Antenna Info Page

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Antenna Information Page

Wind Dancers offers you the following information summary concerning this new product:

Price for the communication/navigation/ELT antenna is $125
Permanent installation is inside the airframe and is done with common adhesive
Price for the transponder antenna is $99
Lifetime guarantee (we will repair or replace the original owner's antenna)
Custom designs can be fabricated to fit special airframe needs
(one time tooling charges will be added to the cost)
Antenna weights are less than half the weight of conventional antennas

The VHF antennas, 5T and 5I, differ only in the location of the BNC connection. The 5T is configured to allow the coax cable to be routed flat along the mounting surface of the airframe. This antenna model would be appropriate for a composite aircraft where the antenna would be mounted in the fuselage or fin and the coax would be close to the skin and be attached periodically for strain relief. In either case, the antenna can be used as a retrofit on in service aircraft or in new installations.

The 5I series has the BNC connection positioned so that the coax cable would route out and away from the antenna mounting surface. This configuration is offered for antenna installations such as wing tips of fabric aircraft. If the antenna is mounted on the inside of the tip, the coax route is directly inward toward the wing root and the BNC connection is located near the spar to provide support for the cable.

Both antennas are identical in their electrical performance.

Fabric airframes can use this antenna in either the fuselage or the wing. Silver dope is not a problem with this antenna, however, attention must be given to the attachment of the antenna to the airframe to optimize performance. In a wing installation, attachment to a wooden rib or wooden spar is a must. In the fuselage, behind the seats in the tail cone is best. Here it is best to keep the antenna away from the metal structure.

For those builders who want to permanently build the antenna into their aircraft in difficult to reach locations, we offer any of the models without the BNC connector but with a length of coax cable manufactured with the antenna. We do this to eliminate the possibility of connector degradation over the lifetime of the aircraft. The cost for this special option is 50 cents per foot of coax using the light weight RG174/U or the standard RG58/U. These assemblies are custom manufactured and cannot be delivered from stock. Call for delivery times.

FAQs

What cable length is recommended for the antenna ?
Any length can be used. This antenna is impedance matched to 50 ohms to allow
you to use any length required.

Can I use it in the plastic or fiberglass wingtip of a metal airplane ?
Yes, but the antenna must be as far from the metal wing as possible.

Will the strobes cause interference ?
It is possible to couple the strobe audio squeal into the VHF radio. This
happens when the antenna is close (about a foot) to the strobe.

I thought the com antenna has to be vertical to work.
For maximum sensitivity, this is best. The VHF-5 antenna has a higher gain
than others but still when mounted in the horizontal plane the resultant
sensitivity is reduced but useable.

Can I mount the antenna on a metal part of my airframe?
No ! This antenna works best when separated from all large metal objects.
Mounting it on any metal destroys its antenna properties.

Some people have good operation with a ground plane working with their antenna,
does this one do the same?
No, any ground plane will destroy the effectiveness of this antenna.

My fabric airframe is completed, where is the best location for the antenna?
Mount it on a wood brace in the fuselage behind the cockpit. Fasten one end to
a location on the lower part of the fuselage frame corner. Then fasten the
other end to the opposite or diagonal part of the inside of the upper frame
corner. Fasten the antenna to this installed piece of wood.

Should I be careful of the angles at which I mount this wood?
No. As long as the antenna is in the same plane as the plane of rotation of
your propeller, it'll work.

What happens if I mount the antenna on one of my wood stringers on the fuselage?
The maximum range will always be off to the sides and the minimum range will be
ahead and behind you.

What happens if I mount the antenna on my wood spar in the wing?
The maximum range will always be ahead and behind you and the minimum range
will off to the sides.

What if the antenna has to be mounted with a bend to fit in the space I want to
use?
Curving the antenna will fill in those minimum range areas mentioned above at
the slight expense of the maximum range.

Can't I have both?
No, only a fixed amount of energy can be radiated. If you redirect energy to
fill in holes in the pattern you must remove some from one part of the
radiation pattern to fill in the other.

Why is it so long compared to others?
This is a dipole which is half wave length long and makes it about twice as
long as quarter wave antennas.

Can this be made shorter ?
No, it must be used as manufactured. If it is cut to fit, it will be destroyed.

Do I need a 337 ?
Perhaps. This is between you, your IA, and the local FAA. It mounts inside
and so does not alter the airflow, it attaches with adhesive so no holes or
alterations are required for the airframe mount, and it is too light weight to
affect weight and balance.

Will this work on my canopy?
Yes, but keep it as far from the metal frame as practical.

Why do I have to keep it away from metal things?
Any metal alters the characteristics of the tuning and pattern in unpredictable
ways. Each airframe installation is different, so we recommend that you use
tape and experiment with locations until you are satisfied with the operation.

Where is a good location in my fiberglass fuselage?
Put the com antennas on either side in the tail cone, & if the fuselage isn't
tall enough bend the antennas to resemble the letter"C". If you are using two,
stagger them on opposite sides and try to have about 24 inches or more in the
stagger.

Why haven't I seen this type of antenna previously?
This design has been in operation since 1981 but in response to consumer demand they are now being produced for the non-metal airframe market.

DIAGRAMS

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