ARLA/CLUSTER: Antena Coaxial Alpha Loop dos 10 aos 40m, a pensar nas actividades SOTA

[João Costa > CT1FBF]

*10-40 Meter Coaxial Alpha Loop
<http://www.cqdx.ru/ham/new-equipment/10-40-meter-coaxial-alpha-loop/>*


<http://www.cqdx.ru/ham/wp-content/uploads/2015/10/Alpha_Coaxial_Loop_Antenna.jpg>

The 3+ foot high and wide Coaxial Alpha Loop Antenna is perfect for those
operating Condo, SOTA, Beach, RADAR, or any place you need a High-Q
directional HF antenna with low noise capabilities designed into the
system. The LMR-400 based element of the Alpha Loop offers you a light
antenna in a small package, which deploys in 60 seconds!

The Coaxial Alpha Loop Antenna is uniquely mountable on the included
tripod, providing you with the greatest ease of deployment, use, and
effective efficiency ever made available. We are always advancing our
antenna systems, so starting 9/28/15, this antenna will now come with the
built-in SWR Indicator!

TUNING
Here is a video presentation on how to tune the 10-40 meter Coaxial Alpha
Loop Antenna

SWR demonstration from 10-40 meters:
Here is a video presentation of another way to tune the Alpha Coaxial Loop
Antenna:

Included:
Outer Loop with Continuous frequency coverage from 7 to 29.7 MHz made of
LMR-400 that is 100% Made In The U.S.A. using crimped & soldered Silver
Plated PL-259s, which is the same technique used to build MIL-SPEC
connections for the U.S. Military
Maximum Power – 12 watts PEP SSB
Duffel Bag dimensions in inches – 12″x12″x3.5″
Feedline – 50 ohm Ultra RG58/u coax with BNC connector on coax
Adapter – BNC female to PL-259
Mount – Integrated 3/8×24 bolt & 1/4×20 nut that is milled in the U.S.A.
Tripod – 3 feet Silver plated SO-239s are milled and formed 100% in the
U.S.A.
High-voltage boxes are of a high quality and are 100% Made In The U.S.A.
The Variable Air Capacitor is made of raw materials from and assembled in
the U.S.A.
All other parts, even the black plastic knob used to tune and the solder is
from the U.S.A.

Weight: Antenna (1.8 pounds,) Tripod (1 pound), & Canvas Duffle bag (.8
pounds)

STANDARD
Assembles and dissembles from the included field bag in 60 seconds. As this
antenna is a loop, there are no taps on coils and no counterpoise wires
needed. Has a built in tuner that allows you to easily match the antenna
for transmit and receive from 7 to 29.7 MHz (40 Meters through 10 Meters).
High noise rejection is also one of the favorite features of this antenna
for many operators in RFI prone environments. Includes a coax feed line
with BNC Connector plus BNC to PL-259 adapter.

HOW DOES IT WORK?
The Coaxial Alpha Loop Antenna appears as a large resonant circuit to your
transceiver. The loop is a large single turn inductor of the circuit. Due
to the large size of the inductor, radiation of your signal very easily
takes place.

INCREASED EFFICIENCY
To increase overall ERP, the variable air capacitor is placed inside the
loop. Doing this captures the power from the variable air capacitor inside
the loop, where the power that would normally be lost to ground can be
recycled. Other designs place the capacitor below the loop where losses
would be radiated on the outside of the loop toward the ground.

Better coupling is the result of the Coaxial Alpha Loop Antenna using a
shielded coupling loop. Where return-loss (VNA parameter S11) increases
rapidly when the distance is increased from 0 to 2-3 cm (1″), then becomes
flat with further increase in distance. Over the initial distance increase,
the shielded coupling loops had about 6 dB less return-loss, i.e., better
coupling. Additionally, shielded coupling loops had slightly better SWR
than the unshielded coupling loops. bullet

Link <https://amateurradiostore.com/>

Price: $299.00 USD


Fonte: Sparky\'s World of Amateur Radio.
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