On Monday, July 28, 2014 10:00:36 PM Jim Brown wrote:
Online chatter about what rigs were used at WRTC and why got me to
pursuing something that's been bugging me for a long time -- the band
pollution produced by many of today's transmitters. K6XX tackled it in
talk to NCCC last fall, and over
NI0G
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Brown
Sent: Sunday, September 07, 2014 3:00 PM
To: 'TopBand'
Subject: Topband: Rig Comparisons For Transmitted Noise
Over the last decade or so, Rob Sherwood's extensive work on receiver
Over the last decade or so, Rob Sherwood's extensive work on receiver
performance has done much to improve the receivers in modern rigs, but
transmitters have been sadly neglected.
A month or so ago I began work on a project to compare ARRL test data
for selected rigs, focusing on the trash
Maybe I didn't read the right paper.
Like I said, this paper is clearly
not on the same page with what Paul C. said.
Paul, can you point us to the correct paper
to read? Rick N6RK
Rick,
You likely read it right but the report implies too much emphasis on
needing LDMOS devices to achieve
; topband@contesting.com
Subject: Re: Topband: Rig Comparisons
On 8/2/2014 7:53 PM, James Wolf wrote:
Rick,
Is the report public? Do you have a link to it?
Jim - KR9U
This is the report I read; it was at the top of the Google search results:
http://www.wavenode.com/PureSignal.pdf
Maybe I
You¹ll final several references of ANAN users who have improved internal
transceiver shielding so that RF detection comes only from the sample port
and not internal leakage. Otherwise, the ADP algorithm is trying to
simultaneously correct for non-linearity of two amplifiers (internal and
Tom,
Also consider a situation where a solid-state transceiver is driving a class B
amp with, for example, -20 dBc 3rd order IMD -- and that IMD is much worse than
the driving transmitter. In that case ADP is correcting IMD products where IMD
is generated primarily from the amp.
Paul, W9AC
Sorry for the dyslexia. I've been meaning to type APD, not ADP.
Paul, W9AC
Sent from my iPhone5
On Aug 3, 2014, at 10:58 AM, Paul Christensen w...@arrl.net wrote:
Tom,
Also consider a situation where a solid-state transceiver is driving a class
B amp with, for example, -20 dBc 3rd
I think it depends on how much of the r in sdr is sd. The k3 does all
the baseband modulation/demodulation in DSP, but has a pretty conventional IF
path. Some people consider the K3 an SDR because it doesn't have a conventional
analog modulation/demodulation stage and uses the DSP for more
Hi Bill,
Well your choice of SDR is a later iteration. I am playing with the
older iteration that functions similar to a direct conversion receiver
with the 4X local oscillator and a quadrature detector ahead of the SDR
software on the computer. If we are not to call that SDR as it has been
the linearity of amplifiers and
reduce intermodulation distortion products emitted by software-defined
transmitters.
Mike N2MS
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Brown
Sent: Tuesday, July 29, 2014 1:01 AM
To: 'TopBand'
Subject: Topband: Rig
On 8/2/2014 9:06 AM, Michael St. Angelo wrote:
Jim,
The Mobility industry has been using pre-distortion. It has finally been
implemented in the Hermes and Apache Labs Transceivers by Warren C. Pratt.
He has won the ARRL Technical Innovation award and justly deserves it:
Interesting technique.
Sent: Saturday, August 2, 2014 11:32 AM
To: 'TopBand'
Subject: Re: Topband: Rig Comparisons
On 8/2/2014 9:06 AM, Michael St. Angelo wrote:
Jim,
The Mobility industry has been using pre-distortion. It has finally
been implemented in the Hermes and Apache Labs Transceivers by Warren C.
Pratt.
He
Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Richard
(Rick) Karlquist
Sent: Saturday, August 02, 2014 4:22 PM
To: Michael St. Angelo; j...@audiosystemsgroup.com; 'TopBand'
Subject: Re: Topband: Rig Comparisons
* The 2014 ARRL Technical Innovation Award went
...@audiosystemsgroup.com; 'TopBand'
topband@contesting.com
Sent: Saturday, August 02, 2014 7:06 PM
Subject: Re: Topband: Rig Comparisons
It really doesn't matter how much power the amplifier is outputting. A
simple explanation is that a sample of the output is inversely fed back
and
combined
On 8/2/2014 4:06 PM, James Wolf wrote:
It really doesn't matter how much power the amplifier is outputting. A
simple explanation is that a sample of the output is inversely fed back and
combined with the input. As was mentioned before, this method has been
around for a long time. When you
I read the technical report on Pure Signal and it
sounds like what we used to call a hero experiment
in the research lab where I worked, consisting of a
few impressive results, but with many disclaimers,
and nothing you could productize. What is supposed
to be new is the adaptive part, but it
On 2014-08-02 17:46, Paul Christensen wrote:
Their implementation of adaptive pre-distortion (APD) works very well
even without well behaved amps and substantial IMD improvement is
easily attained with existing bipolar transistor, FET, and vacuum tube
amps. I have personally witnessed
Rick,
Is the report public? Do you have a link to it?
Jim - KR9U
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Richard
Karlquist
Sent: Saturday, August 02, 2014 9:17 PM
To: topband@contesting.com
Subject: Re: Topband: Rig Comparisons
On 2014-08
On 8/2/2014 7:53 PM, James Wolf wrote:
Rick,
Is the report public? Do you have a link to it?
Jim - KR9U
This is the report I read; it was at the top
of the Google search results:
http://www.wavenode.com/PureSignal.pdf
Maybe I didn't read the right paper.
Like I said, this paper is
Online chatter about what rigs were used at WRTC and why got me to
pursuing something that's been bugging me for a long time -- the band
pollution produced by many of today's transmitters. K6XX tackled it in
talk to NCCC last fall, and over the weekend, when IOTA was slow (which
was a lot of
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