K9AY Loop System Complete Mast and Wire Kit with Controller
AS-AYL-4 4 direction Low Band Receiving Antenna
AS-AYL-4 RX Loop Controller in water-proof housing (Preamp included) -
AS-AYL-4 MW Kit AYL-4 Mast and Wire Kit Includes 24' fiberglass mast, wire, stakes, radial ring, no ground rod, - requires controller above
Improved robust design of controller and outdoor box upgraded to NEMA- 4X
Upgraded controller, adds more flexibility and easier use
Mast /Antenna Kit is military grade hardware
Mast/Antenna Kit is rugged enough for permanent installations but also quickly deployed for DX-Peditions or Emcomm.
The Best Preamp/bandpass filter on the market. See specs and plots here
Termination of loop is done with temperature stable resistors vs a Vactrol, since Vactrols are unstable, easily damaged by surges and they drift with temperature changes. We reviewed using Vactrol terminations and rejected it as a poor design. See what Gary, K9AY says about Vactrol terminations in the FAQ.
The AS-AYL-4 Loop antenna consists of
1. Controller, the blue box above. It includes the pre-amplifier and bandpass filter.
2. Outdoor relay box that mounts on the antenna mast
3. AYL-4 Mast/Antenna kit, which includes a mast, wire loops, stakes and ground rod fixture.
or if you supply your own mast, we have
4. Wire Kit which has everything that the Mast/Antenna kit has except the mast. Very desirable for overseas shipments.
The AYL-4 Mast/Antenna Kit includes the following parts
Easy but secure installation portable, DX-Peditions or Permanent QTH.
Antenna type: Terminated loop
|Pattern: Cardioid, switched in four directions|
|Peak front-to-back: Greater than 20 dB, typically 30 dB|
Feedpoint impedance: 50 ohms nominal; low-loss transformer matching to the antenna
Frequency range: Very low frequencies to 8 MHz, using published dimensions. With preamp on, bandpass is limited to 1.8-5 MHz
|Direction change: Feedpoint/termination switching relays|
|Direction control: Connected with a 6-conductor control cable|
RF connection (antenna): SO-239 (UHF) connectors at control box and outdoor relay box
RF connection (radio): Phono connector output to receiver external antenna input
Termination Adjustment: Eight resistances from 340 to 680 ohms, selected by front-panel rotary switch
Power requirements: +12 to 15 VDC, 400 mA max., (provided by customer, to be fused at 0.5 A)
|Preamplifier: 15 dB gain, feedback type, using a silicon NPN transistor|
|Filter passband: ±2 dB from 1.80 to 4.5 MHz|
|Filter stopband: –55 dB at 7 MHz, –50 dB below 1450 kHz (typical)|
The AYL-4 K9AY Loop System requires approximately 18 feet in four directions from the center of the antenna, plus additional distance depending on the guying method. The base of the supporting pole and the ground rod are located at the center. With the AYL-WM kit, 18 feet in each of the four directions is required. The center support is 24 feet high, and must clear any objects above.
Plot of the K9AY loop Antenna Response.
- Measured Plot of the AS-AYL-4 Control Box -
- Amplifier and Filter Response
Preamp Switched On
Measured Plot of the AS-AYL-4 Relay Box
Matching Balun Transformer
Top Plot is the S11 Response with the Antenna terminated into 450 Ohms
Bottom Plot Shows a Return Loss of 25 dB into the Balun with 450 Ohms Termination
- Array Solutions£399.95(Inc VAT at 20.00%)