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My other equipments for satellite communicaton

Since 2002 is I qrv via AO-40. My S band downconverter is manufactured by HA5BFN. I experimented also with MMDS converter.

My small equipments for AO-40

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Helix feed for 2,4 GHz

S band downconvertor and helix feed

S band helix feed with convertor on dish

S band downconverter by HA5BFN

MMDS conv. California


My small satellite ants:

4 ele Yagi for 145 MHz

9 ele Yagi for 435 MHz

1m diameter dish for 2,4 GHz

1 m diameter dish for 2,4 GHz

in my ham-shack

1m diameter dish for 2,4 GHz


1m diameter dish for 2,4 GHz


Feed for 2,4 GHz

a=29mm, b=35mm,

D=83mm, l=107mm, d=4mm

20 turn Helix

for 2,4 GHz

Helix for 2,4 GHz

with S band konvertor

Konverter for 2,4 GHz


if= 144 MHz

2,4 GHz RF source by VE2ZAZ

Doing S-band (2.4GHz) communications is often seen as technically challenging. Test equipment at microwave frequencies is hard to get and is not part of a typical ham shack. "Poor man" approaches are the best way to keep costs down and still have fun experimenting. Also, commercial equipment is usually heavy and does not offer much portability.  What made me try this solution was the need for a cheap,  portable 2.4GHz source for optimizing the position of the helix feed on my 2.4CIRCUIT DESCRIPTION
What I am suggesting here is achievable by almost anybody who owns a soldering iron. It involves the use of a computer TTL oscillator. It can be purchased at any electronics supplier chain at a price of  around 3$ (US). This type of oscillator produces a "rather square" wave, thus an output rich in harmonics.  I elected to use a 40MHz oscillator. Its output generates signals at 40, 80, 120, 160, 200...440...1200, 1240, 1280,...2320, 2360, 2400, 2440...MHz. Of course, as you go up in frequency, the amplitude of the harmonics decrease. 3GHz is probably the maximum useable frequency. GHz offset dish.

The TTL oscillator used is a leaded component. A surface mount oscillator can also be used. Connections will be done on the component pads. Also, other oscillator frequencies can be used if harmonics on different bands are desired. A +5V voltage regulator is used here to ensure that the oscillator is supplied with +5V regardless of the battery voltage. The battery or supply could ultimately go up to +35V and this circuit would still operate. Make sure you use a  decoupling capacitor at the input of the regulator, as shown on the schematic. During testing I neglected to put one and the voltage regulator operated erratically. Pick a capacitor that will sustain the input voltage. The minimum voltage that will make the source operate is around +7V.


(C) 2001 Gyetvai Zoltán OM7AQ