DK5CZデザイン AMA マグネティックループアンテナ 'Käferlein'(日本語拡充中)

Mr. C. Käferlein (DK5CZ, Darmstadt) によるAMAマグネティックループアンテナは世界中で広く知られています。Funktechnik Beese (Darmstadt)で生産されていましたが、2016年、弊社が同事業の権利を得て、生産を継続することになりました。

AMA マグネティックループアンテナ - 基本的構造

AMA41 AMA 41 Magnetic Loop

The main feature of a magnetic loop is it's comparably small size in relaion to the wavelength. This makes this type of antenna very attarctive to many radio amateurs with little space for aerials. The tuning is done with a high voltage caüacitor in the loop, which is made from aluminium tubing. For best convenience the capacitor is tuned remotely by an electric motor.

Due to the physical principle of the loop antennas, these antennas have a very low radiation resistance. To achieve a good efficiency the losses in the antenna must be reduced as much as possible. This leads to the following construction requirements for AMA magnetic loop antennas:

  • Eine magnetische Antenne muss für den Betrieb im Freien wetterfest sein. Die AMA-Antennen werden wetterfest für eine vertikale Montage gebaut. Der Schutztopf für die Abstimmeinheit besteht aus glasfaserverstärktem Kunststoff (GFK) und ist somit UV- und witterungsbeständig, elektrisch und thermisch isolierend sowie elektromagnetisch transparent.
  • A magnetic loop antenna must be weatherproof for operation outside a building. The selection of materials and construction of the joints are of high importance. By many practical experiments the best suitable materials have been selected.
  • The tube of the loop and the tuning capacitor must be constructed very robust, to avoid fluctuations of the inductivity and capacity and therefore fluctuations of the resonant frequency. Besides the mechanical stability the tuning capacitor must be built with thick plates, a solid axle and large electrical contacts to prevent heating from the high electrical currents. The also keeps losses at a minimum.
  • For a precise tuning an accurate and continues mechanical drive, free of play, should be used. This mechanical drive must work reliably under all weather influences.

For best radiation symmetry we will use a symmetric coupling with a secondary loop.

  • The magnetic loop antenna should withstand excess power without permanent damage. This requires that the insulating material of the capacitor is resistive against high voltages, leak currents and arcing. When the antenna is accidentially overloaded there will only be a flash arc between the capacitor plates, but the antenna itself will not be damaged.

AMA ループアンテナ ラインナップ

AMA 45 Loop

元来、AMAループアンテナはいろいろなモデルがありましたが、弊社から販売するにあたって、どのようなモデルに需要があるか等、検討してきました。その結果、当初は以下のモデルに絞って販売を開始することにしました。ラインナップの拡大については今後検討していきます。


Käferlein AMA Magnetic Loops
AMA21DH AMA31D AMA41 AMA45D AMA42DH AMA85 AMA87 AMA82 AMA84DH AMA163 AMA164
Diameter 0.8 0.8 0.8 1.3 1.7 0.8 1.3 1.7 3.4 1.7 3.4 m
Max. Power 500 250 100 250 500 100 100 100 500 100 100 W
Bands 160 m 160 160
80 m 80 80 80 80 80 80
40 m 40 40 40 40 40 40 40 40 40
30 m 30 30 30 30 30 30 30 30
20 m 20 20 20 20 20 20 20 20
17 m 17 17 17 17 17 17
15 m 15 15 15 15 15
12 m 12 12 12
10 m 10 10 10
Gain
[1]
160 m -10.9 -5.8 dBi
80 m -13.5 -6.9 -4.7 0.2 -4.8 0.2 dBi
40 m -4.9 -1.0 0.4 -4.9 -1.0 0.4 1.6 0.4 1.6 dBi
30 m -1.3 -1.3 0.8 1.3 -1.3 0.8 1.3 1.3 dBi
20 m 0.6 0.6 0.6 1.4 1.6 0.6 1.4 1.6 dBi
17 m 1.2 1.2 1.2 1.6 1.2 1.6 dBi
15 m 1.4 1.4 1.4 1.7 1.4 dBi
12 m 1.6 1.6 1.6 dBi
10 m 1.7 1.7 1.7 dBi
Efficiency
[1]
160 m 2 17 %
80 m 2 10 22 69 22 69 %
40 m 21 53 72 21 53 72 95 72 95 %
30 m 49 49 79 90 49 79 90 89 %
20 m 76 76 76 92 96 76 92 96 %
17 m 88 88 88 96 88 96 %
15 m 92 92 92 97 92 %
12 m 95 95 95 %
10 m 97 97 97 %
Bandwidth
(VSWR 2:1) [2]
160 m 3 4 kHz
80 m 4 3 4 9 4 9 kHz
40 m 7 11 12 10 11 12 28 15 28 kHz
30 m 11 11 22 26 17 23 26 33 kHz
20 m 20 20 24 41 38 33 46 45 kHz
17 m 32 32 36 65 49 75 kHz
15 m 42 42 53 87 68 kHz
12 m 62 62 80 kHz
10 m 80 80 97 kHz
Order No. 11255.21DH 11255.31D 11255.41 11255.45 11255.42DH 11255.85 11255.87 11255.82 11255.84DH 11255.163 11255.164

[1]: Theoretical values by Ch. Käferlein DK5CZ, based on Magnetic Loop calculations DL2FA
[2]: empirical mean value

AMA Loop Antennen Steuergerät AMA Loop Controller

AMAマグネティックループアンテナの動作には、DC13.5V、最大250mAが必要です。DCケーブルは付属しますが、電源は別途、ご用意ください。コントローラーからアンテナまでのコントロールケーブル(2線式)も別途、ご用意ください。0.75mm² 径のワイヤで十分です。

  • 製品に含まれるもの
  • アンテナ本体
  • マストクランプ(垂直取付用。60mm径まで可)
  • コントローラー
  • コントローラー用DCケーブル
  • コントロールケーブル用コネクタ (Hirschmann STAS200 to the antenna, 3.5mm mono phone plug to the controller)
  • 取扱い説明書(英独)

AMAループアンテナは受注生産品です。納期についてはお問い合わせください

Order No.
11255.21DH AMA21 1280.00 € Buy now Not in stock, ordered only on customer request, delay c. 25 days.
11255.31D AMA31D 1090.00 € Buy now Not in stock, ordered only on customer request, delay c. 25 days.
11255.41 AMA41 1090.00 € Buy now Not in stock, back in 25 days
11255.45D AMA45 1370.00 € Buy now Not in stock, ordered only on customer request, delay c. 25 days.
11255.42DH AMA42DH 1490.00 € Buy now Not in stock, ordered only on customer request, delay c. 25 days.
11255.85 AMA85 1250.00 € Buy now Not in stock, ordered only on customer request, delay c. 25 days.
11255.87 AMA87 1350.00 € Buy now Not in stock, ordered only on customer request, delay c. 25 days.
11255.82 AMA82 1430.00 € Buy now Not in stock, ordered only on customer request, delay c. 25 days.
11255.84DH AMA84DH 1850.00 € Buy now Not in stock, ordered only on customer request, delay c. 25 days.
11255.163 AMA163 1690.00 € Buy now Not in stock, ordered only on customer request, delay c. 25 days.
11255.164 AMA164 1750.00 € Buy now Not in stock, ordered only on customer request, delay c. 25 days.
11255.CONTRO AMA Loop Controller only 149.00 € Buy now In stock, shipped in 1 or two days.
送料について
Download: AMA assembly instructions and manual (PDF, DE, 530KB)
Download: AMA brochure (PDF, DE, 1.8MB)

Double wire control cable

Double wire control cable, 0.75mm² cross section, black PVC coating. Suitable for the control of magnetic loops that require only two wires (AMA Käferlein Loops or similar).

Order No.
40059.50 50m Double wire control cable, 0.75mm² cross section, black 28.00 € Unfortunately this product is not available anymore. Sorry.
送料について