[R-390] Notch filter

[bw]

> Hi all,
> 
> Is there any one add on that I can get to produce a notch
> filter function for my R-390A.  I don't want to modify the
> receiver.  I have the QF-1A unit, but it's kinda of old and
> I don't trust it.
> 
> Thanks
> 
> Chuck


The Heath HD-11 works very well as either a notch or a Q multiplier. Best of
all, it is tube gear using the 12AX7. I've had mine hooked up for a year
now. They are fairly cheap.



Barry