[amsat-bb] Be kind to our old lady AO-7

[John Geiger]

Thanks for the information, that clears up one question I have always had.

73 John AF5CC

On Wed, May 31, 2017 at 9:41 PM, JoAnne Maenpaa <k9jkm at comcast.net> wrote:

> Hi John,
>
> It's a bit involved without having a white board or the use of hands to
> wave
> around but maybe I can state the principle in 25 words or less ...
>
> A transponder is pretty much an RF mixer where a local oscillator (LO)
> frequency is mixed with an input signal. The resulting output of the mixer
> is a combination of ...
> 1. the LO frequency (call it F1)
> 2. the originating input frequency (call it F2)
> 3. a resultant output of LO-input freq  (F1-F2)
> 4. a resultant output of LO+input freq  (F1+F2)
>
> Depending on which resultant mixer output you transmit you'll be inverted
> or
> not inverted. Perhaps that is too simple of an explanation to make sense.
> More details thanks to google like this one:
> http://www.radio-electronics.com/info/rf-technology-design/
> mixers/rf-mixers-
> mixing-basics-tutorial.php
>
> More experts around here will tell better :-)
>
> --
> 73 de JoAnne K9JKM
> k9jkm at amsat.org
>
>
>
>