Hmmm 2 year degree of 45 years. Old farts are kept in Funkenwagnal Jars to keep
the essence in tack, so when opened the sound can reverb within the nostrils.
Jim K9TFSent from my T-Mobile 4G LTE Device
__
Elecraft mailing list
Home:
r 16, 2020 5:27 AM
To: j...@audiosystemsgroup.com
Cc: Elecraft@mailman.qth.net
Subject: Re: [Elecraft] Why predistortion ?
H, my EE degree is only 37 years old and the term also seems clear and
descriptive to me too hmmm wonder if that also makes me an old fart???
73 es God. bless,
H, my EE degree is only 37 years old and the term also seems clear and
descriptive to me too hmmm wonder if that also makes me an old fart???
73 es God. bless,
Art/K0ACP
Sent from my iPad
> On Sep 15, 2020, at 8:24 PM, Jim Brown wrote:
>
> On 9/15/2020 3:55 PM, Andy Durbin wrote:
Usually called adaptive optics these days. The laser is a "guide star".
73,
Brian, K0DTJ
> On Sep 15, 2020, at 16:39, Fred Jensen wrote:
>
> Didn't the term "pre-distortion" originate in the astronomy world where one
> creates an artificial star with a powerful laser, and then distorts the
Well part of the problem with the original Hubble lenses where they were
miss ground in the 1st place
Paul KB9AVO
On Tue, Sep 15, 2020, 9:57 PM Fred Jensen wrote:
> Isn't that what they did to Hubble originally?
>
> 73,
>
> Fred ["Skip"] K6DGW
> Sparks NV DM09dn
> Washoe County
>
> On
Isn't that what they did to Hubble originally?
73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County
On 9/15/2020 5:41 PM, Drew AF2Z wrote:
That's funny, I was also thinking of astronomy-- the
Schmidt-Cassegrain telescope where the inherent aberrations of the
relatively simple spherical
That's funny, I was also thinking of astronomy-- the Schmidt-Cassegrain
telescope where the inherent aberrations of the relatively simple
spherical mirror is corrected (pre-distorted?) with a lens...
73,
Drew
AF2Z
On 09/15/20 18:39, Fred Jensen wrote:
Didn't the term "pre-distortion"
On 9/15/2020 3:55 PM, Andy Durbin wrote:
Who ever coined the term "predistortion" should be taken behind the bicycle
shed and introduced to a 2x4. The terminology is the epitome of obfuscation!
Hmmm. My EE degree is 56 years old, but the term seems quite clear and
descriptive to an old
Didn't the term "pre-distortion" originate in the astronomy world where
one creates an artificial star with a powerful laser, and then distorts
the telescope mirror in real time to minimize atmospheric effects
[twinkling]? That also reduces the twinkle on real nearby stars too.
Maybe that's
> The terminology is the epitome of obfuscation!
Not at all ... "predistortion" has been used in TV broadcasting for
more than 40 years - even back in analog TV. It started as simple
non-linear amplifiers ("proc amps") perhaps 75 years ago to adjust
for the different levels of compression in
Here on the ranch we call it "IMD optimization."
Wayne
> On Sep 15, 2020, at 3:55 PM, Andy Durbin wrote:
>
> " Now I understand better what the discussion is all about."
>
> Who ever coined the term "predistortion" should be taken behind the bicycle
> shed and introduced to a 2x4. The
Yes.
On 9/14/2020 9:10 AM, Joe Subich, W4TV wrote:
On 2020-09-14 7:29 AM, Charlie T wrote:
>
However, implementing the pre-distortion function IS probably a
better long-term solution.
Pre-distortion on a 12V rig only hides the problem. Any "home
station" rig should have 28/50 V finals
" Now I understand better what the discussion is all about."
Who ever coined the term "predistortion" should be taken behind the bicycle
shed and introduced to a 2x4. The terminology is the epitome of obfuscation!
Andy, k3wyc
__
Many factors influence how wide the signal is in SSB, not just IMD3 numbers.
These are:
1. Quality of ALC. Here K3 is excellent. FT in class A poor.
2. Overdriving the amp. Operators choice or ignorance.
3. Transmit bandwidth. Could be 300-2400 in contests. No adjustment in K3
except by
On 9/14/2020 9:52 AM, Dave B via Elecraft wrote:
> Pre-distortion is often used in modern cellular base-station
> transmiters, and perhaps digital broadcast systems where they have to
> handle multiple carriers simultaneously, "at power".
At the beginning of this discussion I was confusing
On 9/14/2020 5:21 PM, JR wrote:
Parenthetically, K9YC created that particular document specifically in
response to my request on another reflector for quantification relative
to unsubstantiated claims contradicting what ARRL Lab guru Bob Alison,
WB1GCM, told me.
That piece I compiled came
Mr. Wayne said -- "On the other hand, our transceivers are best
in class in terms of transmitted keying bandwidth. See paper by
K9YC for example. Perhaps that's what JR was thinking of."
YES, that is EXACTLY what I was
I ordered my K3 in 2008. The K3s was a modest upgrade. The processing power to
accomplish predistortion has only become affordable in the last few years and
is far beyond the capacity remaining in the 12 year old K3.
Jim abt
On Sep 14, 2020, at 4:44 PM, IK4EWX wrote:
Why it seem so
ths, the cost savings at the high
power stages become significant, once the software is developed and
fully engineered.
73.
Dave G0WBX.
On 14/09/2020 17:00, elecraft-requ...@mailman.qth.net wrote:
Re: [Elecraft] Why predistortion ?
--
Created on and sent from a Unix like PC running
Why it seem so difficult thing for the great Elecraft rigs?
Apache Labs Anan rigs, from 2.700 to 4.400 $, all have predistortion
included.
Are their power supply with higher voltages than the 12V of Elecraft?
Ian Ik4EWX
--
Sent from: http://elecraft.365791.n2.nabble.com/
: [Elecraft] Why predistortion ?
DC to DC is used in video and RF frequency, over 50 years I know of,all the
time to get away from 60hz and other design nonlinearities.
Retired NIST DC to 18GHz lab tech
AB7CE Roy
-Original Message-
From: Dr. William J. Schmidt
Sent: Monday, September 14
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Why predistortion ?
Always tradeoffs to be made. Boosting 12V volts to 50V means some sort of
converter that can add its own distortion products, plus expense and
additional complexity (read that "reliability") and efficiency. There's no
free
*The Elecraft K-Line already produces some of the cleanest, puresttransmit
signals around.*
Au contraire! I'm in a morning roundtable where four use K3Ss --- all four
have an unacceptable (only 32 dB down) popup on the opposite sideband
on certain peaks. It has always puzzled me why Elecraft, so
n IS probably a better
long-term solution.
73, Charlie k3ICH
-Original Message-
From: elecraft-boun...@mailman.qth.net On
Behalf Of David Gilbert
Sent: Monday, September 14, 2020 12:43 AM
To: Elecraft Reflector
Subject: Re: [Elecraft] Why predistortion ?
Of course, but that's a con
email: b...@wjschmidt.com
-Original Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Charlie T
Sent: Monday, September 14, 2020 6:30 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Why predistortion ?
Maybe I'm missing something here, bu
-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Charlie T
Sent: Sunday, September 13, 2020 9:42 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Why predistortion ?
According to Rob Sherwood, the Collins 32S-3 produces the cleanest SSB
signal
Reflector
Subject: Re: [Elecraft] Why predistortion ?
Of course, but that's a conscious choice by Elecraft and it does not result in
the "cleanest, purest signals around." I give Elecraft tons of credit for the
other measures they have take to produce good signals, which is
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Why predistortion ?
I don't know where you got the idea that the K-Line produces the cleanest
signals. As several people have pointed out, because of the 12 volt finals the
transmit IMD performance of the existing K-line is relatively poor
Of course, but that's a conscious choice by Elecraft and it does not
result in the "cleanest, purest signals around." I give Elecraft tons
of credit for the other measures they have take to produce good signals,
which is why I own and will keep my upgraded K3 probably forever, but
K8JHR
On 9/13/2020 3:03 PM, Wayne Burdick wrote:
Virtually all class-AB-biased amplifier stages have worst-case 3rd-order IMD in
the range of -30 dBc (ARRL method) on some HF bands. This reflects a limitation
in the state of the art.
I hope that this feature will be implemented for CW as well. CW
On 9/13/2020 2:32 PM, JR wrote:
The Elecraft K-Line already produces some of the cleanest, purest
transmit signals around. Do we need predistortion ?
If you care about a clean signal, YES! If you don't mind being a bad
neighbor, no.
73, Jim K9YC
12 volts is a severe constraint for MOSFET PAs. But, like a lot of other
manufacturers, we accept this constraint so the equipment can be used in a wide
variety of portable/emergency power situations. As a result we have IMD numbers
in exactly the same range as other products that are subject
Wayne is right, it's the right thing to do. And we amateurs try
to produce the best signals we can. (Ignore the wide CW signals
during contests. :-) )
But the value will also show up during multi-op situations like
running 14A during field day. Field day is much more fun if
everyone gets a
I don't know where you got the idea that the K-Line produces the
cleanest signals. As several people have pointed out, because of the 12
volt finals the transmit IMD performance of the existing K-line is
relatively poor.
Dave AB7E
On 9/13/2020 2:32 PM, JR wrote:
Why are so many ops
wayne,
After you have the K4 fully put to bed, for your next project you might want to
consider an amp that is directly driven by an I/Q stream. The amplifier will
be much more efficient (less power consumption) and you start out with less IMD
before any pre-distortion.
Sent from my iPad
You're kidding, right?
Wes N7WS
On 9/13/2020 2:32 PM, JR wrote:
The Elecraft K-Line already produces some of the cleanest, purest transmit
signals around
Thanks and Happy Trails to all. K8JHR
__
Elecraft mailing list
Here's a demonstration of predistortion in use (relevant part starts at the
10-minute point):
https://www.youtube.com/watch?v=0adHZOTqTlQ
John AE5X
https://ae5x.blogspot.com
>Why are so many ops obsessed with predistortion?
__
Elecraft
I can testify to the effectiveness of predistortion techniques from my 5
years or so as a CDMA Cellular Base Station engineer with Motorola. The
first generation of CDMA transmitters had a very specific "spectral
mask" that had to be certified. As I recall, the transmitter output that
met the
Well put.
TKS,
73 ED W2RF
-Original Message-
From: elecraft-boun...@mailman.qth.net On
Behalf Of Wayne Burdick
Sent: Sunday, September 13, 2020 6:03 PM
To: JR
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Why predistortion ?
Hi JR,
Virtually all class-AB-biased amplifier
Hi JR,
Virtually all class-AB-biased amplifier stages have worst-case 3rd-order IMD in
the range of -30 dBc (ARRL method) on some HF bands. This reflects a limitation
in the state of the art. Even with adequate feedback and bias, an amplifier
operated in the vicinity of its 1 dB compression
Why are so many ops obsessed with predistortion?
The Elecraft K-Line already produces some of the cleanest, purest
transmit signals around. Do we need predistortion ? If so, why, and
how much better is it than what we already have? Should I wait to buy a
new rig until that is available?
41 matches
Mail list logo
