[Elecraft] K3 FM filter required for full AM receive width

[Jerry Flanders]

Sounds good for SWL. Only downside (a minor one, IMO) is that you 
might get response from images 30 KHz away. How much weaker is a 
signal when you tune to its image 30 KHz up/down?

Jerry W4UK

At 11:01 AM 5/5/2008, Dave Martin wrote:
>On 5/5/08, Stewart Baker <stewart at baker.nildram.co.uk> wrote:
> > Why not an LC filter for AM reception instead of an expensive
> >  crystal roofing filter ?
> >
>That's what I did.  I cut a scrap of PC board to the size of a filter
>and used three toroids with tuning and coupling caps.  It worked just
>fine in position one, set up as 13 KHz.  The DSP hasn't suffered at
>all.  Maybe with more antenna gain one might see some overload from
>nearby signals, but not with my modest wire.  I sure wouldn't transmit
>with it, though.  It's hugely wide, offering no attenuation of
>unwanted mixer products.
>
>Dave  W5DHM
>_______________________________________________