To provide correct
orientation my PCB artwork has a mark to indicate
the front (fascia) side of the radio.
is the small indent in the circle.
Note too that I have used 5 pin sockets , which are
a little more common to find , but if you can find 4
pin ones it is better.
In operation the filter
does as expected , it does offer wide band reception
on AM mode.
audio quality is very nice , especially on strong
signals where you can really appreciate the sound
with minimal noise.
the filter is VERY wide ..... !!!!!!!!!!!!!!
filter is being used the radio is quite useless at
digging out of hard
to hear signals that are alongside strong signals
.... but then ,
perhaps you would not be using the wide filter in
this situation anyway
effect that the wide bandwidth gives is like this...
the ear it
sounds like the frequency pulling that you can get
with FM signals on
the crowded FM BCB , but of course it is not the
is happening here is when you are listening to a
station and its signal strength drops away the AGC
any other signal that is heard within the wide
filters response becomes louder , even if this
station is off frequency.
So it sounds as if the radio has tuned away , but it
really the only negative aspect to this 'wide as a
barn door' LC filter.
earlier it is no comparison to a real X-tal filter ,
but for the cost
of say $5 , it is pretty hard to beat , and quite
usable as it is.....
As usual , use of these files is free to all Hams ,
but use by anyone , in any way to make profit is