K9AY feeder with BPF

This revision is from 2018/09/13 18:19. You can Restore it.

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This is plastic box with the aluminium holder. Inside it, there is transformer with insulated windings, variable Rload, input and output protections. and in the middle, 160/80/40m BPF or bypass and 15dB preamp.

All you need is connect loops' wires, GND, coax cable and control cable (CAT-5 UTP or better FTP)

Connector description

  • There is standart RJ45 (ETHERNET) connector with shielding

  • Connector PIN description:

  • direction logic ( apply +12V for logic 1 )

Antenna GROUND

  • The K9AY antenna doesn't work without ground.
  • It loses the f/b directivity.
  • This means that it needs good ground!
  • A 4-foot ground rod (such as 3/4” diameter copper pipe) is often sufficient. If the earth is very dry, a longer

ground rod is advised, to reach permanently moist earth—or you may install four or more 15- to 20-foot long

radial wires for better coupling to ground. The grounded design of the K9AY Loop has several advantages over

ground-independent versions of the terminated loop (Pennant and Flag), including simpler switching, no

feedline isolation problems, and greater signal capture for the same size loops. source K9AY: AY Technologies

Rload FIXed or VARiable

  • With Jumper JP2 you can switch between FIXed or VARiable Rload.
  • If you short 1 and 2 than there is abt 450 Ohm fixed Rload. If you use controller with Rload controller, than switch to last position 9

Rload checking the resistance

  • Connect Ohm meter to this position and measure value vs input Rload VTL voltage - PIN 6 on RJ45 connector

Preamp BIAS SET check current and voltage

  • Connect Volt-meter to GND and jumper JP1. Measure voltage ( PREAMP ON ), it should be more than 11V. ( if you want HIGHer IP3, than it could be 15V / 80mA :) )
  • DISconnect jumper JP1 and connect mA meter on the pins ( 200mA scale is fine ). Turn with R4 multi-turn trimmer and set bias to 65 - 85mA. You can have a look at my measurements: 2N5109 OIP3 vs voltage and bias

Pramp GAIN

  • Total gain of PREAMP is around 18 dB.
  • With trimmer R6 you can set gain as you need.
  • There is variable ATT.
  • Gain can be set from 0dB to about 18dB.

Direction switching check

  • There are LEDs in the feeder box. You can check it easy there.
  • Switching matrix is under LEDs.

ToDo

  • Cable wiring circuits