Yes, the I/Q signal from the KX3 goes through an analog buffer directly
into a two-channel analog to digital converter. All processing is then
done digitally by the DSP. Correcting the frequency response is a
simple matter of multiplying the frequency points by the correct number
before they are displayed. It's a good example of something that would
be complicated using analog circuitry but is trivial with a DSP.
Alan N1AL
On 04/05/2014 04:13 PM, Barry LaZar wrote:
I was hoping to get a hint from the manual as well as answer a few other
questions, But it isn't on line yet.
The I&Q data coming out of the KX3 is analog. It could be that they are,
in fact, feeding an A/D converter directly. The rest would be just some
software and a look up table. I guess I agree with you that would be the
way to go. It's straight forward.
73,
Barry
K3NDM
On 4/5/2014 7:35 PM, Walter Underwood wrote:
I bet they digitize it as early as possible, then use an FIR filter to
reshape it. Or scale the values after they FFT, since that is already
in the frequency domain. The scale values would be a vector of
constants, so it would be really fast and wouldn't even add delay (the
bane of FIR filters).
wunder
K6WRU
On Apr 5, 2014, at 6:26 PM, Barry LaZar <k3...@comcast.net> wrote:
Yep. That what I was questioning. I, too, remembered those words. I
also know it will take more than just inserting an amplifier with
inverse gain characteristics. I know it can be done. However, that
doesn't sate my curiosity as to how they did it. I just hope the
solution isn't proprietary.
73,
Barry
K3NDM
On 4/5/2014 7:14 PM, Walter Underwood wrote:
Yes. I posted the text from the manual two days ago in the KX3 list.
"The RX I/Q outputs from a receiver are not “flat” over an infinite
frequency range; the signal-conversion process results in some slope
(decrease in gain) as you move farther from the center frequency. In
the case of the KX3, the signal will be reduced by about 2.5 dB at
+/- 24 kHz, 4 dB at +/- 48 kHz, and 7 dB at +/- 96 kHz. The spectrum
amplitude on the display, including the apparent noise floor of the
receiver, will “roll off” by these amounts." (page 26)
I would not be surprised if they corrected for this in the PX3.
wunder
K6WRU
On Apr 5, 2014, at 1:55 PM, Barry LaZar <k3...@comcast.net> wrote:
Good question. I have run at 192 KHz. with the sound card I have, a
Steinberg UR22. The display I see using NaP3 shows a non-flat
response. In fact, there are some words about this in the KX3 manual.
73,
Barry
K3NDM
On 4/5/2014 1:07 PM, Uwe Hermanns wrote:
Hi,
is the frequency responce of the KX3-IQ really flat over 250 kHz?
73 de Uwe, DL4AC
---------- Weitergeleitete Nachricht ----------
Von: "Allen Patterson" <all...@cryptosafe.com>
Datum: 05.04.2014 19:03
Betreff: [Elecraft] PX3
An: "Elecraft@mailman.qth.net" <Elecraft@mailman.qth.net>
Cc:
When is the PX3 going to be available for shipping?
You mentioned several software-firmware updates for the PX3 that are
planned.
What is the general schedule for each of these updates after initial
product shipment?
When is the manual for the PX3 going to be available?
73
Allen Patterson, KC7SYR
all...@cryptosafe.com
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to uwe.dl...@gmail.com
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to k3...@comcast.net
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to wun...@wunderwood.org
--
Walter Underwood
wun...@wunderwood.org
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to k3...@comcast.net
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to wun...@wunderwood.org
--
Walter Underwood
wun...@wunderwood.org
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to k3...@comcast.net
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to n...@sonic.net
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
