. If have owned my plane for 8 years, and the glide slope worked for about the first 6 months and then stopped working. Things that do work from the dipole antenna: localizer, VOR, and the glide slope flag gets withdrawn. Things I’ve checked: Balun connections to antenna, balun ground, connections on triplexer, tested indicator and got up and down deflection of needle. Would I be correct by assuming since I have localizer/VOR signal that I have glide slope signal to my triplexer? Any ideas or help would be sincerely appreciated!

Russ

Almost every old Cessna out there uses the vertical stabilizer mounted V antenna to drive both the VOR and GS inputs on a receiver. The glide slope wavelength a 1/3 of the VOR so the antenna works for both.

What is the part number on the spltter? Who made it?

I've had a splitter hooked up wrong before, the GS output to the VOR receiver and the VOR output hooked to the GS receiver, no it didn't work.

 

[engtr01]

Almost every old Cessna out there uses the vertical stabilizer mounted V antenna to drive both the VOR and GS inputs on a receiver. The glide slope wavelength a 1/3 of the VOR so the antenna works for both.

What is the part number on the spltter? Who made it?

I've had a splitter hooked up wrong before, the GS output to the VOR receiver and the VOR output hooked to the GS receiver, no it didn't work.

View attachment 60573

Well I can tell you it’s very old...there is no tag on the triplexer, the positions are stamped in the metal case and I’m sure it’s hooked up right. I wonder if there is a way to test it

 

[bnt83]

Well I can tell you it’s very old...there is no tag on the triplexer, the positions are stamped in the metal case and I’m sure it’s hooked up right. I wonder if there is a way to test it

Hook the GS receiver directly to the antenna and go fly an operating (one that is not busted) ILS?

 

[weirdjim]

Listen to the OP. The glide slope flag gets dropped. For this to happen the glide slope receiver has to be operational and outputting a glide slope audio signal. Something has gone woxo inside of the indicator head.

Perhaps the question should be asked of the OP to be SURE that the GS flag goes away when tuned to an ILS signal and is raised otherwise.

I stand corrected. The OP said that the KI-209 glideslope needle went up and down with the appropriate current. Since the KX-155 has the glideslope receiver internal, the problem is in the 155, not the nav head. But the flag going up and down certainly eliminates the antenna, coupler, and coax from the equation. Something internal in the 155 glideslope receiver is the woxo, not the nav head. jw

Jim

 

[weirdjim]

See my edit. Thanks jw

 

[engtr01]

Thanks to all who posted ideas! They were much appreciated! I decided to do a continuity test of the four wires that go from the tray connector of the kx155 to the ki209a, and sure enough I had problems in the form of bad Crimping/connection with the Molex connectors at the back of the tray. I would wiggle the wires and everything would work...I have some Molex connectors on order. In the meantime I put a tiny drop of solder in each connector where the wire is crimped and everything works fine! Thanks for the help

Russ