Friday, February 15, 2013

My Satellite setup

Recently I have been active in the SO-50 ham satellite.


This is my early setup: (I say early , because it's in constant renovation... I've some ideas and project ongoing...)


Radios:
- 70 cm channelized Kenwood TK860 (top of the setup, adjusted for the 436 Mhz ham band)
- 2m Alinco DR-130T with subtone module (in the middle)
- 2m Yaesu FT-23R (laying on the right-center of the image)
- Power Supply is a commercial switching PS from a chineese manufacturer capable of adjustable 10 to 15 volts at 25 amperes (aluminum case at the bottom)

I use 5 channels for the downlink on 70cm for doppler corrections, the picture was taken with my radios at the end of the pass, that's why it's on channel five

1 = - 10 Khz
2 = -5 Khz
3 = Center freq.
4 = + 5Khz
5 = + 10 Khz




Antennas:
- 70cm 6 element home brewed DK7ZD yagui for 70cm (~17dBi, 75 cm the antenna and 1,05 meters of total boom made from white PVC.
- 2m Jpole at 12 meters from the ground with 30m of Heliax LDF-4 50 Ohms cable (not picture at the moment)
- Planned is a 2m DK6ZB kind 28 ohms Yagui with 3 elements (~9 dBi) home brewed in an Arrow style with the 70cm yagui (not picture at the moment)


I use the DK7ZB yagui model to build these antennas, two benefits as I see:
  • Direct feed to the element (I know, I must put a 1:1 balun, but not toroid found yet for the task)
  • Reduced dimensions, please note the separation of reflector and 1st director to Dipole... in a normal yagui it will be maybe around twice the length. Remember this is a hand held setup.
The feed from the antenna to the 70cm radio is an 28 to 50 ohms 1/4 lambda of 2xRG-59 (75ohms) an then 1.5 meters of RG-213U

I use a PC headset with phones and mic, the mic is for the 2m Alinco and the phones for the kenwood... no picture yet...


Future improvements...


  1. Finally made the 2m yagui to mount in cross style with the 70cm yagui for make and homebrew "arrow"
  2. Improve the mechanical strength of the cables and connections... I have some ideas on mind... but I've not decided yet.
  3. Make a U shaped stand to fix the radios to it and also use the PS as the base for it... the goal is to have a PS+2m radio + 70cm radio as one unique block for transport.
73.