Monday, December 28, 2015 IP remote hardware switch, based on Arduino

Intuitive remote control switching contains of two devices - controller and relay box - communicate via ethernet.
Suitably for realtime remote devices control, such as receiving antennas, power on/off for any devices, PTT, ...

Main functions:

  • 16 inputs:
    • 11 positions rotary switch,
    • 4 independent on/off switches with LED indication,
    • 1 press button.
  • 16 relay outputs:
    • 0,5A/125VAC, 1A/24VDC,
    • each output is signalised by own LED,
    • 1-11 with common line input.
  • TCP232 ethernet module configurable over network with windows software.
  • Settings in arduino source code.
  • Very low TCP bandwidth, only several units of bytes per second.
  • 1 to 11 outputs are protected as single out (antenna switching).
  • Network latency (delay) is indicated by LINKED LED. Latency is the same as LED off time.
  • Relay parking to define output (default 11), after network unavailable with preset delay. Typically used for grounded TRX input.
  • One control box is able to control up to eleven relay boards - CFG button reconfigure chip and redirect network (more in firmware configuration).
  • Open Arduino platform allows you to customize firmware.
  • 5V power voltage from USB mini plug.
  • Size: control 12x6x9cm, relay 22x3x7cm.
  • Weight: control 210g, relay 270g.

Saturday, December 26, 2015

10m 4x6el G0KSC H-frame stack - HD video

Please enjoy HD video of our 10m stack building...

Wednesday, December 23, 2015

Hybrid Low Pass filter,  part 1

   Thanks to Mikael SJ2W I started to play with hybrid LP filters. Why? Because it is easy design, high power ready, low insert loss and UFB notch. 

   What is it about... There are two coax stub filters, lambda/4 on notch frequency and inductor between. The stubs work as capacitor in the classic PI LP filter design. Look at the results:

Hybrid LP filter for 20m, notch on 10m:

Design: 2x coax abt 2,2m H1000, L is 4,5turns on 30mm

 Hybrid LP filter for 40m, notch on 20m:

Design: 2x coax abt 4.5m H1000, L is 7turns on 30mm