Re: [Elecraft] Why predistortion ?

[Jim Brown]

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 from Bob's raw data. In essence, I plotted 
data for that select list of products on the same graph, with the scale 
large enough to compare each product. The plots were of running averages 
of adjacent data points to smooth it, again to make it more readable.


73, Jim K9YC




__
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 

Re: [Elecraft] Overlapping K2 upgrades?

[Ed]

I have ALL the upgrades as far as I know, but for my original Field Test K2 
SN 00057 I stopped at CW only. I have (I think) ALL the upgrades/updates 
and SSB and the 100W kit. I guess that all I can do is go through ALL of it 
and try to make sense/sure everything is in order. (???)

Ed N4XY
On September 15, 2020 12:44:08 AM Don Wilhelm  wrote:


Doug,

If you have the most current upgrade kits, there is no overlap.  OTOH if
you have older upgrade kits such as the BFO upgrade, there were changes.

73,
Don W3FPR

On 9/14/2020 7:49 PM, Douglas Hagerman via Elecraft wrote:
I am starting to apply the accumulated Elecraft upgrades to an early K2. Do 
any of them overlap? Is there a preferred sequence I should follow?

__
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...@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 arch...@mail-archive.com 

Re: [Elecraft] Overlapping K2 upgrades?

[Don Wilhelm]

Doug,

If you have the most current upgrade kits, there is no overlap.  OTOH if 
you have older upgrade kits such as the BFO upgrade, there were changes.


73,
Don W3FPR

On 9/14/2020 7:49 PM, Douglas Hagerman via Elecraft wrote:

I am starting to apply the accumulated Elecraft upgrades to an early K2. Do any 
of them overlap? Is there a preferred sequence I should follow?

__
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 

Re: [Elecraft] [K2] Interest in assembled K2?

[Joseph M. Durnal]

They sell on here all the time.  I generally miss the ones that go for a
good price.

73 de Joe NE3R

On Mon, Sep 14, 2020 at 8:04 PM K1FFX  wrote:

> I'm starting to plan how to get through the cold months that are coming
> during which we won't be getting together with friends and family at all,
> since it will be too cold to do so outdoors.  I've been a happy K2 owner
> for
> 10 years now, having built my K2 back in the Summer/Fall of 2010. I'm now
> thinking of assembling a new K2 as a way to occupy part of the time.  I
> find
> kit-building to be an engaging and soothing activity and building a K2
> could
> be a way to help pass the time this winter.
>
> My question is: is there generally interest out there for pre-assembled
> K2s?
> I would only want to make back the cost of the kit; the time spent building
> the kit would be well worth it to me.
>
> Any thoughts on this?
>
> Thanks!
>
> - Bruce K1FFX
>
>
>
>
> -
> Bruce Rosen
> K1FFX
> K2/100 6982 KSB2 KAT100-1 KAF2 KIO2
>
> --
> Sent from: http://elecraft.365791.n2.nabble.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 joseph.dur...@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 arch...@mail-archive.com 

[Elecraft] Why predistortion ?

[JR]

   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 thinking of!   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.   I 
believe it is the only piece that compiles the available data in a 
single document.


THANK YOU for the enlightening reply, Mr. Wayne - I appreciate the leg 
up.  One can learn a lot just by asking questions.   K8JHR

__



__
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 

[Elecraft] [K2] Interest in assembled K2?

[K1FFX]

I'm starting to plan how to get through the cold months that are coming
during which we won't be getting together with friends and family at all,
since it will be too cold to do so outdoors.  I've been a happy K2 owner for
10 years now, having built my K2 back in the Summer/Fall of 2010. I'm now
thinking of assembling a new K2 as a way to occupy part of the time.  I find
kit-building to be an engaging and soothing activity and building a K2 could
be a way to help pass the time this winter.

My question is: is there generally interest out there for pre-assembled K2s? 
I would only want to make back the cost of the kit; the time spent building
the kit would be well worth it to me.

Any thoughts on this?

Thanks!

- Bruce K1FFX




-
Bruce Rosen
K1FFX
K2/100 6982 KSB2 KAT100-1 KAF2 KIO2

--
Sent from: http://elecraft.365791.n2.nabble.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 arch...@mail-archive.com 

[Elecraft] Overlapping K2 upgrades?

[Douglas Hagerman via Elecraft]

I am starting to apply the accumulated Elecraft upgrades to an early K2. Do any 
of them overlap? Is there a preferred sequence I should follow?

Doug, W0UHU. 
__
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 

Re: [Elecraft] K3: KIO3 dgital board failed (I think)

[David Gilbert]

I had exactly that same problem, Ed, and I also first thought it was the 
USB/RS232 cable (which it wasn't).  I also do not need the direct USB 
connectivity, or the associated internal sound card. Luckily, I was able 
to buy replacement boards from someone who had done the upgrade to the 
KIO3B for another ham and still had the old boards, one of which ... the 
audio board ... was itself bad but at least the RS232 board was good.  
Problem fixed.


In my case, the KIO3A apparently was damaged by a line transient that 
came in via the laptop that was connected to the USB/RS232 line.  Most 
everything was disconnected at the time, but that line wasn't.


I had sent an email to Elecraft technical support when I first had the 
problem, asking whether or not they had replacement boards or whether 
they could fix the KIO3A.  The tech didn't bother to answer either of 
those questions and simply replied with a rather curt "just upgrade to 
the KIO3B ... you'll be happier".


Somebody could probably make a small business gathering various older 
K3/K3s boards from folks who had done various upgrades in order to 
service users like us who can't get help anymore from Elecraft.


73,
Dave   AB7E



On 9/14/2020 1:43 PM, Edward R Cole wrote:

My K3 SN 4340 bought in 2010 apparently has a failure in the RS232 I/F.

My computer says the FDTI cable is working and using com port-6 but 
there is no connection using the K3 Utility or WSJT-X which was 
running fine in July.  The radio no longer keys up on computer boot-up 
as before.  I bought another FDTI USB/RS232 conversion cable and it 
does not work wit the K3, either.  I checked the com port and cable 
via Device Manager and both are shown as working with no problems.  I 
even used my second computer to test the cables (also showing working 
well).  Computers are i5 running win10pro64.


I contacted Elecraft Service Dept on Friday so waiting to hear back 
from them.


I gave a passing thought to just upgrade to the KIO3B but it totals 
$437.80 before shipping.  I don't really need the USB I/F for my use 
of the K3.  I use two com ports to support control of the K3 (I won't 
bother you with details) to run MAP65 and TRAKBOX programs 
simultaneously.  But just have the single com port recently in use 
with WSJT-X.


I guess I wonder if anyone else has had this failure?

73, Ed - KL7UW


__
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 

Re: [Elecraft] K3: KIO3 dgital board failed (I think)

[Nr4c]

Oh yes. And the only way out is to upgrade the whole system.  Or look for used 
items here. 

Sent from my iPhone
...nr4c. bill


> On Sep 14, 2020, at 4:48 PM, Edward R Cole  wrote:
> 
> My K3 SN 4340 bought in 2010 apparently has a failure in the RS232 I/F.
> 
> My computer says the FDTI cable is working and using com port-6 but there is 
> no connection using the K3 Utility or WSJT-X which was running fine in July.  
> The radio no longer keys up on computer boot-up as before.  I bought another 
> FDTI USB/RS232 conversion cable and it does not work wit the K3, either.  I 
> checked the com port and cable via Device Manager and both are shown as 
> working with no problems.  I even used my second computer to test the cables 
> (also showing working well).  Computers are i5 running win10pro64.
> 
> I contacted Elecraft Service Dept on Friday so waiting to hear back from them.
> 
> I gave a passing thought to just upgrade to the KIO3B but it totals $437.80 
> before shipping.  I don't really need the USB I/F for my use of the K3.  I 
> use two com ports to support control of the K3 (I won't bother you with 
> details) to run MAP65 and TRAKBOX programs simultaneously.  But just have the 
> single com port recently in use with WSJT-X.
> 
> I guess I wonder if anyone else has had this failure?
> 
> 73, Ed - KL7UW
>  http://www.kl7uw.com
> Dubus-NA Business mail:
>  dubus...@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 n...@widomaker.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 arch...@mail-archive.com 

[Elecraft] Continuing saga with Tx Inhibit and the KX3 - possible firmware bug?

[Chris Cox, N0UK]

Having solved the need for getting +Ve Tx Inhibit working on my KX3/10GHz 
Transverter integration using a mosfet switch to invert the signal and 
configured the KX3 for 0v Tx Inhibit, I had opportunity to test it out this 
afternoon.

The solution seemed to work fine on SSB but I now have a weird issue when using 
the rig on CW.

If I manually select transmit with the microphone PTT and then wait for the 
transverter sequencing to remove Tx Inhibit and then key CW with the paddles, 
the system works as desired.

If I key the system using VOX, the Tx Inhibit functions correctly, fully 
disabling the transmitter from producing RF until TxInhibit is removed BUT the 
CW sidetone becomes permanently on from the moment TXInh disappears regardless 
of whether I am sending or not.  It stays present until I press any of the 
buttons on the KX3.   This happens regardless of which band is enabled, but 
occurs whenever TxInhibit is present.

If I remove the TXInh fro the GPIO input (but leave the option enabled in the 
KX3 config) the rig operates normally.

Can anyone else replicate this oddball behavior?  It seems to be a firmware 
bug.  I have tried removing power but that does not alter the effect.

Again, all works just fine if I don’t try to key the paddles before PTT 
sequencing has changed over.

Chris Cox, N0UK
chr...@chris.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 arch...@mail-archive.com 

Re: [Elecraft] Why predistortion ?

[Jim Miller]

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 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 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 j...@jtmiller.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 arch...@mail-archive.com 

Re: [Elecraft] Why predistortion ?

[Dave B via Elecraft]

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".


It dramatically reduces transmitted intermodulation to very low levels, 
allowing such multi carrier systems to co-exist very close to each 
other, improving the reception of the base station by the mobile/handset 
device.  (Lower Bit Error Rate numbers.)  Without spending mega bucks 
for a PA system grossly over rated and inefficient, just to stay in it's 
very linear region, well below the 1dB compression point!  (As was 
common not that long ago.)


As mobile phones these days are also almost all SDR in nature, even they 
may apply pre-distortion to their TX signal, for the same reason.  
Smaller lower cost and lower power consumption PA, but keeping it clean.


"Docherty Amplifier" systems are also often used in other cases, where a 
clean low power class A amp in effect "corrects" the output of a much 
more powerful, more efficient but not as linear (class B) amplifier by 
means of a combiner, dynamically adding or subtracting "signal" as 
needed in analogue real-time.  (Crude over simplification!)


The techniques are as yet not common in Amateur circles, but are 
becoming widely used in several commercial scenarios, so it is only a 
matter of time...  As more and more mainstream radio transceivers adopt 
SDR principles in both RX and TX paths, 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 and using free and open source 
software:

__
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 

[Elecraft] K3: KIO3 dgital board failed (I think)

[Edward R Cole]

My K3 SN 4340 bought in 2010 apparently has a failure in the RS232 I/F.

My computer says the FDTI cable is working and using com port-6 but 
there is no connection using the K3 Utility or WSJT-X which was 
running fine in July.  The radio no longer keys up on computer 
boot-up as before.  I bought another FDTI USB/RS232 conversion cable 
and it does not work wit the K3, either.  I checked the com port and 
cable via Device Manager and both are shown as working with no 
problems.  I even used my second computer to test the cables (also 
showing working well).  Computers are i5 running win10pro64.


I contacted Elecraft Service Dept on Friday so waiting to hear back from them.

I gave a passing thought to just upgrade to the KIO3B but it totals 
$437.80 before shipping.  I don't really need the USB I/F for my use 
of the K3.  I use two com ports to support control of the K3 (I won't 
bother you with details) to run MAP65 and TRAKBOX programs 
simultaneously.  But just have the single com port recently in use with WSJT-X.


I guess I wonder if anyone else has had this failure?

73, Ed - KL7UW
  http://www.kl7uw.com
Dubus-NA Business mail:
  dubus...@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 arch...@mail-archive.com 

Re: [Elecraft] Elecraft Digest, Vol 197, Issue 18

[Alan - G4GNX]

For goodness sake, please trim your posts!!! ;-(

73,

Alan. G4GNX


-- Original Message --
From: ccolema...@gmail.com
To: elecraft@mailman.qth.net
Sent: 14/09/2020 21:10:47
Subject: Re: [Elecraft] Elecraft Digest, Vol 197, Issue 18




Sent from my iPhone


 On Sep 14, 2020, at 11:03 AM, elecraft-requ...@mailman.qth.net wrote:

 Send Elecraft mailing list submissions to
elecraft@mailman.qth.net

 To subscribe or unsubscribe via the World Wide Web, visit
http://mailman.qth.net/mailman/listinfo/elecraft
 or, via email, send a message with subject or body 'help' to
elecraft-requ...@mailman.qth.net

 You can reach the person managing the list at
elecraft-ow...@mailman.qth.net

 When replying, please edit your Subject line so it is more specific
 than "Re: Contents of Elecraft digest..."


 Today's Topics:

   1. Why predistortion ? (JR)
   2. Re: Why predistortion ? (Wayne Burdick)
   3. Re: Why predistortion ? (E.H. Russell)
   4. Re: Why predistortion ? (Randy Farmer)
   5. KAT500: Fails to tune,and shows 3:1 on good antenna on 18
  MHz. (Dave Cole)
   6. Re: KAT500: Fails to tune,and shows 3:1 on good antenna on
  18 MHz. (Dick Dievendorff)
   7. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on
  18 MHz. (Ken Winterling)
   8.  Why predistortion ? (John Harper)
   9. Re: Why predistortion ? (Wes)
  10. Re: Why predistortion ? (W2xj)
  11. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on
  18 MHz. (Dave Cole)
  12. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on
  18 MHz. (Dave Cole)
  13. Re: Why predistortion ? (David Gilbert)
  14. Re: Why predistortion ? (Bill Frantz)
  15. Re: Why predistortion ? (Wayne Burdick)
  16. Re: Why predistortion ? (Jim Brown)
  17. Re: Why predistortion ? (Jim Brown)
  18. Re: Why predistortion ? (David Gilbert)
  19. Elecraft CW Net Report (kevinr)
  20. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on
  18 MHz. (Dave Cole)
  21. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on
  18 MHz. (Ken Winterling)
  22. 630 meter operation on the K4 (Nigel Lemaire)
  23. Re: Why predistortion ? (Charlie T)
  24. Re: Why predistortion ? (Charlie T)
  25. Re: Why predistortion ? (Dr. William J. Schmidt)


 --

 Message: 1
 Date: Sun, 13 Sep 2020 17:32:21 -0400
 From: JR 
 To: Elecraft@mailman.qth.net
 Subject: [Elecraft] Why predistortion ?
 Message-ID: 
 Content-Type: text/plain; charset=utf-8; format=flowed

 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?

 Thanks and Happy Trails to all.?? K8JHR
 _


 --

 Message: 2
 Date: Sun, 13 Sep 2020 15:03:00 -0700
 From: Wayne Burdick 
 To: JR 
 Cc: elecraft@mailman.qth.net
 Subject: Re: [Elecraft] Why predistortion ?
 Message-ID: <93a9df67-0b33-4fbf-88fc-226d98d27...@elecraft.com>
 Content-Type: text/plain;charset=utf-8

 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 point (where it is 
most efficient) will exhibit such characteristics.

 To improve on this you either need to operate class A, which is highly 
inefficient, or use predistortion.

 A small number of commercial transceivers are now providing predistortion, in 
some cases as an optional/experimental setting (that not everyone uses, or at 
least not all the time). There are constraints on predistortion power range 
imposed by the headroom limit of the amplifier stage itself. Go over that point 
and distortion will be worse than without predistortion.

 Predistortion, correctly applied, can reduce interference between adjacent 
stations on a crowded band. This is a factor at least some fraction of the time 
during typical amateur radio use. Beyond that, the motivation for a ?pure? 
signal exemplifies the amateur spirit of cooperation, and is an example of 
keeping the hobby on the forefront of electrical design.

 Wayne,
 N6KR

 
 elecraft.com


 On Sep 13, 2020, at 2:34 PM, JR  wrote:

 ?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?

 Thanks and Happy Trails to all.   K8JHR
 _
 __
 Elecraft mailing list
 Home: 

Re: [Elecraft] Why predistortion ?

[IK4EWX]

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 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 

Re: [Elecraft] Elecraft Digest, Vol 197, Issue 18

[ccolemanmd]

Sent from my iPhone

> On Sep 14, 2020, at 11:03 AM, elecraft-requ...@mailman.qth.net wrote:
> 
> Send Elecraft mailing list submissions to
>elecraft@mailman.qth.net
> 
> To subscribe or unsubscribe via the World Wide Web, visit
>http://mailman.qth.net/mailman/listinfo/elecraft
> or, via email, send a message with subject or body 'help' to
>elecraft-requ...@mailman.qth.net
> 
> You can reach the person managing the list at
>elecraft-ow...@mailman.qth.net
> 
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Elecraft digest..."
> 
> 
> Today's Topics:
> 
>   1. Why predistortion ? (JR)
>   2. Re: Why predistortion ? (Wayne Burdick)
>   3. Re: Why predistortion ? (E.H. Russell)
>   4. Re: Why predistortion ? (Randy Farmer)
>   5. KAT500: Fails to tune,and shows 3:1 on good antenna on 18
>  MHz. (Dave Cole)
>   6. Re: KAT500: Fails to tune,and shows 3:1 on good antenna on
>  18 MHz. (Dick Dievendorff)
>   7. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on
>  18 MHz. (Ken Winterling)
>   8.  Why predistortion ? (John Harper)
>   9. Re: Why predistortion ? (Wes)
>  10. Re: Why predistortion ? (W2xj)
>  11. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on
>  18 MHz. (Dave Cole)
>  12. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on
>  18 MHz. (Dave Cole)
>  13. Re: Why predistortion ? (David Gilbert)
>  14. Re: Why predistortion ? (Bill Frantz)
>  15. Re: Why predistortion ? (Wayne Burdick)
>  16. Re: Why predistortion ? (Jim Brown)
>  17. Re: Why predistortion ? (Jim Brown)
>  18. Re: Why predistortion ? (David Gilbert)
>  19. Elecraft CW Net Report (kevinr)
>  20. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on
>  18 MHz. (Dave Cole)
>  21. Re: KAT500: Fails to tune, and shows 3:1 on good antenna on
>  18 MHz. (Ken Winterling)
>  22. 630 meter operation on the K4 (Nigel Lemaire)
>  23. Re: Why predistortion ? (Charlie T)
>  24. Re: Why predistortion ? (Charlie T)
>  25. Re: Why predistortion ? (Dr. William J. Schmidt)
> 
> 
> --
> 
> Message: 1
> Date: Sun, 13 Sep 2020 17:32:21 -0400
> From: JR 
> To: Elecraft@mailman.qth.net
> Subject: [Elecraft] Why predistortion ?
> Message-ID: 
> Content-Type: text/plain; charset=utf-8; format=flowed
> 
> 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?
> 
> Thanks and Happy Trails to all.?? K8JHR
> _
> 
> 
> --
> 
> Message: 2
> Date: Sun, 13 Sep 2020 15:03:00 -0700
> From: Wayne Burdick 
> To: JR 
> Cc: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] Why predistortion ?
> Message-ID: <93a9df67-0b33-4fbf-88fc-226d98d27...@elecraft.com>
> Content-Type: text/plain;charset=utf-8
> 
> 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 point (where it is 
> most efficient) will exhibit such characteristics.
> 
> To improve on this you either need to operate class A, which is highly 
> inefficient, or use predistortion. 
> 
> A small number of commercial transceivers are now providing predistortion, in 
> some cases as an optional/experimental setting (that not everyone uses, or at 
> least not all the time). There are constraints on predistortion power range 
> imposed by the headroom limit of the amplifier stage itself. Go over that 
> point and distortion will be worse than without predistortion. 
> 
> Predistortion, correctly applied, can reduce interference between adjacent 
> stations on a crowded band. This is a factor at least some fraction of the 
> time during typical amateur radio use. Beyond that, the motivation for a 
> ?pure? signal exemplifies the amateur spirit of cooperation, and is an 
> example of keeping the hobby on the forefront of electrical design.
> 
> Wayne,
> N6KR
> 
> 
> elecraft.com
> 
>> On Sep 13, 2020, at 2:34 PM, JR  wrote:
>> 
>> ?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?
>> 
>> Thanks and Happy Trails to all.   K8JHR
>> _
>> __
>> Elecraft mailing list
>> Home: 

Re: [Elecraft] K4 Second RX and VHF

[Wes]

Amen.  RIP

On 9/14/2020 11:22 AM, Randy Farmer wrote:

The demise of TMP connectors? Hooray!

73...
Randy, W8FN

On 9/14/2020 1:00 PM, Wayne Burdick wrote:
The cabling requirements are simple (coax_*with very sturdy MCX plugs*_): one 
to bring RF into the receiver module, and another to get the filtered 
receiver output signal to the digital downconverter.

__
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 wes_n...@triconet.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 arch...@mail-archive.com 

Re: [Elecraft] 630 meter operation on the K4

[Wayne Burdick]

By the way, the K4 provides a way to do direct comparative sensitivity 
measurements for both receivers. A persistent display in relative dB can be 
shown. This makes things like MDS testing very easy.

73,
Wayne
N6KR


> On Sep 14, 2020, at 11:14 AM, Jim Miller  wrote:
> 
> Nice!!
> 
> Thanks for the update!
> 
> jim ab3cv
> 
> On Mon, Sep 14, 2020 at 2:11 PM Wayne Burdick  wrote:
> You can directly set the frequency to this range. There's no need for a 
> transverter band.
> 
> Test mode will not be needed. 
> 
> For receive purposes, you can use any of the five antenna jacks. I just 
> measured the MDS at -135 dBm, which is more than satisfactory on on this band.
> 
> For transmit you'll need to use XV OUT and an external amplifier.
> 
> 73,
> Wayne
> N6KR
> 
> 
> > On Sep 14, 2020, at 10:26 AM, Jim Miller  wrote:
> > 
> > And will the K4 need to be in "Test" mode as the K3 was required?
> > 
> > jim ab3cv
> > 
> > 
> > On Mon, Sep 14, 2020 at 1:25 PM Jim Miller  wrote:
> > Will the band be evident or will it need to be added? Will there be an 
> > appropriate XV offset to allow direct reading of the frequency?
> > 
> > Thanks!
> > 
> > jim ab3cv
> > 
> > On Mon, Sep 14, 2020 at 12:35 PM Wayne Burdick  wrote:
> > The K4 has receive capability in this band, and will transmit at the XV OUT 
> > jack well in excess of 0 dBm. (More like +7.) This should be suitable for 
> > use with an external amplifier.
> > 
> > Wayne
> > N6KR
> > 
> > 
> > > On Sep 14, 2020, at 8:10 AM, Nigel Lemaire  wrote:
> > > 
> > > Wondering what capabilities the K4 will have on this (these) bands...
> > > 
> > > 73
> > > Nigel
> > > Wa6MSE
> > > __
> > > 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...@elecraft.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 j...@jtmiller.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 arch...@mail-archive.com 

Re: [Elecraft] K4 Second RX and Transverters

[Wayne Burdick]

> On Sep 14, 2020, at 10:21 AM, Jeff Uchitjil  wrote:
> 
> I have sent this question to Elecraft support a few times over the last few 
> weeks without a response, so I am giving it a try here.
> 
> If I have a basic K4 and a 2M transverter attached, will I be able to monitor 
> 6M or any other internal band off of the single main antenna port and also 
> have a 2M transverter frequency on the 2nd RX?

Hi Jeff,

If you're using an external transverter, you'd connect it to the XV IN and XV 
OUT jacks. Let's say the IF is 28 MHz. You could put one receiver on this IF 
(with a display automatically translating this to 144 MHz), while the other 
receiver is on an HF-6 meter band.

A K4D is needed to accomplish this dual-receive/different bands scenario. The 
two receivers will clearly need to use different antenna inputs, implying two 
A-to-D converter modules. 

The K4D also has a second full set of band-pass filters, preamps, and 
attenuators, optimizing performance on both receivers.

Wayne
N6KR

__
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 

Re: [Elecraft] K4 Second RX and VHF

[Randy Farmer]

The demise of TMP connectors? Hooray!

73...
Randy, W8FN

On 9/14/2020 1:00 PM, Wayne Burdick wrote:

The cabling requirements are simple (coax_*with very sturdy MCX plugs*_): one 
to bring RF into the receiver module, and another to get the filtered receiver 
output signal to the digital downconverter.

__
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 

Re: [Elecraft] 630 meter operation on the K4

[Jim Miller]

Nice!!

Thanks for the update!

jim ab3cv

On Mon, Sep 14, 2020 at 2:11 PM Wayne Burdick  wrote:

> You can directly set the frequency to this range. There's no need for a
> transverter band.
>
> Test mode will not be needed.
>
> For receive purposes, you can use any of the five antenna jacks. I just
> measured the MDS at -135 dBm, which is more than satisfactory on on this
> band.
>
> For transmit you'll need to use XV OUT and an external amplifier.
>
> 73,
> Wayne
> N6KR
>
>
> > On Sep 14, 2020, at 10:26 AM, Jim Miller  wrote:
> >
> > And will the K4 need to be in "Test" mode as the K3 was required?
> >
> > jim ab3cv
> >
> >
> > On Mon, Sep 14, 2020 at 1:25 PM Jim Miller  wrote:
> > Will the band be evident or will it need to be added? Will there be an
> appropriate XV offset to allow direct reading of the frequency?
> >
> > Thanks!
> >
> > jim ab3cv
> >
> > On Mon, Sep 14, 2020 at 12:35 PM Wayne Burdick 
> wrote:
> > The K4 has receive capability in this band, and will transmit at the XV
> OUT jack well in excess of 0 dBm. (More like +7.) This should be suitable
> for use with an external amplifier.
> >
> > Wayne
> > N6KR
> >
> >
> > > On Sep 14, 2020, at 8:10 AM, Nigel Lemaire  wrote:
> > >
> > > Wondering what capabilities the K4 will have on this (these) bands...
> > >
> > > 73
> > > Nigel
> > > Wa6MSE
> > > __
> > > 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...@elecraft.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 j...@jtmiller.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 arch...@mail-archive.com 

Re: [Elecraft] 630 meter operation on the K4

[Wayne Burdick]

You can directly set the frequency to this range. There's no need for a 
transverter band.

Test mode will not be needed. 

For receive purposes, you can use any of the five antenna jacks. I just 
measured the MDS at -135 dBm, which is more than satisfactory on on this band.

For transmit you'll need to use XV OUT and an external amplifier.

73,
Wayne
N6KR


> On Sep 14, 2020, at 10:26 AM, Jim Miller  wrote:
> 
> And will the K4 need to be in "Test" mode as the K3 was required?
> 
> jim ab3cv
> 
> 
> On Mon, Sep 14, 2020 at 1:25 PM Jim Miller  wrote:
> Will the band be evident or will it need to be added? Will there be an 
> appropriate XV offset to allow direct reading of the frequency?
> 
> Thanks!
> 
> jim ab3cv
> 
> On Mon, Sep 14, 2020 at 12:35 PM Wayne Burdick  wrote:
> The K4 has receive capability in this band, and will transmit at the XV OUT 
> jack well in excess of 0 dBm. (More like +7.) This should be suitable for use 
> with an external amplifier.
> 
> Wayne
> N6KR
> 
> 
> > On Sep 14, 2020, at 8:10 AM, Nigel Lemaire  wrote:
> > 
> > Wondering what capabilities the K4 will have on this (these) bands...
> > 
> > 73
> > Nigel
> > Wa6MSE
> > __
> > 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...@elecraft.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 j...@jtmiller.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 arch...@mail-archive.com 

Re: [Elecraft] 630 meter operation on the K4

[Jim Miller]

And will the K4 need to be in "Test" mode as the K3 was required?

jim ab3cv


On Mon, Sep 14, 2020 at 1:25 PM Jim Miller  wrote:

> Will the band be evident or will it need to be added? Will there be an
> appropriate XV offset to allow direct reading of the frequency?
>
> Thanks!
>
> jim ab3cv
>
> On Mon, Sep 14, 2020 at 12:35 PM Wayne Burdick  wrote:
>
>> The K4 has receive capability in this band, and will transmit at the XV
>> OUT jack well in excess of 0 dBm. (More like +7.) This should be suitable
>> for use with an external amplifier.
>>
>> Wayne
>> N6KR
>>
>>
>> > On Sep 14, 2020, at 8:10 AM, Nigel Lemaire  wrote:
>> >
>> > Wondering what capabilities the K4 will have on this (these) bands...
>> >
>> > 73
>> > Nigel
>> > Wa6MSE
>> > __
>> > 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...@elecraft.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 j...@jtmiller.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 arch...@mail-archive.com 

Re: [Elecraft] 630 meter operation on the K4

[Jim Miller]

Will the band be evident or will it need to be added? Will there be an
appropriate XV offset to allow direct reading of the frequency?

Thanks!

jim ab3cv

On Mon, Sep 14, 2020 at 12:35 PM Wayne Burdick  wrote:

> The K4 has receive capability in this band, and will transmit at the XV
> OUT jack well in excess of 0 dBm. (More like +7.) This should be suitable
> for use with an external amplifier.
>
> Wayne
> N6KR
>
>
> > On Sep 14, 2020, at 8:10 AM, Nigel Lemaire  wrote:
> >
> > Wondering what capabilities the K4 will have on this (these) bands...
> >
> > 73
> > Nigel
> > Wa6MSE
> > __
> > 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...@elecraft.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 j...@jtmiller.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 arch...@mail-archive.com 

[Elecraft] K4 Second RX and Transverters

[Jeff Uchitjil]

I have sent this question to Elecraft support a few times over the last few 
weeks without a response, so I am giving it a try here.

If I have a basic K4 and a 2M transverter attached, will I be able to monitor 
6M or any other internal band off of the single main antenna port and also have 
a 2M transverter frequency on the 2nd RX? Or is the transverter considered a 
second antenna and would require the K4D with he second RX path to have the two 
bands at the same time? The transverter would use the 10M IF, but I am not sure 
how the pathing works if the transverter port would be an either or with the 
main antenna without a K4D.

Jeff
K9KLD
__
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 

Re: [Elecraft] Why predistortion ?

[Dr. William J. Schmidt]

I don't think anyone said it can't be done or hasn't been done before.  It
has.  But you can't ignore the cost, reliability/ complexity, efficiency
(power and signal) of the changes.  For those of us that have actually had
to design and implement circuit changes like this at the commercial level,
it sounds trivial but that is simply not reality.


Dr. William J. Schmidt - K9HZ J68HZ  

email:  b...@wjschmidt.com



-Original Message-
From: lmarion [mailto:lmar...@mt.net] 
Sent: Monday, September 14, 2020 11:32 AM
To: Dr. William J. Schmidt ; elecraft@mailman.qth.net
Subject: Re: [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, 2020 10:05 AM
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 lunch here.

Dr. William J. Schmidt - K9HZ J68HZ

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, but it would seem to me that if an FET
linear amplifier running from 50 V or higher  is considerably cleaner than
one running from 12 V, that, for a high end rig, a simple step-up switching
supply could solve the problem.  But, that obviously adds to the cost so it
IS somewhat of a conundrum.

However, implementing the pre-distortion function 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 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 simply was
incorrect in his comment and it makes a difference when considering the
expanding focus by folks like Sherwood and others to clean up the bands.
When it comes to IMD, Elecraft is not one of the better players.  The fact
that that's by choice doesn't change anything.  I suspect that 95+% of K3
rigs are used in portable/emergency situations less than 5% of the time.

73,
Dave   AB7E



On 9/13/2020 7:14 PM, Wayne Burdick wrote:
> 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 to this
constraint.
>
> 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.
>
> 73,
> Wayne
> N6KR
>
>
>
>> On Sep 13, 2020, at 6:50 PM, David Gilbert  wrote:
>>
>>
>> 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 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?
>>>
>>> Thanks and Happy Trails to all.   K8JHR
>> __
>> 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...@elecraft.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 pin...@erols.com

__
Elecraft mailing list
Home: 

Re: [Elecraft] K4 Second RX and VHF

[Wayne Burdick]

The KRX4 option (which turns a K4 into a K4D) comes with two modules: a plug-in 
digital downconverter board, and a plug-in receiver board. One of them lives in 
the digital compartment and the other in the RF compartment, which are already 
shielded from each other, so no additional shielding is needed.

The cabling requirements are simple (coax with very sturdy MCX plugs): one to 
bring RF into the receiver module, and another to get the filtered receiver 
output signal to the digital downconverter.

The internal transverter module has its own built-in shield that doesn't have 
to be removed to do installation. But to ensure signal integrity it requires 
short, high-quality coax cables for its antenna (ANT4 on the rear panel) as 
well as for its I.F. input and output. 

73,
Wayne
N6KR


> On Sep 14, 2020, at 9:44 AM, Ed Gray W0SD  wrote:
> 
> I keep trying to find a picture for months of the inside of the K4 but I can 
> not find one so I give up and will ask?  How is the second RX handled 
> mechanically.  I just hate the box in the K3S for the second RX.  What a pain 
> as you have to take it out to do things with the filters and all the cabling 
> and routing to me is not good.  I hope this is all gone in the K4.
> 
> Secondly how will VHF be handled in the K4?  Again I am not a big fan of the 
> cabling involved in the K3S for VHF.  A plug is computer type slot, etc. sure 
> seems like it would be better.
> 
> Ed W0SD
> 
> 
> __
> 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...@elecraft.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 arch...@mail-archive.com 

[Elecraft] K4 Second RX and VHF

[Ed Gray W0SD]

I keep trying to find a picture for months of the inside of the K4 but I 
can not find one so I give up and will ask?  How is the second RX 
handled mechanically.  I just hate the box in the K3S for the second 
RX.  What a pain as you have to take it out to do things with the 
filters and all the cabling and routing to me is not good.  I hope this 
is all gone in the K4.


Secondly how will VHF be handled in the K4?  Again I am not a big fan of 
the cabling involved in the K3S for VHF.  A plug is computer type slot, 
etc. sure seems like it would be better.


Ed W0SD


__
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 

Re: [Elecraft] 630 meter operation on the K4

[Wayne Burdick]

The K4 has receive capability in this band, and will transmit at the XV OUT 
jack well in excess of 0 dBm. (More like +7.) This should be suitable for use 
with an external amplifier.

Wayne
N6KR


> On Sep 14, 2020, at 8:10 AM, Nigel Lemaire  wrote:
> 
> Wondering what capabilities the K4 will have on this (these) bands...
> 
> 73
> Nigel
> Wa6MSE
> __
> 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...@elecraft.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 arch...@mail-archive.com 

Re: [Elecraft] Why predistortion ?

[lmarion]

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, 2020 10:05 AM
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 lunch here.

Dr. William J. Schmidt - K9HZ J68HZ

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, but it would seem to me that if an FET
linear amplifier running from 50 V or higher  is considerably cleaner than
one running from 12 V, that, for a high end rig, a simple step-up switching
supply could solve the problem.  But, that obviously adds to the cost so it
IS somewhat of a conundrum.

However, implementing the pre-distortion function 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 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 simply was
incorrect in his comment and it makes a difference when considering the
expanding focus by folks like Sherwood and others to clean up the bands.
When it comes to IMD, Elecraft is not one of the better players.  The fact
that that's by choice doesn't change anything.  I suspect that 95+% of K3
rigs are used in portable/emergency situations less than 5% of the time.

73,
Dave   AB7E



On 9/13/2020 7:14 PM, Wayne Burdick wrote:

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 to this
constraint.


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.


73,
Wayne
N6KR




On Sep 13, 2020, at 6:50 PM, David Gilbert  wrote:


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 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?


Thanks and Happy Trails to all.   K8JHR

__
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...@elecraft.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 pin...@erols.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 b...@wjschmidt.com


--
This email has been checked for viruses by AVG.
https://www.avg.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 lmar...@mt.net

[Elecraft] Why predistortion?

[Chuck MacCluer]

*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 obsessed with
received signal excellence, would settle for such flawed transmitted
signals. My Orion Mk II with predistortion is far cleaner even driving two
BLF188s.
__
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 

Re: [Elecraft] 630 meter operation on the K4

[Walter Underwood]

Looking at the published specs…

Frequency Range:  100 kHz - 54 MHz (VHF/UHF range to be determined*)

https://elecraft.com/products/k4-transceiver 


wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)

> On Sep 14, 2020, at 8:10 AM, Nigel Lemaire  wrote:
> 
> Wondering what capabilities the K4 will have on this (these) bands...
> 
> 73
> Nigel
> Wa6MSE
> __
> 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 

__
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 

Re: [Elecraft] Why predistortion ?

[Joe Subich, W4TV]

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 *and* then one can make
it even cleaner with pre-distortion.  If necessary, use 50V
capable finals at 50W maximum output for 12V operation and
150-200 W output when a 48V supply is available.

73,

   ... Joe, W4TV


On 2020-09-14 7:29 AM, Charlie T wrote:

Maybe I'm missing something here, but it would seem to me that if an FET linear 
amplifier running from 50 V or higher  is considerably cleaner than one running 
from 12 V, that, for a high end rig, a simple step-up switching supply could 
solve the problem.  But, that obviously adds to the cost so it IS somewhat of a 
conundrum.

However, implementing the pre-distortion function 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 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 simply was incorrect in his comment and it 
makes a difference when considering the expanding focus by folks like Sherwood and others 
to clean up the bands.  When it comes to IMD, Elecraft is not one of the better players.  
The fact that that's by choice doesn't change anything.  I suspect that 95+% of K3 rigs 
are used in portable/emergency situations less than 5% of the time.

73,
Dave   AB7E



On 9/13/2020 7:14 PM, Wayne Burdick wrote:

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 to this constraint.

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.

73,
Wayne
N6KR




On Sep 13, 2020, at 6:50 PM, David Gilbert  wrote:


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 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?

Thanks and Happy Trails to all.   K8JHR



__
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 

Re: [Elecraft] Why predistortion ?

[Dr. William J. Schmidt]

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 lunch here.

Dr. William J. Schmidt - K9HZ J68HZ 

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, but it would seem to me that if an FET
linear amplifier running from 50 V or higher  is considerably cleaner than
one running from 12 V, that, for a high end rig, a simple step-up switching
supply could solve the problem.  But, that obviously adds to the cost so it
IS somewhat of a conundrum.

However, implementing the pre-distortion function 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 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 simply was
incorrect in his comment and it makes a difference when considering the
expanding focus by folks like Sherwood and others to clean up the bands.
When it comes to IMD, Elecraft is not one of the better players.  The fact
that that's by choice doesn't change anything.  I suspect that 95+% of K3
rigs are used in portable/emergency situations less than 5% of the time.

73,
Dave   AB7E



On 9/13/2020 7:14 PM, Wayne Burdick wrote:
> 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 to this
constraint.
>
> 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.
>
> 73,
> Wayne
> N6KR
>
>
>
>> On Sep 13, 2020, at 6:50 PM, David Gilbert  wrote:
>>
>>
>> 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 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?
>>>
>>> Thanks and Happy Trails to all.   K8JHR
>> __
>> 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...@elecraft.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 pin...@erols.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 b...@wjschmidt.com 


-- 
This email has been checked for viruses by AVG.
https://www.avg.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 arch...@mail-archive.com 

Re: [Elecraft] Why predistortion ?

[Dr. William J. Schmidt]

6AU6 - 6CL6 - 6146A trio is a very and associated circuitry produces some of
the lowest distortion products when run at the right conditions (voltages,
etc).  Note at 75 watts the 6146 is in its sweet spot.


Dr. William J. Schmidt - K9HZ


email:  b...@wjschmidt.com


-Original Message-
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 on the air of any commercial amateur radio transmitters.

73, Charlie k3ICH




-Original Message-
From: elecraft-boun...@mailman.qth.net  On
Behalf Of David Gilbert
Sent: Sunday, September 13, 2020 9:51 PM
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.

Dave   AB7E


On 9/13/2020 2:32 PM, JR wrote:
> 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?
>
> Thanks and Happy Trails to all.   K8JHR

__
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 pin...@erols.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 b...@wjschmidt.com 


-- 
This email has been checked for viruses by AVG.
https://www.avg.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 arch...@mail-archive.com 

Re: [Elecraft] Why predistortion ?

[Charlie T]

Maybe I'm missing something here, but it would seem to me that if an FET linear 
amplifier running from 50 V or higher  is considerably cleaner than one running 
from 12 V, that, for a high end rig, a simple step-up switching supply could 
solve the problem.  But, that obviously adds to the cost so it IS somewhat of a 
conundrum.

However, implementing the pre-distortion function 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 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 simply was incorrect in 
his comment and it makes a difference when considering the expanding focus by 
folks like Sherwood and others to clean up the bands.  When it comes to IMD, 
Elecraft is not one of the better players.  The fact that that's by choice 
doesn't change anything.  I suspect that 95+% of K3 rigs are used in 
portable/emergency situations less than 5% of the time.

73,
Dave   AB7E



On 9/13/2020 7:14 PM, Wayne Burdick wrote:
> 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 to this 
> constraint.
>
> 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.
>
> 73,
> Wayne
> N6KR
>
>
>
>> On Sep 13, 2020, at 6:50 PM, David Gilbert  wrote:
>>
>>
>> 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 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?
>>>
>>> Thanks and Happy Trails to all.   K8JHR
>> __
>> 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...@elecraft.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 pin...@erols.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 arch...@mail-archive.com 

Re: [Elecraft] Why predistortion ?

[Charlie T]

According to Rob Sherwood, the Collins 32S-3 produces the cleanest SSB signal 
on the air of any commercial amateur radio transmitters.

73, Charlie k3ICH




-Original Message-
From: elecraft-boun...@mailman.qth.net  On 
Behalf Of David Gilbert
Sent: Sunday, September 13, 2020 9:51 PM
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.

Dave   AB7E


On 9/13/2020 2:32 PM, JR wrote:
> 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?
>
> Thanks and Happy Trails to all.   K8JHR

__
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 pin...@erols.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 arch...@mail-archive.com 

[Elecraft] 630 meter operation on the K4

[Nigel Lemaire]

Wondering what capabilities the K4 will have on this (these) bands...

73
Nigel
Wa6MSE
__
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 

Re: [Elecraft] KAT500: Fails to tune, and shows 3:1 on good antenna on 18 MHz.

[Ken Winterling]

GL!

Ken
WA2LBI





On Mon, Sep 14, 2020 at 7:53 AM Dave Cole  wrote:

> Hi ken,
> Added the dummy, no problems, so it is the antenna...  Also, given it is
> a 6BTV with the 18 meter add on, and all other bands work, it is not the
> feedline...
>
> This makes it simple to fix!  It is either a break with the laws of
> physics as we understand them today-- or a connection has come loose.
> Given there are only two connections...  I suspect it will be a simple fix.
>
> 73, and thanks,
> Dave (NK7Z)
> https://www.nk7z.net
> ARRL Volunteer Examiner
> ARRL Technical Specialist
> ARRL Asst. Director, NW Division, Technical Resources
>
> On 9/13/20 4:24 PM, Ken Winterling wrote:
> > When you have issues like this the best test is to use a known good
> > dummy load. That removes the antenna system from the equation. See what
> > happens on 18mHz when transmitting into the summy load.
> >
> > Ken
> > WA2LBI
> >
> >
> >
> >
> > On Sun, Sep 13, 2020 at 6:58 PM Dick Dievendorff  > > wrote:
> >
> > When unpowered the KAT500 is bypassed, ANT1.
> >
> > When the ATU is in mode BYP, yes, it’s bypassed.
> >
> > 73 de Dick, K6KR
> >
> >  > On Sep 13, 2020, at 15:52, Dave Cole  > > wrote:
> >  >
> >  > Hello,
> >  > My KAT500 which worked yesterday, now shows a 3:1 on 18 MHz.,
> > only. Antenna is a single feedline to a 6BTV, and an analyzer says
> > all is good at low power.  At 100 watts, all seems good.
> >  >
> >  > All other bands seem OK at high power.
> >  >
> >  > Question:  When in bypass, is the entire tuner bypassed?
> >  > Question:  When turned off is the tuner bypassed?  Which antenna
> > is default?
> >  > --
> >  > 73, and thanks,
> >  > Dave (NK7Z)
> >  > https://www.nk7z.net
> >  > ARRL Volunteer Examiner
> >  > ARRL Technical Specialist
> >  > ARRL Asst. Director, NW Division, Technical Resources
> >  > __
> >  > 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 d...@elecraft.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  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 wa2...@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 wa2...@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 arch...@mail-archive.com 

Re: [Elecraft] KAT500: Fails to tune, and shows 3:1 on good antenna on 18 MHz.

[Dave Cole]

Hi ken,
Added the dummy, no problems, so it is the antenna...  Also, given it is 
a 6BTV with the 18 meter add on, and all other bands work, it is not the 
feedline...


This makes it simple to fix!  It is either a break with the laws of 
physics as we understand them today-- or a connection has come loose. 
Given there are only two connections...  I suspect it will be a simple fix.


73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources

On 9/13/20 4:24 PM, Ken Winterling wrote:
When you have issues like this the best test is to use a known good 
dummy load. That removes the antenna system from the equation. See what 
happens on 18mHz when transmitting into the summy load.


Ken
WA2LBI




On Sun, Sep 13, 2020 at 6:58 PM Dick Dievendorff > wrote:


When unpowered the KAT500 is bypassed, ANT1.

When the ATU is in mode BYP, yes, it’s bypassed.

73 de Dick, K6KR

 > On Sep 13, 2020, at 15:52, Dave Cole mailto:d...@nk7z.net>> wrote:
 >
 > Hello,
 > My KAT500 which worked yesterday, now shows a 3:1 on 18 MHz.,
only. Antenna is a single feedline to a 6BTV, and an analyzer says
all is good at low power.  At 100 watts, all seems good.
 >
 > All other bands seem OK at high power.
 >
 > Question:  When in bypass, is the entire tuner bypassed?
 > Question:  When turned off is the tuner bypassed?  Which antenna
is default?
 > --
 > 73, and thanks,
 > Dave (NK7Z)
 > https://www.nk7z.net
 > ARRL Volunteer Examiner
 > ARRL Technical Specialist
 > ARRL Asst. Director, NW Division, Technical Resources
 > __
 > 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 d...@elecraft.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 wa2...@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 arch...@mail-archive.com