The International Cessna 170 Association

Thin cork gasket material will work fine, as will nitrile sheet.

The look of the Narco is growing on me. The claims that it's a little lighter because of the absence of 25 feet of coax is very appealing. The fact that they can be had (and presumably restored to perfect functionality) for pennies compared to a new $400 Comant antenna is pretty nice as well.

Does the Narco also function as a glideslope antenna? Our 170 had a Narco up until the late 1970s, and there were a couple of unsightly antennas mounted in the front of the windscreen on the upper front fuselage skin that I understood to be glideslope antennas (but my dad thought they were old COM antennas). I'm not too excited to have more antennas than I really need.

The (old) antennas mounted in front of the windscreen on the "coaming" were usually ADF long wire, HF, and/or full-wave VHF antennas. They were not glide slope.

The Narco VOR antenna can be used with a "splitter" to sense glide-slope for your glideslope receiver.

I've got a nice Narco mast antenna all ready to install. Where does it go? Is there a drawing that shows the location?

On my plane, it's top center about 8" behind the center fuel vent.

bagarre wrote:On my plane, it's top center about 8" behind the center fuel vent.

And sure enough ... hey, what's THAT doing in the place where the VOR antenna is supposed to go???

Here is where mine is. It is so far back the back two mounting screws go through the carry through spar flange. As you can see my aircraft had another antenna in front of the Narco at one time. Like the venturi most of these where probably added after Cessna so their location could be anywhere. However it was a kit 051104-4 and that probably had instructions which might locate the "official" spot. If you look at the IPC there is one clue that might help you get it close without the instructions. Notice the VHF wire antenna, when installed, went over the top of the Narco. You can see from the A model IPC the locations of the terminal of this wire on top of the boot cowl. The wire should clear the windshield so running a chaulk line from the boot cowl up and over the Narco so there is window clearance should get you pretty close. I think DaveF's antenna location is closer to "correct" than mine.

What color should I paint my Narco mast? I'm thinking silver with a color in the lettering to match the airplane paint scheme. How were they originally painted?

The one I got off ebay was originally bare metal with black lettering that was over painted white with orange lettering (to match the guy's plane)

I stripped and re-painted it white to match my plane with black lettering.

Silver French Grey was a Cessna interior color. The original Narco antenna I have is that color with black Narco lettering.

Looked all over the forums and also my logs and for the life of me, I can't find the p/n for the Narco NAV antenna (the "whiskers" version, mine is installed in the vert stab). Does anyone happen to have this P/N and whether or not it picks up glideslope? My radio is a Narco 12d+ (i.e. has GS capability, but I don't have a GS CDI).

I'm pulling the Narco soon and putting in a GNS430 (non-WAAS) but wondering if the Narco whiskers antenna will work with the NAV functionality.

n3833v wrote:Just to stimulate thinking. Pointed forward could be a trash catcher such as anything flying from the cockpit, don't ask. Swept rearward any trash would fly off. ... John

OK, John... we’ve waited long-enough.... Whose bra was it?

bgiesbrecht wrote:Looked all over the forums and also my logs and for the life of me, I can't find the p/n for the Narco NAV antenna (the "whiskers" version, mine is installed in the vert stab). Does anyone happen to have this P/N and whether or not it picks up glideslope? My radio is a Narco 12d+ (i.e. has GS capability, but I don't have a GS CDI).

I'm pulling the Narco soon and putting in a GNS430 (non-WAAS) but wondering if the Narco whiskers antenna will work with the NAV functionality.

All VHF nav antennas should work with any nav receiver, and they should all receive glideslope. Any problems will be caused by bad coax or balun attached to the antenna. But a quarter-wave dipole is the same antenna to any receiver.

As far as the VOR antenna pointing forward or backward, there is a technical difference in the performance level the antenna would give. This is because of the shape of the reception cone created as I understand it from my electrical engineer friends who specialize in antenna design and radio wave transmission. I can't remember which way would be technically better. In reality it probably doesn't matter based on the fact you see them mounted both ways. The expensive SR 20 and 22s and one Seneca III I can currently see in the hanger, all have them pointed backward and of course Narco's antenna most often found on the 170 was also backward if that is any indicator which way to point the whiskers.

BTW I connected a Garmin 155 GPS VOR receiver to the whiskers I mounted on the tail of my 170 and had no issues. Can't remember whether whiskers forward or back on that project but believe I went forward.

I have the Narco antenna on top of the cabin - been there since 1952. I did remove and refurbish it in the 80's. Works great.
Of course, I'm of the opinion that you can't improve on the 170 - mines an "A", and I try to keep it as original as practical. Love the key switches, round instruments, etc. Works for me.