Re: New K3 SN#207 built but question on AM Filter

Posted by Don Wilhelm-4 on Jan 12, 2008; 11:58pm
URL: http://elecraft.85.s1.nabble.com/New-K3-SN-207-built-but-question-on-AM-Filter-tp458592p458626.html

Paul,

Lyle answered that earlier today.  You are not doing anything wrong,
that is just the result of the bandwidth required by different
modulation techniques.

The bandwidth displayed is the *audio* bandwidth.  An AM signal requires
*twice* the audio bandwidth in the IF, so your 6 kHz IF filter is
limiting the audio bandwidth to 3 kHz.  SSB reception on the other hand
allows the audio bandwidth to be equal to the IF bandwidth, so until you
can fit the 15 kHz IF filter, you are limited to using the K3 in SSB
mode for AM stations that you wish to hear in Hi-Fidelity.

The 6 kHz filter is great for receiving amateur AM signals - which
should properly be restricted in bandwidth.

73,
Don W3FPR



Paul Webb wrote:
> Hi All
> just built my K3 up to the 10 watt level (still to fit the 100w pa) have been giving it a quick test and have a question, i have fitted the AM filter in FL2 (The FM will go in FL1) and the stock filter in FL3 (2.7KHz), i have set the filters for all modes and set FL2 (6KHz) for AM mode and also selectable in SSB Modes.
> now when i select SSB and tune to a AM signal i can alter the bandwidth to anything up to 6KHz, when i switch to AM i can only adjust the bandwidth up to 3KHz , the audio sounds like it is a 3KHz filter too, what am i doing wrong since i cant set the 6KHz bandwidth in AM.
> any ideas???
> regards
> Paul M0BMN
> K3 S/N 207
>
>  
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