NAV Antenna Installation

So I’m finally back with a new post.  The last several weeks have been rather hectic around here, starting with a trip to Oshkosh (awesome), followed by weeks of the annual inspection on the Tri-Pacer (not quite as awesome), culminating in  hurricane Irene generally making a mess out of things (not awesome at all, my man cave basement is toast!). Now we’re back to building most days, though the remnants of a tropical storm are rolling through southern Maryland as I type this. Time to try to get the blog back on track of keeping up with us. The activities described below took place around June 18th, 2011.

Back in the end of June, we were getting ready to fiberglass the bottom of the fuselage, and the last task in our way was installation of antennas in the bottom. Some people have put as many as 3 different antennas in the fuselage bottom, I’ve elected to keep it simple and just put a NAV antenna down there.  We can get glideslope by building a splitter for a NAV antenna if we decide we need it, and marker beacons are quickly becoming a thing of the past.

I had ordered the supplies for building the antennas for the plane long in advance from Jim Weir, thinking that there may be a long lead time. The lead time turned out to be too long for my liking, and I wound up buying the copper tape, coax cable, and torroids from Aircraft Spruce.  Do this. Do not bother with RST Engineering.  2 months after I had installed this antenna, I got a refund from Jim, with a note expressing his regrets at having not been able to complete my order in a timely fashion.  There are many more people who have reported similar experiences on the mailing list.

Anyway, the first thing I did was draw 2 lines 45 degrees to the centerline, locating the nav antenna more or less in the plans location. I then laid the proper lengths of copper tape on the lines, and drew a path for the coax that took it to the back side of the instrument panel, just off center. I routed out this line, so that the top of the coax would sit just flush with the foam, and so there was a recession for the torroids after they were shrink wrapped in place.  I then simply soldered the tape to the coax, one leg to the core wire, and one to the shielding.  I did a continuity test on each leg, saw that all was well, and microed everything in place.

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One Response to NAV Antenna Installation

  1. Dad says:

    Yay! New post!

    Guess you guys are getting back to normal, just in time for the next storm! 🙂

    Look forward to seeing more progress soon.

    –Dad

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