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
Acrobat Reader (pdf) format -
348 kB Slovak language
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
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My small satellite ants:
4 ele
Yagi for 145 MHz
9 ele
Yagi for 435 MHz
1m
diameter dish for 2,4 GHz
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1 m diameter dish for
2,4 GHz
in my
ham-shack
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1m diameter dish for 2,4
GHz
Feed
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1m diameter dish for 2,4
GHz
Feed
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Feed for 2,4 GHz
a=29mm,
b=35mm,
D=83mm,
l=107mm, d=4mm
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20 turn Helix
for 2,4
GHz
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Helix for 2,4 GHz
with S
band konvertor
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Konverter for 2,4 GHz
by
HA5BFN
if= 144
MHz
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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.
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