[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: choice of IF frequencies



Oops! sorry, I meant the 3x0 mixer spur (3x input frequency leaking out
the mixer output).


laura halliday wrote:
> 
> John Stephensen, KD6OZH <kd6ozh@gte.net> wrote:
> 
> >Yes, it can be done and most of the 1296 MHz transverters
> >in the 1960's and 1970's used a 28 MHz IF. However, they
> >all used fairly large narrowband interdigital filters built
> >up from sheet metal and tubing. This was required to get a
> >Q high enough to reject LO and image frequencies...
> 
> There is of course nothing preventing you from building
> an image-reject mixer, in which case you can use any IF
> you want. Even baseband. All you need is enough image
> rejection to keep the image from killing the noise
> figure. If you can't be bothered, you can also just
> eat the noise figure hit. Based on what I've heard from
> AO-40 so far, this won't be much of a problem...
> 
> Laura Halliday VE7LDH     "Que les nuages soient notre
> Grid: CN89mg               pied a terre..."
>                                    - Hospital/Shafte
> _____________________________________________________________________________________
> Get more from the Web.  FREE MSN Explorer download : http://explorer.msn.com
> 
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home