I helped a buddy troubleshoot his intermittent radio problems.
He has a blade type antenna installed, but doesn't recall the model. It is a pain to get to, we therefore haven't removed it yet. No markings are on the outside. I guess it is an older RAMI antenna but don't know for sure.
Anyways, I at first suspected corroded connectors, which however turned out to look like new. I then went on to measure the cable and the antenne with a multimeter: The cable checked out ok, but measured only around 0.6 Ohm between the center pin of the antenna's BNC connector center pin and the outer conductor.
Based on my knowledge of antennas I don't think this is is right but have to admit that I don't have much aircraft specific antenna experience. Two other antennas I measured for reference however had a resistance in the high MOhm range.
So - are we dealing with a dead antenna or might some circuit inside the antenna cause such a result?
Oliver
He has a blade type antenna installed, but doesn't recall the model. It is a pain to get to, we therefore haven't removed it yet. No markings are on the outside. I guess it is an older RAMI antenna but don't know for sure.
Anyways, I at first suspected corroded connectors, which however turned out to look like new. I then went on to measure the cable and the antenne with a multimeter: The cable checked out ok, but measured only around 0.6 Ohm between the center pin of the antenna's BNC connector center pin and the outer conductor.
Based on my knowledge of antennas I don't think this is is right but have to admit that I don't have much aircraft specific antenna experience. Two other antennas I measured for reference however had a resistance in the high MOhm range.
So - are we dealing with a dead antenna or might some circuit inside the antenna cause such a result?
Oliver