Chris if you are not listening to the same frequency on both you dont want a
splitter you need a diplexer. This is effectively two filter with a common
input, one is lowpass for LF one is HP for MF (though you may also need a LP
in this side to reject BC TXs. I think there is design gen in Wes Hayward's
Intro to RF Design
You can make a minimum loss splitter .....I have used one on 136 for two
receivers but you lose about 4.5dB I think. Mine was 1.4 : 1+1 where ''1''
is a winding on a toroid with a reactance of about 250ohms. Its based on a
Racal design (Brian CT1DRP used to work for them) the 1+1 can be centre
tapped to ground.
Alan
G3NYK
----- Original Message -----
From: "Chris Wilson" <[email protected]>
To: <[email protected]>
Cc: <[email protected]>
Sent: Tuesday, March 13, 2018 10:20 PM
Subject: LF: Antenna splitter question
Hello LF 'ers,
I am trying out a Red Pitaya on LF RX. It's running the open source
HPSDR software which I have never really liked or got to grips with.
With huge respect to the writers it always seems like it now needs a
ground up re write as it has grown beyond its user interface IMHO, and
is far from intuitive to use. However, I may be stuck with it as the
firmware for running HDSDR which I am fully comfortable with and which
has been my go to software for SDR for many years, has not worked for
me with the Red Pitaya, although I haven't quite given up yet.
HPSDR allows 2 receivers in effect, but having the one aerial means I
will probably have to use a splitter. I would like to RX on LF and MF
at the same time. I haven't seen a commercially made one that goes low
enough, has anyone got a link to a DIY one please? Thanks.
I am running the Red Pitaya for the first tie tonight, I had to add a
pre amp in front of it as it seemed a bit deaf on LF, I will be very
curious to see how it works. Listening for WSPR2 and WSPR15.
--
Best regards,
Chris mailto:[email protected]
|
