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Hi Trondheim,
I expect that the most ham's are on
holiday.
I will try to explain some of your
problems.
The MF signal (0 - 22Khz or something like that)
will be mixed with a software osc to get the receiving freq. (near zero
receiver). You can change the freq. of the osc by dragging with the mouse on the
freq screen. The bandwidth can be changed with the mouse near the end of the
freq display block.
If you are using only one input signal, no
quadrature signal, the pos and neg freq are the same. You will see only the
bandwidth of half the sample freq! Using a quadrature mixer, and so two input
signals, it is possible to see the bandwidth of the sample freq.
73, PE0FKO
Fred
----- Original Message -----
Sent: Thursday, June 30, 2005 7:51
AM
Subject: [soft_radio] Re: Basic questions
... mainly resolved
Hi
all,
I have come a bit further with some help ...
1) The signal
level from the receiver was too high. When reducing
this I got the
expected signals.
2) I understand that it is normal that I have no
signal at 0 kHz but
one at -12,5 kHz and one at +12,5 kHz.
3) I
found that I could only adjust the frequency in 0,01 kHz steps
in 6 kHz
and 2 kHz frenquency span.
Even if I have not worked a lot with SDRadio
I take the liberty to
suggest few improvements:
a) Allow key entry
of frequency. E.g. enter "7,5" in the frequency
field above the spectrum
if I wanted to listen to the station -5 kHz
away from the station I am
tuned to.
b) Allow control of the frequency slider with the arrow
buttons. This
is easier when fine tuning than using the mouse.
c)
Allow key entry control of the bandwidth. When the bandwidth is
displayed
it would be nice if the band with could be controlled with
the arrows, and
maybe even entered directly.
d) Memory function to store often used
setups.
Finally - I still have too much noise. Even with the
receiver off, I
get a -60 dB peak at 0 kHz an two - 80 dB peaks at +/- 16
kHz. Is
there something wrong with my IF-signal?
73 de
OJ
Trondheim, Norway
http://www.kongsfjord.no
---
In [email protected], "oddj" <[EMAIL PROTECTED]> wrote:
> Hi
all,
>
> I just joined the group and have just connected SDRadio
0.95 to the
> 12,5 kHz IF-output from a Siemens CHR-531 receiver. What
I get is
not
> exactly what I expected ... First of all I must tune
the receiver
2,5
> kHz below the desired frequency. Second, I get 6
signals in SDRadio
> for every station, respectively +/- 3, 15 and 21
kHz offset the
> carrier. The +/- 15 kHz signal is the best.
>
> I am completely new to the SDRadio concept so I might have
overlooked
> something here? I tried to find a SDRadio FAQ or
Dummies reference,
> but had no luck.
>
> Also, how do I
fine-tune the frequency? Like for the 15 kHz offset
I
> can only
tune to 14,98 kHz ... never to 15,00 sharp.
>
> Anyone that can
help?
>
> 73 de OJ
> Trondheim, Norway
> http://www.kongsfjord.no
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