R: [amsat-bb] Weak Signal Banquet NF numbers

["i8cvs" <domenico.i8cvs@xxxxxx>]

Hi  Mike

There are mixers that use a suitable phase relationship (similar principle
to phase SSB )or use a high Q of the mixer circuit (similar to filter SSB)
to suppress the unwanted  image band  or at list attenuate it to a great
degree.
Using  your  Anaren image reject mixer is like to add a passband filter in
front to a regular DBM mixer to remove from its input the power of noise
coming to it from the image band.
The advantage to remove the image noise from the input of  a mixer has been
already discussed in this round table.

73 de i8CVS Domenico



----- Original Message -----
From: Mike Kana <cosmo224@execpc.com>
To: <amsat-bb@AMSAT.Org>
Sent: Saturday, May 26, 2001 5:55 AM
Subject: [amsat-bb] Weak Signal Banquet NF numbers


> Greetings all
>
> This talk about noise figure and mixers brings up a question about a
> surplus
> mixer that I have been saving for a project.  It is an Anaren image
> reject
> mixer for the 2-4ghz band.  I looked the part number on the Anaren page
> and found that it has an IF frequency centered around 50 to 70 mhz.
> The mixer has an sma input for RF, LO, and an IF1 and IF2 output.  I
> would
> suspect I would terminate one of the ports for use.  Judging from the IF
>
> range, the LO must be right near the RF frequency - 2400mhz would have
> a 2350 LO for a 6m IF.  Question - what advantage does this mixer have
> over a regular
> DBM - would the image rejection make the mixer as good as a DBM with
> a filter in front of it?  Any general info would be appreciated.
>
> tnx es 73
> Mike   AA9IL
>
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