My plane was purchased with a cat-whisker type VOR antenna mounted atop the vertical fin. Stainless elements, looks like a Comant CI-157 but it's from the 70's and I can't find the receipt to tell make/model. I removed a KX145 and its rack and didn't install a nav radio. (It worked when removed, except the frequency selector readout failed and couldn't reliably tell what freq it was on.) Ran the nav antenna cable to a bulkhead connector on the panel so I could connect a jumper to my handheld Narco HT870. Tried it in flight, no reception. Rubber ducky works, but with this connection, nothing.

Queried internet for ideas. Best I could find, one element goes to center pin, one goes to ground. Ground is also the cable shield. Continuity test? OK, try it. Clip to port element, check to center pin on end of jumper, continuity. Check to shield, also continuity. Hmm. Clip to starboard element, check to center pin on end of jumper, continuity. Check to shield, ditto. Double hmm. Check jumper, nope, no continuity between center pin and ground. Check bulkhead connector, yep, continuity between center pin and ground. Triple hmmm.

I'm confused. My limited knowledge says no way can both the center pin and the shield go to ground and still deliver a signal to a radio. The fin tip is fiberglassed around the antenna and will have to be drilled/ground off to gain access to the connections on that end. Is there something else I should check before doing surgery, or is it really supposed to work that way?