Don Wilhelm-4 wrote:
I have been following this discussion with casual interest, and I
observe that we have come full circle once again with receiver front
ends.
[snip]
I wonder what is next - It seems to me that we reach a practical limit
for front end sensitivity when a
In a recent message, Julian, G4ILO [EMAIL PROTECTED] wrote ...
I don't really care what goes on inside the box but I want my radio in a box
marked radio with its own independent controls, that works separately from
any computer.
I do concur with that, Julian, which is why I have not gone for
Hello Julian,
Technology is wonderful, but I still have an extreme reluctance to adopt any
kind of SDR that is based on general purpose computers...
The one of the interesting things about using personal computers for SDR
is imho that generally more people can take part in their development
Toby Deinhardt wrote:
I've got a hankering to unite a panadapter with
information from the WinTest band map, DX-cluster spots and maybe a few
other goodies. No idea when and if I'll actually do this, but with this
kind of an open system I (much more easily) can if I want.
This is
Hi Larry,
I have lots of experience with video editing suites, both traditional, and
high end workstation based systems. They each have their advantages, and I
haven't noticed any speed advantage for either when it comes to
post-production. When it comes to live production, however, buttons and
Yes, it has been an informative thread indeed. I considered weighing in,
but everything seemed to be covered in excellent detail. I will say
that, based on my measurements, a much bigger issue today is transmitter
performance rather than receiver performance. The main culprit is of
course
The one of the interesting things about using personal computers for SDR
is
imho that generally more people can take part in their development in
major
or minor ways. This is why I just recently decided to purchase the QS1R
I can understand the attraction of that for hams, just as I
Julian, G4ILO wrote:
a dedicated and focussed team, as in the case of Microsoft.
That should have been as in the case of Elecraft!
-
Julian, G4ILO. K2 #392 K3 #222.
http://www.g4ilo.com/ G4ILO's Shack http://www.ham-directory.com/ Ham
Directoryhttp://www.g4ilo.com/kcomm.html
Nico, this is truly exceptional phase noise performance! My sincerest
congratulations to you. Have you described how you achieved this somewhere?
73, Bill W4ZV
Nico Palermo, IV3NWV wrote:
Bill,
the phase noise of Perseus is as follow:
Offset (kHz) 25 1020 50
On Thu, Dec 4, 2008 at 1:54 PM, Julian, G4ILO [EMAIL PROTECTED] wrote:
The one of the interesting things about using personal computers for SDR
is
imho that generally more people can take part in their development in
major
or minor ways. This is why I just recently decided to purchase the
On Thu, Dec 4, 2008 at 2:23 PM, Bill W4ZV [EMAIL PROTECTED] wrote:
Nico, this is truly exceptional phase noise performance! My sincerest
congratulations to you. Have you described how you achieved this somewhere?
73, Bill W4ZV
Not to speak for Nico, but direct sampling SDRs use a
On Thu, Dec 4, 2008 at 1:54 PM, Julian, G4ILO [EMAIL PROTECTED] wrote:
I was really more concerned with what support there will be for the current
generation of SDR radios in, say 10 years time. If the PC that runs the
current software dies, and you can't get a new PC that runs XP (or whatever
Phil and Chen,
Thanks! I thought it looked like crystal filter performance but was
thinking it was synthesized. This looks like a much better system
than Flex's QSD. I wonder how long it will be before Flex goes to the
same system? Phase noise and BDR have been Flex's weak links IMHO.
I just
On Dec 4, 2008, at 1:06 PM, Bill Tippett wrote:
This looks like a much better system than Flex's QSD.
For single signal use, I agree completely Bill. By the time you've
matched the sampling rate of a direct SDR to a signal with 500 Hz
bandwidth, you have adequate dynamic range. (And not
Can we end this thread? It seems to have drifted away from Elecraft. I, and I
believe others too, could care less about all these numbers and the discussions
surrounding them.
Dave N8AG
___
Elecraft mailing list
Post to:
: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Kok Chen
Sent: Thursday, December 04, 2008 5:21 PM
To: Elecraft Reflector
Subject: Re: [Elecraft] K3 ADAT ADT-200A by HB9CBU
On Dec 4, 2008, at 1:06 PM, Bill Tippett wrote:
This looks like a much better system than Flex's QSD
On Wed, Dec 3, 2008 at 12:55 AM, Joe Subich, W4TV
[EMAIL PROTECTED] wrote:
. You are making the incorrect assumption that we have no
control over the upper or lower limits. If band or sky noise
is the limiting factor on the low end, then adding
attenuation in front of the ADC to adjust for
Hi John,
In this part of Scotland (approx 56N 3W), the carrier levels of many of the
BC stations at 7100 kHz and above get up to +5dbm / +10dbm if propagation is
normal. These are measured levels at the shack end of a coax feeder with
my backup 40m dipole at 70ft selected and in use. It is
I have been following this discussion with casual interest, and I
observe that we have come full circle once again with receiver front ends.
In the beginning we had 'receivers' that could hear much of the RF
specturm - a detector connected to an antenna, later selectivity was
used ahead of
This is a fascinating, informative discussion. Thank you to the
principals for keeping it by-and-large on a super-high plane. Unfortunately
I am not versed in the technologies being explored, and would really
appreciate - after the issues are fully discussed, don't need a
blow-by-blow - a
On Wed, Dec 3, 2008 at 6:22 AM, Philip Covington [EMAIL PROTECTED] wrote:
On Wed, Dec 3, 2008 at 12:55 AM, Joe Subich, W4TV
I do not believe that any wideband SDR can cope with the
instantaneous peaks greater than the ADC rail in the
limiting condition (a large number of extremely strong,
:[EMAIL PROTECTED] On Behalf Of Philip
Covington
Sent: Tuesday, December 02, 2008 6:12 AM
To: [EMAIL PROTECTED]
Cc: elecraft@mailman.qth.net; Bill W4ZV
Subject: Re: [Elecraft] K3 ADAT ADT-200A by HB9CBU
On Mon, Dec 1, 2008 at 8:38 PM, Joe Subich, W4TV
[EMAIL PROTECTED] wrote
John
Can't help you with numbers, just the experience of friends in that
situation, ie they can operate with special receivers having special mixers,
often home brew, whereas it is impossible without.
David
G3UNA
David Cutter wrote:
Some folk suffer extremely strong QRM from broadcasters
On Mon, Dec 1, 2008 at 8:38 PM, Joe Subich, W4TV [EMAIL PROTECTED] wrote:
Of course, but there is still a finite range between the
two limits. The maximum instantaneous peak is driven by
the number and strength of incoming signals and the minimum
discernable signal level is defined not by
On Mon, Dec 1, 2008 at 4:48 PM, Kok Chen [EMAIL PROTECTED] wrote:
On Monday, December 01, 2008, at 01:16PM, Bill W4ZV [EMAIL PROTECTED]
wrote:
...which is why the hybrid approach of a narrow roofing filter before the
ADC works so well in Orion and the K3.
Bill is correct.
Think of this
On Mon, Dec 1, 2008 at 9:02 PM, Bill W4ZV [EMAIL PROTECTED] wrote:
Joe Subich, W4TV-3 wrote:
Processing
gain may be of value at microwave frequencies with a quiet
sky but it is not going to help below 10 MHz with extreme
signals and high noise levels.
Joe, as near as I can tell, you've
Its dynamic range may be OK for IMD but today's SDRs cannot approach the BDR
of
rigs like the K3 until even higher resolution ADCs become available.
Sorry to tell you a bad new: you are wrong!
Nico Phil,
When can we expect to see direct R.F.-sampled SDRs with better MDS performance?
Nico Palermo, IV3NWV wrote:
You are not replying my question, Bill.
I've simply asked if you are able to listen to a -105 dBm with a + 7 dBm
inteferer placed at
a 2 kHz offset with your receiver.
You have two choices:
1) No, I can't.
2) Yes. I can.
If the reply is #1 you should explain me why
On Tue, Dec 2, 2008 at 6:37 AM, Philip Covington [EMAIL PROTECTED] wrote:
The difference is that while W8JI may be an expert in many other
(analog) areas, his disparaging comments made on various mailing lists
shows an ignorance in the SDR realm (except maybe for a bad experience
with a
On Tue, Dec 2, 2008 at 6:49 AM, Paul Christensen [EMAIL PROTECTED] wrote:
Its dynamic range may be OK for IMD but today's SDRs cannot approach the
BDR of
rigs like the K3 until even higher resolution ADCs become available.
Sorry to tell you a bad new: you are wrong!
Nico Phil,
When can we
Hi Phil,
There is no inherent reason why the MDS could not be that low in
direct sampling SDRs. It is mainly a matter of design
decision/implementation.
This may be a stupid (or at least ignorant) question, but if the dynamic
range of the ADC itself is defined by the number of bits it
Philip Covington wrote:
problem of the phase noise of the LO. Even QSD based SDRs which use
a DDS for the LO have worse phase noise (and spurs) than the crystal
oscillator LO in direct sampling receivers like the Perseus or QS1R.
It seems to me that high speed A/D conversion is much more
On Tue, Dec 2, 2008 at 8:05 AM, David Woolley (E.L)
[EMAIL PROTECTED] wrote:
Philip Covington wrote:
problem of the phase noise of the LO. Even QSD based SDRs which use
a DDS for the LO have worse phase noise (and spurs) than the crystal
oscillator LO in direct sampling receivers like the
Philip Covington wrote:
On Tue, Dec 2, 2008 at 8:05 AM, David Woolley (E.L)
It may seem that way to you, but in real life it turns out the the DDS
generates spurs due to only approximating a sin function, clock
leakage, number of bits, etc... There is not the same issue in the
There is no
Bill,
the phase noise of Perseus is as follow:
Offset (kHz) 25 1020 50
Phase Noise (dBc/Hz) -141 -145 -148 -151 -155
As a picture is worth one thousand words, see here for more:
http://microtelecom.it/perseus/tests/Perseus-phasenoise.jpg
To make the test, the phase
On Tue, Dec 2, 2008 at 10:27 AM, David Woolley (E.L)
[EMAIL PROTECTED] wrote:
Philip Covington wrote:
On Tue, Dec 2, 2008 at 8:05 AM, David Woolley (E.L)
It may seem that way to you, but in real life it turns out the the DDS
generates spurs due to only approximating a sin function, clock
Nico Palermo wrote:
You probably are unaware that an ADC dynamic range in a given bandwidth
does not depend just on its ENOB (effective number of bits) but also on
the sampling frequency.
Surely, in terms of the interfering signal, that bandwidth is something
like 30MHz, rather than the
Rig 1kHz2 10 20 50 100 1M
K3 -110 -119 -136 -140 -143 -144 -150
IC7800 -103 -112 -130 -138 -140 -140 -140
FT2000 -102 -105 -128 -129 -128 -128 -128
ORION 2 -121 -129 -126 -125 -118 -128 -138
OMNI 7 -102 -103 -120 -123 -127 -129 -126
F5000 -123 (same at all
Hi Guy's
Thanks for the interesting discussion on the state of the art in SDR
technology. This discussion does raise a few questions in my mind that I
would like to ask. To me it is a question of the theoretical as opposed
to the practical. Does it really matter if a receiver can hold up to a
John KD8K wrote:
. This discussion does raise a few questions in my mind that I
would like to ask. To me it is a question of the theoretical as opposed
to the practical. Does it really matter if a receiver can hold up to a
80db over 9 signal 2 KHz away or is this just a theoretical exercise?
in to their
own.
David
G3UNA
- Original Message -
From: Ron D'Eau Claire [EMAIL PROTECTED]
To: elecraft@mailman.qth.net
Sent: Tuesday, December 02, 2008 10:14 PM
Subject: RE: [Elecraft] K3 ADAT ADT-200A by HB9CBU
John KD8K wrote:
. This discussion does raise a few questions in my mind
David Cutter wrote:
Some folk suffer extremely strong QRM from broadcasters on 40m
(particularly on the east coast of Scotland) and to them there is a
real desire for the best possible gear to hear weak stations amongst
huge bc signals from Europe. That's where receivers like the Perseus
, 2008 6:11 PM
Subject: Re: [Elecraft] K3 ADAT ADT-200A by HB9CBU
David Cutter wrote:
Some folk suffer extremely strong QRM from broadcasters on 40m
(particularly on the east coast of Scotland) and to them there
is a
real desire for the best possible gear to hear weak stations
amongst
huge
Hi,
has anybody done a serious test of the ADT-200A transceiver yet?
http://www.adat.ch/index_e.html
http://www.adat.ch/pub/Presentation_Hamfest_22-09-07.pdf
http://www.adat.ch/pub/ADT-200A_Messresultate_V10.pdf
It would be rather interesting to see how the concept used by the K3 (24
bit
Hi,
I, too, would be very interested in seeing how entire HF spectrum digitized
at once receivers would fare in the real world. I am *very* skeptical.
Although the Perseus (with that architecture) receiver fares relatively well
in the recent ARRL test, the testing completely ignores what happens
AB2TC wrote:
Hi,
I, too, would be very interested in seeing how entire HF spectrum digitized
at once receivers would fare in the real world. I am *very* skeptical.
Although the Perseus (with that architecture) receiver fares relatively well
in the recent ARRL test, the testing completely ignores
On Mon, 2008-12-01 at 06:35, ab2tc wrote:
Hi,
I, too, would be very interested in seeing how entire HF spectrum digitized
at once receivers would fare in the real world. I am *very* skeptical.
Although the Perseus (with that architecture) receiver fares relatively well
in the recent ARRL
Philip Covington wrote on Monday, December 01, 2008 at 3:13 PM
The Perseus actually out performs the K3 receiver regardless of what
the recent ARRL test reports. I agree that the ARRL needs to come up
with valid tests to evaluate real world performance of digital
receivers such as the Perseus,
Alan Bloom wrote:
On Mon, 2008-12-01 at 06:35, ab2tc wrote:
Hi,
I, too, would be very interested in seeing how entire HF spectrum
digitized
at once receivers would fare in the real world. I am *very* skeptical.
Although the Perseus (with that architecture) receiver fares relatively
On Mon, Dec 1, 2008 at 1:29 PM, Bill W4ZV [EMAIL PROTECTED] wrote:
Alan Bloom wrote:
On Mon, 2008-12-01 at 06:35, ab2tc wrote:
Hi,
I, too, would be very interested in seeing how entire HF spectrum
digitized
at once receivers would fare in the real world. I am *very* skeptical.
Although
PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Philip
Covington
Sent: Monday, December 01, 2008 3:21 PM
To: Bill W4ZV
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 ADAT ADT-200A by HB9CBU
On Mon, Dec 1, 2008 at 1:29 PM, Bill W4ZV
[EMAIL PROTECTED] wrote:
Alan Bloom wrote
Joe Subich, W4TV-3 wrote:
This is not correct. You can't just compare the number of
bits without taking into consideration the ADC sampling rate
and signal bandwidth. Please see the concept of signal
processing gain or process gain.
The concept of processing gain is completely
On Mon, Dec 1, 2008 at 3:56 PM, Joe Subich, W4TV [EMAIL PROTECTED] wrote:
This is not correct. You can't just compare the number of
bits without taking into consideration the ADC sampling rate
and signal bandwidth. Please see the concept of signal
processing gain or process gain.
The
On Monday, December 01, 2008, at 01:16PM, Bill W4ZV [EMAIL PROTECTED] wrote:
...which is why the hybrid approach of a narrow roofing filter before the
ADC works so well in Orion and the K3.
Bill is correct.
Think of this this way: the clipping level of a codec does not change, but the
On Mon, Dec 1, 2008 at 4:16 PM, Bill W4ZV [EMAIL PROTECTED] wrote:
Joe Subich, W4TV-3 wrote:
This is not correct. You can't just compare the number of
bits without taking into consideration the ADC sampling rate
and signal bandwidth. Please see the concept of signal
processing gain or
Forward on behalf of Leif SM5BSZ:
___
Hi All,
I am not a member on the Elecraft list, but I did work quite some
time on this issue:
I, too, would be very interested in seeing how entire HF spectrum digitized
at once receivers would fare in the real world. I am
On Mon, Dec 1, 2008 at 1:29 PM, Bill W4ZV [EMAIL PROTECTED] wrote:
73, Bill W4ZV
P.S. How many hits for 1000 or 5000 in the contest soapbox so far?
ZERO. (Which says something about SDRs in use by real contesters).
Not from the contest soapbox, but...
GI4NKB Awarded First Place for
Isn't the K3 an SDR???
GM4FDM
Philip Covington wrote:
On Mon, Dec 1, 2008 at 1:29 PM, Bill W4ZV [EMAIL PROTECTED] wrote:
73, Bill W4ZV
P.S. How many hits for 1000 or 5000 in the contest soapbox so far?
ZERO. (Which says something about SDRs in use by real contesters).
Philip Covington wrote:
On Mon, Dec 1, 2008 at 1:29 PM, Bill W4ZV [EMAIL PROTECTED] wrote:
73, Bill W4ZV
P.S. How many hits for 1000 or 5000 in the contest soapbox so far?
ZERO. (Which says something about SDRs in use by real contesters).
Not from the contest soapbox, but...
Hi,
Also note that the Flex5000 does not have the digitize the entire HF band
at once architecture but rather uses a I/Q direct conversion approach
followed by a pair of audio A/D converters sampling at 192kHz. The OP and my
follow-up question was really on how well the convert all of it at once
Tom Wylie wrote:
Isn't the K3 an SDR???
GM4FDM
Not according to Flex Systems...Real radios don't need knobs.
Maybe not, but so far they don't win HF contests either...unless there are
no other entrants in the category. ;-)
Technically you're correct. The K3 and most high-end
Bill W4ZV wrote:
Correct. I believe the Perseus only has a 14-bit ADC so it's more limited
in dynamic range than the 24-bit ADCs commonly used by other SDR rigs.
You probably are unaware that an ADC dynamic range in a given bandwidth
does not depend just on its ENOB (effective number of bits)
Nico Palermo, IV3NWV wrote:
If we follow the definition of BDR as made by ARRL tests you are right.
Unfortunately this definition does not give an exact idea of the true
dynamic
range of a receiver.
I can demonstrate, and I think that Phil can do it as well with his QS1R,
that if you
Covington
Sent: Monday, December 01, 2008 4:40 PM
To: [EMAIL PROTECTED]
Cc: elecraft@mailman.qth.net; Bill W4ZV
Subject: Re: [Elecraft] K3 ADAT ADT-200A by HB9CBU
On Mon, Dec 1, 2008 at 3:56 PM, Joe Subich, W4TV
[EMAIL PROTECTED] wrote:
This is not correct. You can't just compare
has anybody done a serious test of the ADT-200A transceiver yet?
When I asked this question, I sure did not expect the very educational
discussion which has broken out. I'm very thankful, as a photographer
who programs graphic systems for television, many good points were made
which I might
Joe Subich, W4TV-3 wrote:
Processing
gain may be of value at microwave frequencies with a quiet
sky but it is not going to help below 10 MHz with extreme
signals and high noise levels.
Joe, as near as I can tell, you've hit on the primary cause of arguments
between intelligent folks
In that case the BDR would be 111 dB, would it not? I believe the K3 was
measured at BDR of 140 dB at 2 kHz spacing on 14 MHz in the most recent ARRL
test. Not that we would actually try to operate so close to such a strong
signal on CW due to key clicks, etc, but BDR results at wider
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