[HBR] Cascading IFs for better skirt selectivity?

[Peter Bertini]

On Mon, Aug 18, 2008 at 1:46 PM, Ian Wilson <ianmwilson73 at gmail.com> wrote:
> If you are going to use two of the 85kc IFTs then I would think that
> you could produce both good skirt selectivity and a flattish pasband
> by setting one of the transformers for "overcoupled" and one of them
> for "nornal" (the position of the coupling rod sets this).
>
> The simplest way to couple the IFTs is probably just to use a
> tube. You can arrange for the gain to be low (or just include it in
> an AGC chain if there is one in your design).
>
> 73, ian K3IMW

Ha, ha, you got me there Ian, obviously a tube would do the job. That was
too easy :)  But I'd like to use passive coupling, and incorporate the
T-Notch at
that point as well. I suppose that is something that will need some
breadboarding
and evaluation to determine what works and what doesn't?

 Regarding passband, I was thinking of sweeping the
IF and watching the passband on my scope to see exactly what effect
stagger tuning
and playing with the coupling would have on improving the shape factor of the
passband.

BTW, I noticed W7QKR's ticket showing as being past renewal on QRZ.com.
I hope that isn't a bad omen. I like some of the mods he did to the RX in
the past.

Pete