Antenna question

woodchucker

woodchucker

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woodchucker
Some planes have a long antenna connected from the fuselage to the vertical stabilizer. A look at AOPA flight training site states that older ADF receivers need a "sensing wire" to prevent 180 degree errors. Are these the same thing?

I actually asked another pilot who had one on the plane he was flying and he didn't know either... so as a new pilot I don't feel quite so bad. The training aircraft I flew in didn't have this.
 
woodchucker said:
Some planes have a long antenna connected from the fuselage to the vertical stabilizer. A look at AOPA flight training site states that older ADF receivers need a "sensing wire" to prevent 180 degree errors. Are these the same thing?
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Correct. Often the receiver that required it has been removed but nobody bothered to remove the wire.

Single engine aircraft permanently equipped for ocean crossings (or flight in the australian outback) sometimes have HF antennas strung from one of the wingtips to the tail and from there to the fuselage.
 
Had one on my twin ,first thing I got rid of,when I upgraded avionics.
 
I still had the insulator fitting for one of those long sense wires on my plane though it had been replaced with a "bump" style antenna. Both the fittings, the more modern ADF antenna, and the ADF itself went into the garbage when I redid the plane a few years back.
 
I had a Bendix T-12 ADF in my plane. It had both the long wire on top and a loop antenna on the belly.
 
My ADF and antenna are long gone. It was kind of fun to tune in an AM radio station with a baseball game and watch the ADF point directly at the broadcast antenna's location. Old school stuff.
 
Stewartb said:
My ADF and antenna are long gone. It was kind of fun to tune in an AM radio station with a baseball game and watch the ADF point directly at the broadcast antenna's location. Old school stuff.
Click to expand...

The ND state aeronautical directory lists the AM stations with their position relative to the next airport. If nothing else in your panel works, the ADF will still pick up a 10kW radio station from 100 miles out.
 
On Ag planes the wire goes from the wire cutting post in the center of the windshield to the top of the tail to deflect wires over the tail if you get too high.
 
woodchucker said:
A look at AOPA flight training site states that older ADF receivers need a "sensing wire" to prevent 180 degree errors.
Click to expand...

It is called the "sense" antenna to distinguish it from another necessary component of the ADF system called the "loop" antenna. I disagree with the 180 degree reasoning, but the true answer would take me half an hour to type out ...

.
 
Stewartb said:
My ADF and antenna are long gone. It was kind of fun to tune in an AM radio station with a baseball game and watch the ADF point directly at the broadcast antenna's location. Old school stuff.
Click to expand...

I have XM Radio for the ball games now.
 
BigBadLou said:
http://en.wikipedia.org/wiki/Loop_antenna
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"Antenna Engineering Handbook" (Jasik et al) Chapter 27 (Bolljahn/Granger) and Chapter 28 (Richardson), McGraw-Hill, 1961.

Krause also gives a very good description of the sense-loop arrangement but unfortunately his book is packed away getting ready to move to the new lab and is inaccessible.

Thanks,

Jim
 
So here is a question, the rules say you have to have a FCC license and AP to install avionics. Can anyone take the units and antennas out and update the weight and balance?
 
Are you asking who can legally amend the W&B for a certificated airplane?
 
Let's start with Owner wants to remove Loran unit and antenna and wiring. Loran is not on MEL, but listed on updated W&B with factory supported original W&B calculations
 
owner has read FAA-8083-30 Ch4 in particular page 4-32
 
yetti said:
Let's start with Owner wants to remove Loran unit and antenna and wiring. Loran is not on MEL, but listed on updated W&B with factory supported original W&B calculations
Click to expand...

You remove them, have an A&P reweigh the airplane and get an accurate W&B out of the deal.
 
yetti said:
So here is a question, the rules say you have to have a FCC license and AP to install avionics. Can anyone take the units and antennas out and update the weight and balance?
Click to expand...

The rules say nothing about an FCC license. The rules say nothing about having to have the P on your A&P. Yes, anyone can take the units out and update the w/b. However, an airframe mechanic must return the aircraft to service with a signature in the log.

Jim
 
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