[Milsurplus] ARR 15, how to narrow selectivity???

[mac]

Cave,

I thought about trying this too.  Have acquired the filter but that's  
as far as I have progressed to date.

Dennis D.  W7QHO
Glendale, CA

On Jun 3, 2009, at 5:28 PM, David Ross wrote:

> here is a detent on the ARR-15 variable IF knob -  that detent
> actuates a switch when the variable IF knob is set to zero (i.e. when
> the variable IF frequency is 500 KCs).  That switch could be used to
> actuate a relay which switches in a 500 KC mechanical filter only when
> the variable IF knob is set to zero.
>
>  That way the variable IF tuning scheme could still be used to
> precisely set the received frequency using the main tuning knob in
> conjunction with the crystal calibrator, but the operator would have
> some real selectivity when the tuning process is complete and the
> variable IF knob is returned to it's "0" position.