Saturday, June 22, 2019

Es’hail 2 / QO-100


Today, construction, calibration helix antenna for contact up Link 2.4 GHz with the geostationary Amateur Radio satellite Es'hail 2 / QO-100 . 

This link can assist:

http://homepage.tudelft.nl/v0e47/demos/codes/AHelix/helix.html

Well pleased, my Helix antenna homemade have a Forward reflection = -42 dBm
Return loss = -42 dBm
VSWR = 1.016 /1
Reflection coefficient = 0.008

Unless an error on my part, I calculate the helix like this:
Dish : diameter (mm): 730 x 800
focal distance (mm): 530
F/D Ratio: 0.64
f/D x10 = turns. Offset f/D 0.6.  =  6 turns

So OK for service.. Soon ready for contacts.Preparation / setting up, up converter DX patrol 432Mhz / 2.4 GHz / PA 4 w / OCXO 10 Mhz / Circulator / bandpass filter.
Down Link 10 Ghz good reception with dish ofset 70 cm /  Modified LNB PLL twin Octagon  Green HQ / SDR RSP2 / Software SDR Play 3.09.

UPDATE: REDUCED AT 3 TURNS, WORKS FINE.


 On the bench.
Preparation / setting up, up converter DX patrol 432Mhz / 2.4 GHz / PA 4 w / OCXO 10 Mhz / Circulator / bandpass filter.
Will see...
 Updated on time ......see U. 73

later this night.. retuning a bandpass filter for QO-100
Very sharp !


26 June 2019
Boxed finished (UP converter 432 Mhz / 2.4 Ghz + Amplifier 4 w)  installed near the dish.Next step, Due to the drift of the LNB despite it is with a  PLL, (the frequency is not enough stable), I must build  a 25 Mhz TCX0 controlled by my10 Mhz GPS.
                                                                             READY....



 Problems with my Hélix.
Do not laugh! Now, during the winter, too much rain  and it disturbs the performance of my Helix antenna.
In the emergency, I installed temporarily this protection .. Now it's safe.
But. not satisfied. built a waterproof new one 
remains to put the LNB
                                                                     Ready ...
  Since 26 july 2019. All equipment are inside a waterproof box. Only 10m of 2 Coax cables to the shack for TRX Icom 910H (RG225/U)  and SDR play , (RG6/U).

See also: