19-05-2017, 11:35 AM
(This post was last modified: 19-05-2017, 11:36 AM by ppppenguin.)
High IF gives better image rejection. Low IF gives more gain with older valves/transistors. It's a tradeoff. Then you choose your IF to minimise spurious effects such as 2nd harmonic beating with wanted stations.
Professional receivers often convert to a first IF above the highest frequency they can receive. Gets rid of image and other spurious problems. Also allows continous coverage of frequencies which wouldn't be possible if the IF coincided with a wanted frequency. The upconverter is sometimes followed by a 2nd conversion to a lower IF.
Professional receivers often convert to a first IF above the highest frequency they can receive. Gets rid of image and other spurious problems. Also allows continous coverage of frequencies which wouldn't be possible if the IF coincided with a wanted frequency. The upconverter is sometimes followed by a 2nd conversion to a lower IF.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
