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Re: Popularity of 2m I.F.



Today I decided that I don't want to mess with a 2 meter IF if possible. I
am tired of having to switch converters and radios on the 2 meter side.
There is also the risk of keying the radio while trying to work 2 meters on
another satellite. To solve this situation at my house I am going to use a
50 MHz IF since I do not operate 50 MHz too much.

Here is what I plan to do tonight:

All of my 2401 down converters use a 94 MHz crystal that is multiplied by 24
to produce 2256 MHz for the LO.

This gives you 2401 - 2256 = 145 MHz

Now, if you take some of the original 94 MHz signal and pass it through a
mmic to get 7dBm or 13 dBm of signal at 94 MHz and feed it into a mixer, you
can mix the 145 MHz IF down to 51 MHz which falls right on the 6 meter band.
The image rejection is not hard to achieve this way.

This gives you 2401 - 2256 = 145 - 94 = 51 MHz

The only problem that I see with this approach is that if you transmit on 2
meteres you might interfere with the downconverter some. You  can at least
transmit on 2 meters and not blow anything up.

PIeter Ibelings
N4IP




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