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Author Topic: 2.4 GHz or 2401 MHz?  (Read 4472 times)

W0FM

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2.4 GHz or 2401 MHz?
« on: September 16, 2002, 12:51:44 PM »

I am a bit confused.  (But nothing new there!).

I have recently completed building the WDG-040 2.4 GHz downconverter with a 144 mHz IF for AO-40 reception on my FT-847.  The manual says that the converter outputs to 144 mHz, but does not say precisely what input frequency outputs to 144 mHz.

In other words, does this mean that 2.4 GHz (even) would come down at 144 mHz and 2401 mHz would output to 145 mHz or would it be more likely that 2401 mHz (the actual satellite TX freqency band) would come down to 144 mHz on my receiver.

Thanks,

Terry, WØFM
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K0HZI

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2.4 GHz or 2401 MHz?
« Reply #1 on: September 19, 2002, 08:14:02 PM »

Check the AMSAT site, lot of info on Satellite and AO-40 FAQ.  http://www.amsat.org/
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K9PO

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2.4 GHz or 2401 MHz?
« Reply #2 on: October 01, 2002, 01:51:51 PM »

Not familiar exactly with the kit you are building but a downconverter mixes the RX Freq. to IF. Depending on what your LO is will determine your IF. The basic equation is RF plus or minus (depends on the filter but I am sure you are using the minus in this case) the LO = IF. If you can determine what your LO frequency is then it is pretty easy to get into the ballpark on what your IF will be.

For instance if you had a to have 144MHz IF at an input freq of 2401MHz you LO is going to be 2257MHz.

Last way to figure it out is use a know RX frequecy and move your IF radio until get an output and that will tell you your conversion factor

73
Scott
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K7KCS

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2.4 GHz or 2401 MHz?
« Reply #3 on: December 06, 2002, 02:13:51 PM »

Take the information litterally:

2.400 Ghz equals 144 Mhz
then by extrapolation . . .
2.401 Ghz equals 145 Mhz
2.402 Ghz equals 146 Mhz
2.403 Ghz equals 147 Mhz and
2.404 Ghz equals 148 Mhs
which probably the limit of the downconverter

At least this is the way the Down East unit I bopught works.

Tracy K7KCS
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