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n38139

Well Known Member
I am not sure where this needs to be, I didn't see a "NAV" Forum. I have a wingtip mounted NAV antenna and get lousy ILS reception. Anybody have any idea what I can do to check or possibly fix my problems. I have checked the antenna cable and connections and they are OK.

thanks,
 
n38139 said:
I am not sure where this needs to be, I didn't see a "NAV" Forum. I have a wingtip mounted NAV antenna and get lousy ILS reception. Anybody have any idea what I can do to check or possibly fix my problems. I have checked the antenna cable and connections and they are OK.

thanks,
Click to expand...

A search using the string "archer and sportcraft" pulled up this thread which you will find useful:

http://www.vansairforce.com/community/showthread.php?t=40633&highlight=archer+sportcraft

The search engine is a great tool. :)
 
I never had much luck with the Archer wingtip antenna for ILS/LOC operations. And when HID lights are mounted in close proximity it made for even worse performance in my airplane. I mounted a Comant CI 159 on the belly skin in the tail area and it works great. YMMV.
 
Opposite opinion

My Archer NAV antenna with my SL-30 works extremely well. I do have wingtip lights, strobes.
 
seems like grouding is an isue

I like to roll a strip of copper foil tape around the lip of the wing tip before I rivet the nut plates and antenna to the win tip. Make sure there is no paint on the inside of the wing skin that the antenna and the copper tape touches.
 
ILS Antenna

Would it help to put an external ILS antenna like a Comant CI-104? Can you do that with an SL30, I am out of my knowledge base here.

SS
 
Ground is important

If you have poor performance from your wingtip Archer style antenna, you most likely have a poor bond to the skin. The element that is parallel to the rib must be bonded to the wing skin to form the ground plane. I use a small ground strap as well to ensure good contact. Take a look to be sure you have the coax braid attached to the bonded side of the antenna. Make sure the antenna radiator is not shorted to the bonded side, and that the insulator at the coax connector is installed correctly. Nothing at all metallic can cross over the radiator, and it is recommended that you run all of your wiring along the base leg of the radiatior parallel to the wing leading edge. The entire shebang should be installed so it rest's on the bottom of the wingtip.
Check your coax with a meter to be sure it is not shorted or open.
I'll bet you will find something here, as mine will pick up a VOR from 30 NM on the ground!! (sometimes)
That being said, never had any luck with the Archer comm.....

Regards,
Chris
 
carguy614 said:
If you have poor performance from your wingtip Archer style antenna, you most likely have a poor bond to the skin. The element that is parallel to the rib must be bonded to the wing skin to form the ground plane. I use a small ground strap as well to ensure good contact. Take a look to be sure you have the coax braid attached to the bonded side of the antenna. Make sure the antenna radiator is not shorted to the bonded side, and that the insulator at the coax connector is installed correctly. Nothing at all metallic can cross over the radiator, and it is recommended that you run all of your wiring along the base leg of the radiatior parallel to the wing leading edge. The entire shebang should be installed so it rest's on the bottom of the wingtip.
Check your coax with a meter to be sure it is not shorted or open.
I'll bet you will find something here, as mine will pick up a VOR from 30 NM on the ground!! (sometimes)
That being said, never had any luck with the Archer comm.....
Click to expand...

I did all of the things that you mentioned and still I had what I viewed as unacceptable performance. With the SL30 connected to the Archer antenna I too could pick up VOR stations on the ground. The performance that I found to be unacceptable was:

1. HID lighting mounted in close proximity to the antenna (Duckworks leading edge landing light) would significantly reduce the range of the radio.

2. Even with the HID lights off, depending on the orientation of the aircaft to LOC/GS transmitters, the SL30 would either be tuned in very well, or reception would be somewhat sporadic. This issue in particular, to me at least, was unacceptable for IFR operations.

The installation of a cat whisker antenna solved these problems. I suppose it could have been an issue with my installation that I overlooked that was causing the trouble. But I spent a lot of time troubleshooting which involved removing and reinstalling the wing tip multiple times (a real pita). I finally gave up and went with the Comant antenna and have been trouble free ever since. YMMV
 
Nav Antenna

My VOR seems to be OK, not great but my ILS is worthless. Will start taking things apart and see if I can find a problem
 
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