Hi, Jo
Did you have to get the KXV3 before using it with the K3, or did you
find another way to interface the softrock to the K3?
Since the K3 roofing filters (centered at 8215) do not pass much of
your LO freq of 8204 KHz, I am guessing that you would not have seen
much effect of the moderately weak LO signal at all in the K3 - did
you try it before you added the additional isolation stage?
Jerry W4UK
At 10:04 AM 2/17/2008, jo benoit wrote:
Hello
,
While
I
was
waiting
for
my
K3
to
arrive,
I
have
been
doing
some
experiments
with
the
Softrock
Lite
.
The
softrock
lite
is
an
amazingly
good
rx
for
its
11
$.
I
was
interested
in
a
panoramic
display,
so
I
tried
it
out
on
the
TS-850
.
With
a
35.362
Mhz
Xtal
and
Rocky
software
that
was
not
much
of
a
problem.
It
worked
just
fine.
For
the
K3
,
I
ordered
a
32.812
Mhz
Xtal
.
I
read
here
that
more
isolation
is
needed
to
prevent
the
oscilator
signal
(
8.204
Mhz
in
my
case)
to
go
back
to
the
K3.
Someone
suggested
the
use
of
a
HCPL-4562
.
First
I
measured
at
the
input
of
the
Softrock,
with
the
TS-850
and
found
a
strong
S9
carrier
at
8.204
Mhz
With
the
HCPL-4562
in
front
of
the
Softrock,
I
was
able
to
hear
the
carrier
on
the
input,
but
no
indication
on
the
S-meter.
That
should
be
enough
isolation,
I
think.
Then
I
added
an
extra
stage
.
I
copied
the
schematic
from
the
K2
preamp
with
a
2N5109
to
give
the
signal
from
the
IF
an
extra
14
db
or
so
and
extra
isolation.
I
still
could
hear
the
carrier
,
somewhat
quieter,
and
see
nothing
on
the
S-meter.
The
whole
thing
is
built
into
a
metal
box
and
shielded
between
the
different
stages,
and
an
extra
shield
between
the
HCPL-4562
input
and
output.
The
connection
between
the
K3
and
the
adapter
is
a
short
coax
cable
with
two
bnc
plugs.
When
changing
from
xfil1
to
xfil2
and
xfil3
on
the
K3,
I
noticed
a
shift
in
the
display,
so
I
made
three
different
entries
in
the
rocky.ini
file:
in
the
[Band]
section
I
added
:
FL1=8625
FL2=9700
FL3=9630
I
had
to
experiment
with
these
values
until
the
signal
was
at
the
zero
mark
on
the
scale
.
One
important
thing
I
overlooked
was
the
fact
that
you
need
the
KXV3
interface.
It
was
only
when
I
was
building
the
K3
that
I
realised
that...
:)
I
have
no
special
soundcard,
I
use
the
on-board
soundcard
of
my
pc.
It
works
fine
with
Rocky,
I
haven't
tried
any
other
software
(
yet
).
73
de
on5ao
K2
# 5237
K3
# 0324
jo
benoit
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