K9AY++ RX antenna system with the Remote Control feature

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The K9AY is terminated loop antenna. It consists of a wire loop of any convenient shape (diamond, delta, etc), hung from a single support and with a ground rod at the bottom. A 9:1 impedance-matching transformer is connected from one end of the loop to the ground and a terminating resistor is connected the other end of the loop to the ground. Antenna has got Band Pass Filters and Preamplifier in the feed point of the loops. It is advantage of filtering and amplification small signals directly from antenna. This antenna is directional. Favoring signals are arriving from the feed point end. You can also change the antenna far field by changing RLOAD (RTERM) of the loop. Feeder box consists of directional switch relay, variable and fixed Rload, matching transformer, front end protections, BPFs for 3 low bands, preamplifier and common-mode filter. Controller allows you to switch all this features over one control cable (8 wires) and there is also Remote Control DB-15M connector for external remote control. This set includes the RF feeder box and the controller.

Main functions:

RF feeder box:

Antenna feeder block diagram:

K9AY matching unit


Remote Control notes:

Controller block diagram:

K9AY comparation
K9AY comparation K9AY/4-WAY controller is for this beverage system.

K9AY controller with RC block diagram


K9AY++ system includes:

Optional Common-mode current choke for coax and control cable


Band Pass Filters characteristic:

160m BPF

80m BPF

40m BPF

Band Pass Filters characteristic with preamplifier:

BPF 160m & Preamp 10 dB

BPF 80m & Preamp 10 dB

BPF 40m & Preamp 10 dB

Bypass & Preamp 10 dB



RF BOX Manual in WiKi WiKi for RF feeder BOX
RF feeder rev. 2.3 sch pcb 42
Controller connector board rev. 3.2 sch pcb 43
RX/TX switch board rev. 1.1 sch pcb 40
Front Panel board rev. 1.2 RC sch pcb pcb
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