[JRC] NRD545 OWNERS

[Chris Smolinski]

Steve J. Walker wrote:
> Depends on what you use the radio for, the AM audio bandwidth is limited
> already, this mod reduces it more - and takes a chunk out of NFM too.
> 
> BUT on a crowded SW BCB band its great, no more filter skirt blow by, as
> the 545 has about 45db rejection at this DSP stage for an IF its really
> crap (the R8 and R75 are way better), the new filter helps a lot to
> avoid the odd effects you hear when stations are within its 10-15Khz
> pass band.

I have't heard too many odd effects. One that I have heard several times
is that the radio seems to get "locked" into some sort of state when you
tune past a strong station, it is hard to describe, but the audio is
then distorted. Changing modes (from AM to USB and back for example)
will fix it. The joys of DSP I guess. 
 
> Worth trying one with it - or hear an audio sample but I only really do
> UTE stuff and its great, the audio quality is not the thing I got the
> radio for.

Well... I do both UTE monitoring and SWListening. My older receiver is
an R71A, which of course has an excellent front end, although extremely
poor audio. Has anyone come up with a scheme for installing both
filters, perhaps some sort of small PCB, with the ability to switch in
either filter? I'm not sure if diode switching would be acceptable in
this case?
 
> DaveZ has some comments about it on this www page, along with some DSP
> comments that might help you on the purchase of the filter.

Chris