On Dec 15, 2009, at 9:52 AM, Jim Brown wrote:
...we are working on the signal to noise ratio, NOT LOUDNESS. It's apples and
oranges! The only thing in common is that we're using a log ratio to
describe it.
I couldn't agree more with Jim on this one. In our business, we are trying
to
On Dec 3, 2009, at 9:25 AM, Ralph Parker wrote:
For all you young whipper-snappers with two letter calls who don't believe it:
9 Mc. SSB mixed +/- with a 5 Mc. VFO did indeed result in opposite sidebands.
I was there.
No a 9 MHz IF will not swap sidebands. But, as N1AL has mentioned, a 5
On Nov 4, 2009, at 4:41 PM, Steve Ellington wrote:
4. Example: A full wave dipole center fed with 50 ohm coax. SWR reads
infinite at the antenna but with 1/4 wavelenth of coax, SWR reads low!
Nope -- the *impedance* at the end of a 1/4 wave transmission line
when it is looking at a very
On Nov 4, 2009, at 5:05 PM, Steve Ellington wrote:
It's called a transmission line transformer and is very common.
Yes, we all know about them. Just walk 180 degrees on a constant SWR
circle on the Smith Chart, with the transmission line impedance at the
center of the Smith Chart (or use
On Oct 7, 2009, at 10/76:50 AM, Radio Amateur N5GE wrote:
You're experiencing why I stopped using Apple Computers and developing
software for them in 1985.
They are good computers but Apple does not make it easy for developers
to create software for their computers (very expensive
On Sep 2, 2009, at 9/29:26 AM, Kjeld Holm wrote:
Just now I noticed that for the last second or so of the
transmission it
seems like I have full output also on 80 meters. BUT it is not a
question of
warming up as the full output is seen only for the last second
whether I am
On Jul 28, 2009, at 12:02 PM, Iain MacDonnell - N6ML wrote:
If the Mac is one of the reasonably recent Core (2) Duo models, it
should be
able to handle the EMU-0202 at full b/w...
Unless E-MU has updated their Mac OS X drivers recently, you can use
the E-MU 0202 and 0404 only up to 96k
On Jul 28, 2009, at 12:14 PM, Kok Chen wrote:
Unless E-MU has updated their Mac OS X drivers recently, you can use
the E-MU 0202 and 0404 only up to 96k samples/sec with a Mac
My mistake.
Iain has informed me that the original poster has intended to use
Bootcamp. In that case, the E-MU
In the human fovea (where all the resolving mechanism is), there are
fewer S-cones (blue sensitivity) than there are M-cones (green) and L-
cones (red).
Quoting Malacara (Color Vision and Colorimetry:Theory and
Applications, ISBN 0-8194-4228-3): [the Blue S-cones] do not
contribute to
On May 16, 2009, at 11:26 AM, Craig Smith wrote:
I think you have arrived at a good understanding of the benefits/
limitations of both the StepIR and the remote tuner approaches. I
use the remote tuner approach, but would think that the StepIR
should give similar results.
Bear in mind
On Mar 16, 2009, at 3/161:13 AM, David Woolley (E.L) wrote:
Before doing that, please consider not using JPEG for the images.
This
sort of image is blurred by JPEG encoding and normally compresses
poorly.
Before making a statement like that, you might want to run the actual
I don't have the L and C values for the K2 tuner, but if you want to
see what impedances can be transformed from 50 ohms using the KAT100,
you can take a look at these images:
http://homepage.mac.com/chen/Technical/Tuner/T3580.jpg
http://homepage.mac.com/chen/Technical/Tuner/T14080.jpg
On Mar 15, 2009, at 11:35 AM, Kok Chen wrote:
The blue dots are for transceiver : ( shunt C : series R ) : antenna.
Oops, I meant transceiver : ( shunt C : series L ) : antenna.
73
Chen, W7AY
__
Elecraft mailing list
Home: http
On Mar 5, 2009, at 3/55:26 AM, Igor Sokolov wrote:
Bob, does it mean that the USB sound card built into MicrokeyerII
cannot be
utilized by LP-PAN? Why?
Not that you cannot use just any garden variety sound cards, but there
are at least two reasons to use a better sound card with an
On Feb 26, 2009, at 7:01 AM, Brian Alsop wrote:
I think it is a bit ironic that for RTTY, external TNC's have become
passe in favor of direct computer decode/encode.
Just a property of how computers handle audio.
USB Sound Cards go through what are called Isochronous Transfer of
USB.
On Feb 15, 2009, at 2/158:58 AM, Guy Olinger, K2AV wrote:
Taking the DATA A readings below at face value, the more than 2 db
bump
around 1000 Hz is rather startling. I'm not sure what could cause
that, but
at least to me that seems to be screaming for an explanation.
There's an
If you really need a terminal emulator and can't whip one up quickly,
you can try the one that is built into AVR Tools:
http://homepage.mac.com/chen/w7ay/AVR%20Tools/index.html
Use the download tab at the top of the page.
Once launched, just select New Session from the file menu, then tab
On Feb 10, 2009, at 2/109:09 AM, wayne burdick wrote:
While it is possible to attenuate some spurious responses by moving
coax cables around, there is a firmware-based approach that we're
working on. The general idea is to shift the 1st LO and BFO a small
amount, simultaneously, when the
On Jan 31, 2009, at 9:16 PM, Joe Subich, W4TV wrote:
For the device in question, Griffin iMic, this doesn't seem to be the
case. It does not separate enumerations for independently setting
left
and right input gain. It does support stereo input, just not two
mic/line gain controls.
I
On Jan 22, 2009, at 10:16 AM, Simon (HB9DRV) wrote:
A good soundcard will not suffer from intermod - just like a good
radio.
Not just with intermod, but many mediocre sound cards also suffer from
bad second harmonic distortion that could be more troublesome than IMD.
I have measured poor
On Jan 17, 2009, at 1/173:00 AM, hb9ari wrote:
I can imagine that digimodes software generate ± complex audio
signals,
then we can adjust this audio level to allow TX chain, including
PA, to work in a
linear zone.
Out of the common HF digital modes, I believe that BPSK31 and
On Dec 31, 2008, at 2:54 PM, dalspa...@comcast.net wrote:
I am experiencing the same issue and have been for a while. It
occurs for me without being in the text mode. Lyle says he is aware
of it and is working on a solution. I think it has gotten worse in
recent releases. I tried this
The odd thing is that the glitches in Iain's recording appear to occur
a cycle or two before a frequency shift. It almost appears to be due
to an improperly windowed FIR filter, but it could be caused by
anything else...
If you have an audio editing program, you can see the envelope
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
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 Nov 17, 2008, at 10:06 AM, Tayloe Dan-P26412 wrote:
Band noise from one receiver at
any instant in time will look exactly like band noise from
the second receiver.
That is true if the two receivers are tuned to the same passband and
you are using an identical antenna for the two
On Nov 17, 2008, at 1:01 PM, Tayloe Dan-P26412 wrote:
How can it hurt the SNR?
Because in split operation, you are adding the noise from two
different bandpasses, yet you are only hearing the signal from the
original single receiver.
Let receiver (1) hear s(t) + n1(t) and receiver (2)
On Nov 17, 2008, at 3:01 PM, Kok Chen wrote:
Prob( (s+n1+n2)^2 ) = Prob(s^2 + n1^2 + n2^2 + n1.n2 + s.n1 +
s.n2). If s, n1 and n2 are uncorrelated, then Prob(n1.n2) =
Prob(s.n1) = Prob(s.n2) = 0.
Whoops, that should be
Prob( (s+n1+n2)^2 ) = Prob(s^2 + n1^2 + n2^2 + 2.n1.n2 + 2.s.n1
On Nov 16, 2008, at 1:52 PM, Joe Subich, W4TV wrote:
Assuming equal volume settings and equal bandwidths in the two
receivers, the S/N will degrade by 6 dB (twice the noise voltage).
Unless the noise is correlated, the probability density function from
summing two random variables causes
On Oct 26, 2008, at 10/268:54 AM, Benson wrote:
I hope to order a K3 next month and need to sell some equipment
first. Can I sell the Tigertronics SignaLink USB if I intend to
connect the K3 directly to the computer sound card? Or is an
intermediate interface desirable?
If you are
On Oct 7, 2008, at 12:18 PM, Julian, G4ILO wrote:
David Ferrington, M0XDF wrote:
Thanks Julian, what the length of the delay?
200ms.
For what its worth, I just wrote a quick test.
Environment
K3 FW 2.23
Computer: PowerMac 2x2.3 GHz, Mac OS X 10.5.3
Serial Port: Keyspan
On Sep 19, 2008, at 2:32 PM, Bob Cunnings wrote:
Yes transmit is restricted - to the 2.7 (or 2.8) kHz filter. Hence the
request to allow transmit using the 6 KHz filter, at least to same
extent as receive (up to 4KHz currently).
We all agree that you can receive in a wide passband (even as
On Sep 16, 2008, at 5:07 PM, Augie Hansen wrote:
Jim Brown wrote:
...
Hold on a minute. We cannot sit over in our little corner and
pretend that the rest of the world does not exist. That's how we
got into trouble with the KIO3.
dBV is a voltage measure with a reference of 1V RMS. It's an
On Sep 16, 2008, at 5:38 PM, Joe Subich, W4TV wrote:
I suppose when Wayne has time, he can modify the display
driver to light two fewer segments so the V is v.
That is probably no good either.
dBv is the deprecated version of dBu. It was changed from dBv to dBu
because it was too easy to
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