K9AY Loops with BPF

K9AY++ RX antenna system with BPFs, Preamp, Controller and much more

The K9AY is terminated loop RX 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. This set including the RF feeder box and the controller.

Main functions:

Low Noise RX antenna
Broadband
4 directions
Needs small room
Great for portable operations
50/75 ohm feed line tolerant
PREAMP with variable gain 0 to 18dB
Three switchable BPFs or BYPASS
RX protections / limiters in feeder and controller
Common-mode filter in feeder
RX source switch for TX and RX antenna

RF feeder box:

ONE versions for
1. Variable load resistor - RLOAD
2. Fixed load resistor - RLOAD
3. Easy to set by one JUMPER Manual page
Common-mode coax choke included.
PREAMP with variable gain 0 to 18dB
Three switchable BPFs or BYPASS
Front-end RF limiters
High voltage electrostatic protection with neon lamps.
High power IN/OUT protection
Safe to use it close to TX antenna
Easy to use LAN RJ-45 UTP CAT-6 cable. PLEASE read this instructions !!!
F/B depends also on loop instalation PLEASE read this instructions !!!
Stainless screws and nuts.
Quality PTFE SO-239 connector.
IP56 box.
Aluminium holder Picture
Size 20x15 cm (feeder).
Available as
- Assembled product with CONTROLLER - tested
- PCB

Controller:

Universal box for K9AY or 4-way Bi-Dir beverage system - there are BPFs and Preamp only in K9AY++ feeder, not for beverages!
If you want to use K9AY and 4-way beverage system with BPFs and Preamp, than this is better solution + simply K9AY
Including Bias tee AC/DC for RX antenna
Front End protections
RF power limiters in RX line
LED direction indicator 0 or 45 deg. Picture
Rload variable in 9 steps by the switch on the front panel.
Three BPFs and Bypass - 4 positions switch on the front panel.
Preamplifier switch and LED indicator.
RX SOURCE switch. Selecting TX or RX antenna for receiving. More: Picture and Manual

Parameters:

Supply voltage DC (AC for 4-way) 12 - 14 V up to 2 A
Preamplifier with NPN transistor 2N5109
Preamp BIAS current 10 to 70 mA
Gain: up to 18 dB - preset to 10 dB
NF < 3 dB
REAL OIP3 34 dBm
BPF loss lower than 1dB
TX power from TRX to TX antenna port up to 300 W
PTT IN/OUT - only loop, no delay, TX to GND
PTT logic is 5 V compatible (OM-power)

Antenna feeder block diagram:

Controller block diagram:

K9AY++ system includes:

RF box into the feed point of the ANT loops Picture
Aluminium holder Picture
Controller Picture
Total parcel weight abt 2 kg

All parts

Optional Common-mode current choke for coax and control cable

Optional box Link
Coax cable current isolator
Common mode current isolator also for control cable
You can use part of FTP CAT-5 cable from antenna to this optional box as GND system
Recommended to place it into the hamshack too. Picture

CMCC-CTRL for K9AY++

Band Pass Filters characteristic:

160m BPF

80m BPF

40m BPF

Band Pass Filters characteristic with preamplifier:

Videos

Users' photos

by Laci HA7JTR-HA7I

Download

K9AY
RF BOX Manual in WiKi	WiKi for RF BOX
CONTROLLER Manual in WiKi	WiKi for CONTROLLER
rev 1.8	sch	pcb	eagle115

We believe open source is a better way of doing things. View and download the Shield Schematic and PCB Kicad/Eagle CAD files, LibreCAD .DXF, or Inkscape .SVG files. The hardware designs are released under the Attribution-NonCommercial 2.0 Generic