Man, this is an active email group, but thats good, I got lots to read and
very interesting,
Ken brought up the question of whether you can notch
the I and Q signals in the audio chain of a receiver?
I have had receivers with i.f. notch before and as far
as I understand the two phase
Art:
The expansion slot idea is good. I saw a receiver like that somewheres on
the net.
Dan
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Must have a bad fan, I can hardly hear mine, it's so quiet.
At 09:17 PM 4/3/2006, Robert McGwier wrote:
Today I installed a dual PPC Mac in my SDR lab at work. GnuRadio and
DttSP and WSJT are all on the agenda. I helped get Portaudio going for
GnuRadio and DttSP. PortAudio is a Portable Audio
I'm wondering what the insertion of notch filters into the IQ channels
will do to the quadrature relationship of those channels.
While I'm sure the insertion of the notch filters will suppress certain
narrowband frequencies effectively I think it would be most difficult to
maintain a quadrature
Hi Dan,
It's the obvious progression as the softrock and similar technology
receivers become more sophisticated and as the quadrature
transmitters become available. Since the computing power is available
inside the same box, putting the transceiver there also is a good
thing. Another user
You would not like the Quadrature clock to be at the frequency of
interest, but you would want it about 10KHz to 15KHz away, the LO is
often picked up along with 60Hz hum giving you a huge spike at the
center of the pass-band.
If you Quadrature clock is at 443KHz or 467KHz instead then your
So where can one get the source so one could modify it?
At 11:08 AM 4/4/2006, you wrote:
--- In soft_radio@yahoogroups.com, [EMAIL PROTECTED] [EMAIL PROTECTED]
wrote:
[snip]
Ken brought up the question of whether you can notch
the I and Q signals in the audio chain of a receiver?
I
Dan,
I built a homebrew board to plug into my RA6830 that converts 455 KHz to
7.625 KHz using a color burst crystal divided by 8. My converter is a double
balanced tayloe and oscillator is a soft rock 40 copy. I put a 6 dB pad at the
input so the input Z is forced to 50 ohms. It would be very
--- In soft_radio@yahoogroups.com, KD5NWA [EMAIL PROTECTED] wrote:
So where can one get the source so one could modify it?
Cecil Bayona
KD5NWA
www.qrpradio.com
Cecil,
I have already sent out the source code of SDRadio many times to
those who requested it. If you want it, I can send it
--- In soft_radio@yahoogroups.com, KD5NWA [EMAIL PROTECTED] wrote:
I and Q signals depend on their phase relationship in order for it to
work correctly, something like a notch filter will mess up that
relationship and render them useless. Besides the main point of a QSD
receiver is for the
Art:
I have one receiver here a Philco Ford Sierra 128 A which has every single
circuit board in a sheilded box, even the audio board and its the best receive
I have. I do not get noise with it when I use it with the PC.
So receiver shielding is certainly a plus on any design that might
Ray:
I am certain that there may be some trade off with the notch filter idea. If
the circuit responce is good to 50 KHz which is not hard to achieve in audio
circuits then the sinewave accuaracy and phase may be preserved. Of course
this is theory until it has been checked out on the test
Wolfgang:
Yes, I think you would have to have pll control for DRM and I read that they
do not recommend AGC on during DRM? So thats what I meant earlier when I was
writing about turning AGC off.
Dan
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Call Anyone,
KD5NWA:
Yes Rick Campbell explained that the isolation of the vfo or local oscillator
is criticle when operating the circuit on the fundamental in the mixer scheme.
And offset of the frequency is desirable to offset the center frequency when
needed
If one wanted too, they can use a panel
No Dan!
This is just so wrong. You cannot compare what can be done via DSP to
what you will ever achieve in hardware.
[EMAIL PROTECTED] wrote:
Ray:
I am certain that there may be some trade off with the notch filter idea.
If the circuit responce is good to 50 KHz which is not hard to
In the PowerSDR/SDR-1000 software there is a block LMS automatic notch
filter that I should have enhanced with a manual notch a long time ago
for CW in particular. That said, this operates on complex signals and
produces a complex signal. It does not hurt the image and is the single
most
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