Re: [Elecraft] UPDATE KPA1500 on 160M

[Adrian]

Bill, ok on that, yes more electronic amplifiers especially use a swr 
limit to protect against the high voltages


generated at high swr. Sometimes you are better off using a robust 
manual tuner made for the job external to the amp.


High swr between a remote balun and atu at amp, will emphasis balun 
heating loss as the signal passes the feedline length many times before


totally dissipating in the coax loss & balun core,some as heat loss, and 
some as desired induced balun current to antenna radiated RF.


Ladder line back to a close-by matchbox, which can handle KV, close to 
amp, would give best power efficiency, as ladder line has minimal 
feedline loss.


I would be using a manual ext tuner with this type of antenna, also 
taking away risk of damaging the amp.




On 3/9/20 2:19 pm, K8TE wrote:

Nowhere has there been a mention of what VSWR the tuner sees, only the result
of its match which is 2.5:1.
  That means the VSWR it sees is beyond its capability to tune properly and
run full power.  This information is available on the KPA1500 panel display.
It will also state the maximum allowable power output.  What are those
values?

I suspect the VSWR is quite high and the allowable power well below 1,500
Watts.  It's likely you're expecting more power-handling capability than the
BALUN, either one, can handle.

When one writes "quickly" that is interpreted differently by all those who
read it.  Obviously, 20 to 30 seconds is not "quickly", at least to me, but
a very good indications of something overheating, but not instantly.  The
latter could lead toward a very different conclusion.

My current (pun intended) conclusion is don't run over 800 Watts on 160m!
That is about the same level you run with your other amplifier without a
failure, maybe, if you don't run it too long at that level.  I'm glad you
concluded it's an antenna system problem.

BTW, W8JI has written about this antenna and recommends an 80-20% ratio,
rather than the typical 67-33% ratio.  He has modeled it for various bands
on his web site.  I don't know why the common 67-33% values are used when
someone has shown there is a better choice.  Old habits, good and bad, die
hard.

73, Bill, K8TE



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Re: [Elecraft] my KPA1500 and 160M

[Adrian]

Please quote your online reference please regarding ferrite cores being 
a dielectric


If so then my not just use un-enammeled wire on a course wound core ? A 
dielectric is an insulator ;



 Dielectric

From Wikipedia, the free encyclopedia
Jump to navigation 
Jump to search 

Not to be confused withDielectric constant 
orDialectic 
.



A*dielectric*(or*dielectric material*) is anelectrical insulator 



I don't see any reference to ferrite cores being a dielectric online.

The molecular alignment heating method regarding dielectric loss, is not 
mentioned on any ferrite core RF heating science, that I can find.


Please read ;

Predicting Temperature Rise of Ferrite Cored Transformers George 
Orenchak TSC Ferrite International 39105 North Magnetics Boulevard 
Wadsworth, IL 60083



"Core Losses Core losses are a significant contributor to the 
temperature rise of a transformer. Hysteresis loss, eddy *current* loss 
and residual loss all contribute to the total core loss. At high flux 
densities and relatively low frequencies, hysteresis losses are usually 
dominant. Hysteresis loss is the amount the magnetization of the ferrite 
material lags the magnetizing force because of molecular friction. The 
loss of energy due to hysteresis loss is proportional to the area of the 
static or low frequency B-H loop. At high frequencies, eddy current 
losses usually dominate. Eddy *current* loss is from a varying induction 
that produces electromotive forces, which cause a current to circulate 
within a magnetic material. These eddy *currents* result in energy loss. 
Understanding the behaviour of the combined total core loss as functions 
of flux density and of frequency is most important. "



Dielectric is not mentioned.












On 3/9/20 2:15 pm, David Gilbert wrote:


If you weren't too stubborn you could find many, many online 
references to the dielectric characteristics of ferrites.  A ferite 
core absolutely IS a dielectric.  There is nothing false about what 
I've been telling you.


Dave  AB7E



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Re: [Elecraft] UPDATE KPA1500 on 160M

[K8TE]

Nowhere has there been a mention of what VSWR the tuner sees, only the result
of its match which is 2.5:1. 
 That means the VSWR it sees is beyond its capability to tune properly and
run full power.  This information is available on the KPA1500 panel display. 
It will also state the maximum allowable power output.  What are those
values?

I suspect the VSWR is quite high and the allowable power well below 1,500
Watts.  It's likely you're expecting more power-handling capability than the
BALUN, either one, can handle.

When one writes "quickly" that is interpreted differently by all those who
read it.  Obviously, 20 to 30 seconds is not "quickly", at least to me, but
a very good indications of something overheating, but not instantly.  The
latter could lead toward a very different conclusion.

My current (pun intended) conclusion is don't run over 800 Watts on 160m! 
That is about the same level you run with your other amplifier without a
failure, maybe, if you don't run it too long at that level.  I'm glad you
concluded it's an antenna system problem.

BTW, W8JI has written about this antenna and recommends an 80-20% ratio,
rather than the typical 67-33% ratio.  He has modeled it for various bands
on his web site.  I don't know why the common 67-33% values are used when
someone has shown there is a better choice.  Old habits, good and bad, die
hard.

73, Bill, K8TE



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Re: [Elecraft] my KPA1500 and 160M

[David Gilbert]

If you weren't too stubborn you could find many, many online references 
to the dielectric characteristics of ferrites.  A ferite core absolutely 
IS a dielectric.  There is nothing false about what I've been telling you.


Dave  AB7E



On 9/2/2020 9:02 PM, Adrian wrote:



Now then, whether you want to acknowledge it or not, a ferrite core 
IS a lossy dielectric and can get hot when you put a high enough RF 
voltage across it INDEPENDENT OF THE CURRENT FLOWING THROUGH THE 
WINDING AROUND THE CORE.  You can find innumerable references to the 
dielectric losses of ferrite materials if you just bother to do some 
internet searching.  This is NOT an insulation breakdown issue ... 
not at all.


A dielectric is defined as an insulator . A ferrite core is not a 
dielectric (insulator),  This is the false fact in your theory.


*Dielectric heating*, also known as*electronic heating*,*radio 
frequency heating*, and*high-frequency heating*, is the process in 
which aradio frequency 
(RF) alternating 
electric field, orradio wave 
ormicrowave 
electromagnetic radiation 
heats 
adielectric material.


It is the dielectric material being heated via molecular rotation.


A ferrite core although not a good conductor also is not a dielectric, 
and no mention of dielectric loss is attributed to its heating losses ;



https://elnamagnetics.com/wp-content/uploads/library/TSC-Ferrite-International/Predicting_Temperature_Rise_of_Ferrite_Cored_Transformers.pdf 



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Re: [Elecraft] my KPA1500 and 160M

[David Gilbert]

Like I said, you're refusing to understand the physics of dielectric 
loss in a ferrite.  The heat is caused by dielectric currents induced by 
the high RF E-field from the VSWR, not the emf caused by the current in it.


I'm done with trying to educate you.

Dave   AB7E



On 9/2/2020 8:12 PM, Adrian wrote:


You neglect to fill in the missing part where voltage is causing the 
current which is causing the heat.


The use of a magnetic core can increase the strength ofmagnetic field 
in anelectromagnetic 
coil by a factor 
of several hundred times what it would be without the core. However, 
magnetic cores have side effects which must be taken into account. 
Inalternating current 
(AC) devices they 
cause energy losses, calledcore losses 
, due tohysteresis 
andeddy *currents* 
in applications such as 
transformers and inductors. "Soft" magnetic materials with 
lowcoercivity and 
hysteresis, such assilicon steel 
, orferrite 
, are usually used in 
cores.


Sudden high swr issues at high power are caused by insulation breakdown.

The heat is directly proportional to the current producing it. You 
half the current and therefore halve the heat.


However this does not apply to voltage as current flow cannot be taken 
for granted. talking only about voltage, as voltage can in a current 
equation.


You can halve the voltage and may have little heat due to the voltage 
breakdown no longer in place.


Magnetism is created by current, Magnetism cutting a conductor 
produces current which produces heat.


Voltage only defined, never has and never will be responsible for heat 
production P =I^2 R .


*Dielectric loss*quantifies adielectric material 
's inherent 
dissipation of electromagnetic energy (e.g. heat).^[1] 
 It can be 
parameterized in terms of either the*loss angle*/δ/or the 
corresponding*loss tangent*tan /δ/. Both refer to thephasor 
in thecomplex plane 
whose real and imaginary 
parts are theresistive 
(lossy) component 
of an electromagnetic field and itsreactive 
(lossless) 
counterpart


It is the *current* induced by this electromagnetic field, not 
cancelled by back emf, that causes heat.



On 3/9/20 12:25 pm, David Gilbert wrote:



OK ... I'm going to make this simple for you.  Picture a material 
(like a capacitor) with a lossy dielectric, and then apply a high RF 
voltage across it.  The dielectric passes a current as the result of 
the voltage, and the lossiness of the dielectric generates heat. With 
a lot of voltage the heat generated can be considerable.


Now then, whether you want to acknowledge it or not, a ferrite core 
IS a lossy dielectric and can get hot when you put a high enough RF 
voltage across it INDEPENDENT OF THE CURRENT FLOWING THROUGH THE 
WINDING AROUND THE CORE.  You can find innumerable references to the 
dielectric losses of ferrite materials if you just bother to do some 
internet searching.  This is NOT an insulation breakdown issue ... 
not at all.


All of this can happen as soon as power is applied to the system 
containing the ferrite.  Certainly the rate of temperature rise will 
be dependent upon how much voltage is applied, the frequency of it, 
and the dielectric loss characteristics of the particular ferrite, 
but VSWR is the voltage we're talking about here and that becomes 
relevant immediately upon application of power.


I suspect that you will dig in your heels and continue to dispute 
this basic physics, but at least I hope others here will understand 
things better than you do.


Dave   AB7E



On 9/2/2020 5:52 PM, Adrian wrote:
I say that your response is completely false and you are missing 
basic electricity facts. The high voltage becomes an issue when 
insulation breaks down, and then *current *starts


to flow through the fault path converting to emf & heat directly and 
via induced current resulting ;  P = E X I*. *Without the current 
the heat does not occur, it is basic physics, and


the heat is directly proportional to the current. Voltage can exist 
without current, but current cannot exist without voltage. Heat 
produced is directly proportional to the current whether


it be in the intentional circuit path, or fault path caused by high 
voltage insulation breakdown..




In addition, your statement that only current 

Re: [Elecraft] my KPA1500 and 160M

[Adrian]

Now then, whether you want to acknowledge it or not, a ferrite core IS 
a lossy dielectric and can get hot when you put a high enough RF 
voltage across it INDEPENDENT OF THE CURRENT FLOWING THROUGH THE 
WINDING AROUND THE CORE.  You can find innumerable references to the 
dielectric losses of ferrite materials if you just bother to do some 
internet searching.  This is NOT an insulation breakdown issue ... not 
at all.


A dielectric is defined as an insulator . A ferrite core is not a 
dielectric (insulator),  This is the false fact in your theory.


*Dielectric heating*, also known as*electronic heating*,*radio frequency 
heating*, and*high-frequency heating*, is the process in which aradio 
frequency (RF) 
alternating electric field, orradio wave 
ormicrowave 
electromagnetic radiation 
heats 
adielectric material.


It is the dielectric material being heated via molecular rotation.


A ferrite core although not a good conductor also is not a dielectric, 
and no mention of dielectric loss is attributed to its heating losses ;



https://elnamagnetics.com/wp-content/uploads/library/TSC-Ferrite-International/Predicting_Temperature_Rise_of_Ferrite_Cored_Transformers.pdf

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Re: [Elecraft] my KPA1500 and 160M

[Adrian]

You neglect to fill in the missing part where voltage is causing the 
current which is causing the heat.


The use of a magnetic core can increase the strength ofmagnetic field 
in anelectromagnetic coil 
by a factor of 
several hundred times what it would be without the core. However, 
magnetic cores have side effects which must be taken into account. 
Inalternating current 
(AC) devices they 
cause energy losses, calledcore losses 
, due tohysteresis 
andeddy *currents* 
in applications such as 
transformers and inductors. "Soft" magnetic materials with lowcoercivity 
and hysteresis, such 
assilicon steel , orferrite 
, are usually used in cores.


Sudden high swr issues at high power are caused by insulation breakdown.

The heat is directly proportional to the current producing it. You half 
the current and therefore halve the heat.


However this does not apply to voltage as current flow cannot be taken 
for granted. talking only about voltage, as voltage can in a current 
equation.


You can halve the voltage and may have little heat due to the voltage 
breakdown no longer in place.


Magnetism is created by current, Magnetism cutting a conductor produces 
current which produces heat.


Voltage only defined, never has and never will be responsible for heat 
production P =I^2 R .


*Dielectric loss*quantifies adielectric material 
's inherent 
dissipation of electromagnetic energy (e.g. heat).^[1] 
 It can be 
parameterized in terms of either the*loss angle*/δ/or the 
corresponding*loss tangent*tan /δ/. Both refer to thephasor 
in thecomplex plane 
whose real and imaginary 
parts are theresistive 
(lossy) component 
of an electromagnetic field and itsreactive 
(lossless) 
counterpart


It is the *current* induced by this electromagnetic field, not cancelled 
by back emf, that causes heat.



On 3/9/20 12:25 pm, David Gilbert wrote:



OK ... I'm going to make this simple for you.  Picture a material 
(like a capacitor) with a lossy dielectric, and then apply a high RF 
voltage across it.  The dielectric passes a current as the result of 
the voltage, and the lossiness of the dielectric generates heat. With 
a lot of voltage the heat generated can be considerable.


Now then, whether you want to acknowledge it or not, a ferrite core IS 
a lossy dielectric and can get hot when you put a high enough RF 
voltage across it INDEPENDENT OF THE CURRENT FLOWING THROUGH THE 
WINDING AROUND THE CORE.  You can find innumerable references to the 
dielectric losses of ferrite materials if you just bother to do some 
internet searching.  This is NOT an insulation breakdown issue ... not 
at all.


All of this can happen as soon as power is applied to the system 
containing the ferrite.  Certainly the rate of temperature rise will 
be dependent upon how much voltage is applied, the frequency of it, 
and the dielectric loss characteristics of the particular ferrite, but 
VSWR is the voltage we're talking about here and that becomes relevant 
immediately upon application of power.


I suspect that you will dig in your heels and continue to dispute this 
basic physics, but at least I hope others here will understand things 
better than you do.


Dave   AB7E



On 9/2/2020 5:52 PM, Adrian wrote:
I say that your response is completely false and you are missing 
basic electricity facts. The high voltage becomes an issue when 
insulation breaks down, and then *current *starts


to flow through the fault path converting to emf & heat directly and 
via induced current resulting ;  P = E X I*. *Without the current the 
heat does not occur, it is basic physics, and


the heat is directly proportional to the current. Voltage can exist 
without current, but current cannot exist without voltage. Heat 
produced is directly proportional to the current whether


it be in the intentional circuit path, or fault path caused by high 
voltage insulation breakdown..




In addition, your statement that only current in the balun circuit 
can produce heat is completely false.  High voltage RF can create 
major core heating due to dielectric losses in the ferrite core 
independent of the magnitude of current flow in the tuning circuit. 
Several discussions on the TowerTalk reflector have pointed this out 
over the years for 

Re: [Elecraft] [Bulk] The KSYN3A synth will always be available as a K3 upgrade

[Bill Coleman]

Well, I guess now there is an end date. I’m glad I purchased the two I needed 
last November.

> On Oct 1, 2015, at 2:54 PM, Wayne Burdick  wrote:
> 
> Hi all,
> 
> Just to put an end to any unfounded rumors: The KSYN3A will always be 
> available for K3 upgrades. We use the same synth module in the K3S, and there 
> is no end date.
> 
> 73,
> Wayne
> N6KR
> 
> 
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Bill Coleman, AA4LR, PP-ASELMail: aa...@arrl.net
Web: http://boringhamradiopart.blogspot.com
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901

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Re: [Elecraft] UPDATE KPA1500 on 160M

[Adrian]

Yes I have seen that, very good point, and I was also thinking about the 
lmr400 length earlier in the thread.


I felt that Ronnie may not warm to that idea, so did not mention it.

It is a bit of hit and miss sometimes with that solution, but once 
there, your done.



On 3/9/20 11:41 am, James Bennett via Elecraft wrote:

Ronnie,

I’m kinda late to this dance, but did want to toss in my thoughts. I assume you 
are running a length of beefy coax from the back of the KPA1500 to the balun. I 
do the same with my KPA500/KAT500. About 10 feet of 9913 coax to the Balun 
Designs box, then 110 feet of 600 ohm line to the antenna feed point. I 
initially had a very ugly SWR on 20 meters that the KAT500 balked at; the other 
bands were fine. Changing the length of the coax between the tuner and the 
balun cured the problem - I went from 20 feet (a convenient piece of coax I had 
lying around) to 10 feet. If you’ve got some other lengths of coax available, 
you might want to try switching them in / out - might be easier than chopping 
the ladder line.

73, Jim / W6JHB



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Re: [Elecraft] UPDATE KPA1500 on 160M

[Adrian]

Ok on that. I have good success with true OCF (not windom) antennas and 
Balun Designs 4:1 current baluns in the past.


These days I just use apex high delta loops with direct feed via a 
lmr240 multi-wound toroid choke at feedpoint for great results.


Bottom corner fed (vertically polarised), so feed-line length and losses 
are kept minimal . I find this type of antenna very quiet,


and neighbour friendly in all respects.


It would have been interesting to see how a 4116 performed on yours.


On 3/9/20 11:37 am, w5...@comcast.net wrote:
4114T was the BD Balun model #.  I'm not putting down there product at 
all. When strictly using the ATU in the K3 it matched wonderfully.    
The fly in the buttermilk was when the KPA1500 was thrown into the mix.


Ronnie


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Re: [Elecraft] my KPA1500 and 160M

[David Gilbert]

OK ... I'm going to make this simple for you.  Picture a material (like 
a capacitor) with a lossy dielectric, and then apply a high RF voltage 
across it.  The dielectric passes a current as the result of the 
voltage, and the lossiness of the dielectric generates heat. With a lot 
of voltage the heat generated can be considerable.


Now then, whether you want to acknowledge it or not, a ferrite core IS a 
lossy dielectric and can get hot when you put a high enough RF voltage 
across it INDEPENDENT OF THE CURRENT FLOWING THROUGH THE WINDING AROUND 
THE CORE.  You can find innumerable references to the dielectric losses 
of ferrite materials if you just bother to do some internet searching.  
This is NOT an insulation breakdown issue ... not at all.


All of this can happen as soon as power is applied to the system 
containing the ferrite.  Certainly the rate of temperature rise will be 
dependent upon how much voltage is applied, the frequency of it, and the 
dielectric loss characteristics of the particular ferrite, but VSWR is 
the voltage we're talking about here and that becomes relevant 
immediately upon application of power.


I suspect that you will dig in your heels and continue to dispute this 
basic physics, but at least I hope others here will understand things 
better than you do.


Dave   AB7E



On 9/2/2020 5:52 PM, Adrian wrote:
I say that your response is completely false and you are missing basic 
electricity facts. The high voltage becomes an issue when insulation 
breaks down, and then *current *starts


to flow through the fault path converting to emf & heat directly and 
via induced current resulting ;  P = E X I*. *Without the current the 
heat does not occur, it is basic physics, and


the heat is directly proportional to the current. Voltage can exist 
without current, but current cannot exist without voltage. Heat 
produced is directly proportional to the current whether


it be in the intentional circuit path, or fault path caused by high 
voltage insulation breakdown..




In addition, your statement that only current in the balun circuit 
can produce heat is completely false.  High voltage RF can create 
major core heating due to dielectric losses in the ferrite core 
independent of the magnitude of current flow in the tuning circuit. 
Several discussions on the TowerTalk reflector have pointed this out 
over the years for baluns and common mode chokes in ham radio 
applications.


Dave   AB7E



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Re: [Elecraft] UPDATE KPA1500 on 160M

[James Bennett via Elecraft]

Ronnie,

I’m kinda late to this dance, but did want to toss in my thoughts. I assume you 
are running a length of beefy coax from the back of the KPA1500 to the balun. I 
do the same with my KPA500/KAT500. About 10 feet of 9913 coax to the Balun 
Designs box, then 110 feet of 600 ohm line to the antenna feed point. I 
initially had a very ugly SWR on 20 meters that the KAT500 balked at; the other 
bands were fine. Changing the length of the coax between the tuner and the 
balun cured the problem - I went from 20 feet (a convenient piece of coax I had 
lying around) to 10 feet. If you’ve got some other lengths of coax available, 
you might want to try switching them in / out - might be easier than chopping 
the ladder line.

73, Jim / W6JHB



> On Sep 2, 2020, at 6:06 PM, Jim Miller  wrote:
> 
> Have you measured the impedance presented to the amplifier with an antenna 
> analyzer?
> 
> Jim ab3cv 
> 
> On Sep 2, 2020, at 9:03 PM, Adrian  > wrote:
> 
> Ronnie, well done. Moving to a different ratio balun is a smart obvious move 
> towards obtaining a better match,
> 
> especially at higher power maintaining insulation specs required.
> 
> From curiosity what was the model number of the BD 4:1 balun you had 
> initially please ?
> 
> 
>> On 3/9/20 10:03 am, Ronnie Hull wrote:
>> The original thread has gone off on some tangents. I truly appreciate all 
>> the suggestions.
>> 
>> I seem to have cured the problem!
>> 
>> ORIGINAL ISSUE was using a new W7FG 160m doublet with 600 ohm true ladder 
>> line. The ladder line was hooked to a Balun Design 4:1 ( as recommended by 
>> the seller of the antenna). The antenna would be matched great in 160M by 
>> the internal ATU in the K3 but with the KPA1500 inline it all went north 
>> really fast, resulting in the 1500 faulting out
>> 
>> Earlier today I swapped in a DX Engineering maxi core 4:1 and it worked a 
>> hell of a lot better but the KPA1500 still could not match it better than 9:1
>> 
>> Mind you this antenna matches superb on other bands with the KPA1500
>> 
>> Also the KPA1500 works great into a dummy load so I knew the issue was the 
>> antenna or part of it
>> 
>> Last I put in line a DX Engineering maxi core 6:1 and BAM... it worked!
>> The KPA1500 matches to 2.5:1 which is good enough for now.
>> 
>> Next I will experiment with the 600 ohm ladder line length. Right now I’m 
>> using 57’.  I will add 10’ tomorrow and see what shakes out and will let you 
>> fellas know
>> 
>> Thanks for all the help and suggestions!
>> 
>> Ronnie W5SUM
>> 
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Re: [Elecraft] UPDATE KPA1500 on 160M

[w5sum]

4114T was the BD Balun model #.  I'm not putting down there product at all. 
When strictly using the ATU in the K3 it matched wonderfully.The fly in 
the buttermilk was when the KPA1500 was thrown into the mix.


Ronnie

-Original Message- 
From: Adrian

Sent: Wednesday, September 02, 2020 7:59 PM
To: Ronnie Hull ; Elecraft
Subject: Re: [Elecraft] UPDATE KPA1500 on 160M

Ronnie, well done. Moving to a different ratio balun is a smart obvious
move towards obtaining a better match,

especially at higher power maintaining insulation specs required.

From curiosity what was the model number of the BD 4:1 balun you had
initially please ?


On 3/9/20 10:03 am, Ronnie Hull wrote:
The original thread has gone off on some tangents. I truly appreciate all 
the suggestions.


I seem to have cured the problem!

ORIGINAL ISSUE was using a new W7FG 160m doublet with 600 ohm true ladder 
line. The ladder line was hooked to a Balun Design 4:1 ( as recommended by 
the seller of the antenna). The antenna would be matched great in 160M by 
the internal ATU in the K3 but with the KPA1500 inline it all went north 
really fast, resulting in the 1500 faulting out


Earlier today I swapped in a DX Engineering maxi core 4:1 and it worked a 
hell of a lot better but the KPA1500 still could not match it better than 
9:1


Mind you this antenna matches superb on other bands with the KPA1500

Also the KPA1500 works great into a dummy load so I knew the issue was the 
antenna or part of it


Last I put in line a DX Engineering maxi core 6:1 and BAM... it worked!
The KPA1500 matches to 2.5:1 which is good enough for now.

Next I will experiment with the 600 ohm ladder line length. Right now I’m 
using 57’.  I will add 10’ tomorrow and see what shakes out and will let 
you fellas know


Thanks for all the help and suggestions!

Ronnie W5SUM



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Re: [Elecraft] UPDATE KPA1500 on 160M

[Jim Miller]

Have you measured the impedance presented to the amplifier with an antenna 
analyzer?

Jim ab3cv 

On Sep 2, 2020, at 9:03 PM, Adrian  wrote:

Ronnie, well done. Moving to a different ratio balun is a smart obvious move 
towards obtaining a better match,

especially at higher power maintaining insulation specs required.

From curiosity what was the model number of the BD 4:1 balun you had initially 
please ?


> On 3/9/20 10:03 am, Ronnie Hull wrote:
> The original thread has gone off on some tangents. I truly appreciate all the 
> suggestions.
> 
> I seem to have cured the problem!
> 
> ORIGINAL ISSUE was using a new W7FG 160m doublet with 600 ohm true ladder 
> line. The ladder line was hooked to a Balun Design 4:1 ( as recommended by 
> the seller of the antenna). The antenna would be matched great in 160M by the 
> internal ATU in the K3 but with the KPA1500 inline it all went north really 
> fast, resulting in the 1500 faulting out
> 
> Earlier today I swapped in a DX Engineering maxi core 4:1 and it worked a 
> hell of a lot better but the KPA1500 still could not match it better than 9:1
> 
> Mind you this antenna matches superb on other bands with the KPA1500
> 
> Also the KPA1500 works great into a dummy load so I knew the issue was the 
> antenna or part of it
> 
> Last I put in line a DX Engineering maxi core 6:1 and BAM... it worked!
> The KPA1500 matches to 2.5:1 which is good enough for now.
> 
> Next I will experiment with the 600 ohm ladder line length. Right now I’m 
> using 57’.  I will add 10’ tomorrow and see what shakes out and will let you 
> fellas know
> 
> Thanks for all the help and suggestions!
> 
> Ronnie W5SUM
> 
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Re: [Elecraft] UPDATE KPA1500 on 160M

[Adrian]

Ronnie, well done. Moving to a different ratio balun is a smart obvious 
move towards obtaining a better match,


especially at higher power maintaining insulation specs required.

From curiosity what was the model number of the BD 4:1 balun you had 
initially please ?



On 3/9/20 10:03 am, Ronnie Hull wrote:

The original thread has gone off on some tangents. I truly appreciate all the 
suggestions.

I seem to have cured the problem!

ORIGINAL ISSUE was using a new W7FG 160m doublet with 600 ohm true ladder line. 
The ladder line was hooked to a Balun Design 4:1 ( as recommended by the seller 
of the antenna). The antenna would be matched great in 160M by the internal ATU 
in the K3 but with the KPA1500 inline it all went north really fast, resulting 
in the 1500 faulting out

Earlier today I swapped in a DX Engineering maxi core 4:1 and it worked a hell 
of a lot better but the KPA1500 still could not match it better than 9:1

Mind you this antenna matches superb on other bands with the KPA1500

Also the KPA1500 works great into a dummy load so I knew the issue was the 
antenna or part of it

Last I put in line a DX Engineering maxi core 6:1 and BAM... it worked!
The KPA1500 matches to 2.5:1 which is good enough for now.

Next I will experiment with the 600 ohm ladder line length. Right now I’m using 
57’.  I will add 10’ tomorrow and see what shakes out and will let you fellas 
know

Thanks for all the help and suggestions!

Ronnie W5SUM


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Re: [Elecraft] my KPA1500 and 160M

[Adrian]

I say that your response is completely false and you are missing basic 
electricity facts. The high voltage becomes an issue when insulation 
breaks down, and then *current *starts


to flow through the fault path converting to emf & heat directly and via 
induced current resulting ;  P = E X I*. *Without the current the heat 
does not occur, it is basic physics, and


the heat is directly proportional to the current. Voltage can exist 
without current, but current cannot exist without voltage. Heat produced 
is directly proportional to the current whether


it be in the intentional circuit path, or fault path caused by high 
voltage insulation breakdown..




In addition, your statement that only current in the balun circuit can 
produce heat is completely false.  High voltage RF can create major 
core heating due to dielectric losses in the ferrite core independent 
of the magnitude of current flow in the tuning circuit. Several 
discussions on the TowerTalk reflector have pointed this out over the 
years for baluns and common mode chokes in ham radio applications.


Dave   AB7E



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[Elecraft] UPDATE KPA1500 on 160M

[Ronnie Hull]

The original thread has gone off on some tangents. I truly appreciate all the 
suggestions.

I seem to have cured the problem!

ORIGINAL ISSUE was using a new W7FG 160m doublet with 600 ohm true ladder line. 
The ladder line was hooked to a Balun Design 4:1 ( as recommended by the seller 
of the antenna). The antenna would be matched great in 160M by the internal ATU 
in the K3 but with the KPA1500 inline it all went north really fast, resulting 
in the 1500 faulting out

Earlier today I swapped in a DX Engineering maxi core 4:1 and it worked a hell 
of a lot better but the KPA1500 still could not match it better than 9:1

Mind you this antenna matches superb on other bands with the KPA1500

Also the KPA1500 works great into a dummy load so I knew the issue was the 
antenna or part of it 

Last I put in line a DX Engineering maxi core 6:1 and BAM... it worked!
The KPA1500 matches to 2.5:1 which is good enough for now.

Next I will experiment with the 600 ohm ladder line length. Right now I’m using 
57’.  I will add 10’ tomorrow and see what shakes out and will let you fellas 
know

Thanks for all the help and suggestions!

Ronnie W5SUM



Sent from my iPhone
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Re: [Elecraft] my KPA1500 and 160M

[David Gilbert]

In KP3MM's recent post he reveals that the problem doesn't occur with 
his Clipperton amp at one KW, so it appears that the problem is indeed 
within the KPA1500.  But to be clear, he never said that the problem is 
there from the start.  In his recent message he says that it takes 15 to 
30 seconds for the amp to trip.


In addition, your statement that only current in the balun circuit can 
produce heat is completely false.  High voltage RF can create major core 
heating due to dielectric losses in the ferrite core independent of the 
magnitude of current flow in the tuning circuit. Several discussions on 
the TowerTalk reflector have pointed this out over the years for baluns 
and common mode chokes in ham radio applications.


Dave   AB7E



On 9/2/2020 3:55 PM, Adrian wrote:
The problem is evident on first KPA1500 match attempt before any 
heating of the balun core is possible. It is not a core heat issue at 
all.


If it was the OP would be able to get an ok initial atu match, that 
would then deteriorate with core heat..The issue is from the get-go.


Also only current in the balun  circuit produces emf and therefore 
core heat. Voltage is only a factor in how much current flows depending


on circuit impedance, Plenty of voltage with no current = no heat.


On 3/9/20 3:25 am, David Gilbert wrote:


More likely that the ferrite core is getting hot from excessive 
VSWR.  High current could, but rarely does, heat up the coil, but 
it's high voltage which often heats up the core.  At low power (and 
therefore low VSWR voltage) it wouldn't necessarily be a problem, but 
at high power it easily could.  I know this from personal experience 
with a 160m Inverted-L that initially had a high VSWR that with high 
power heated up a MUCH better common mode choke (homebrew per K9YC 
guidelines) than the Balun Designs stuff.


73,
Dave   AB7E


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Re: [Elecraft] KPA-1500 SWR fault above 700-800 watts on 160m

[Ronnie Hull]

Update
I took the Balun designs 4:1 out of line and put a Dx Engineering maxi core 5kw 
4:1 in its place. It tunes a little better on 160 but the KPA1500 finally 
faults out and says cannot find match and shows 9:1 better than 99:1

So I put the KPA1500 straight to a 2.5kw bird dummy load and it tunes instantly 
1:1 in 160M

So this fault is with the antenna for sure

The only other Balun I have to try is a DX Engineering 6:1 which I will try in 
the morning.

Failing that I will order a 1:1 feom DX Engineering

But at least I know it’s the antenna that is causing this problem 

I’m going to also borrow a antenna analyzer tomorrow and see what gives. 
Thanks for all the suggestions!

We will whip this yet

Ronnie w5sum 

Sent from my iPhone

> On Sep 2, 2020, at 6:05 PM, Alan - G4GNX  wrote:
> 
> Ken, sorry this is rather long, but here goes...
> 
> I had a similar problem in the UK, with a OSCFD antenna, purchased from a UK 
> company. I didn't question the theory and just assembled it according to 
> instructions.
> 
> As you would expect the antenna is made from two differing lengths of 
> ruggedised, plastic coated copper wire, which is fed by a 4:1 Guanella balun, 
> rated at 400W. The balun is potted in a weatherproof box and is fed via the 
> customary PL259/SO239 connector with Mil Spec RG58 coaxial cable. About 6' 
> down from the feed point is a common mode choke (sometimes called a sleeve 
> balun) which consists of 8 ferrite inline cores, around the co-ax and held in 
> place with heat shrink sleeving and cable ties.
> 
> The rig was just the K3S/100W with internal tuner and all was well for many 
> months, mostly using 40 metres SSB. A while later, I added the KPA500/KAT500 
> combo which I ran for a couple of very short periods at 400W to test. For a 
> weekly net, I used only 200W and all seemed OK for a while, until suddenly 
> the VSWR started to increase over the period of an 'over'. Over a few weeks 
> this got more frequent and I would have to re-tune part way through an 
> 'over'. At that time, I wan't sure whether it was an antenna issue, or the 
> KPA500/KAT500, although I suspected that the KPA500 was getting too hot, so I 
> posted a question on a forum and was contacted by Jack Brindle of Elecraft, 
> who kindly looked at the KPA500 fault reports and sent me a comprehensive 
> explanation of his findings based on the figures and his experience, which 
> concluded that the antenna was almost certainly the culprit.
> 
> I ordered a new 1KW Guanella balun and some much bigger ferrites, with the 
> intention of replacing the RG58 with Westflex 103. In the meantime I 
> soldiered on with the original setup until one day all hell let loose, with 
> the KPA500 and KAT500 fault lights flashing and even the K3S got 'ticked 
> off'. At this point I switched to my HF vertical, to keep me on the air.
> 
> When I dismantled the wire antenna, I expected a balun fault, but it was 
> actually OK. On further checking, after disconnecting the co-ax from the 
> balun, the open ended co-ax showed a DC short on a test meter!
> 
> I used the Rig Expert 600 to determine exactly where the short was and it 
> turned out to be exactly where the sleeve ferrites had been, BUT there was no 
> discoloration of the outer covering, or signs of melting, so I knew it was 
> unlikely that the ferrite cores had got heated. I cut the section out of the 
> co-ax and started to take it apart. With the outer covering all removed, 
> there was still no sign of discoloration of the screen braid, but as I tried 
> to remove the braid, it was obvious that there had been considerable heating 
> as the center section of the braid has melted into the center conductor 
> insulation, and somewhere in there, it has made it right through to the 
> center conductor.
> 
> Unfortunately I haven't yet found the exact point of the short, because I 
> left the partly dismantled piece of inner co-ax on a table and one of my cats 
> seems to have run off with it! :-D
> When I eventually find it, I'll continue investigating.
> 
> In the meantime, one theory is that the common mode choke presented a high 
> impedance to RF coming back down the co-ax and this in turn produced a very 
> high voltage causing an arc between inner and outer and as the 
> characteristics changed, in turn a high current node was created, which 
> caused the heating effect. Another theory is that it is just a crappy piece 
> of cable and it just failed.
> 
> Unfortunately this is not the sort of fault that can be detected in its 
> development stage by a low power antenna analyser, it needs a fair amount of 
> power.
> 
> This long tale may just give you some clues to your possible issue on 160m 
> although on a different power scale..
> 
> 73,
> 
> Alan. G4GNX
> 
> 
> -- Original Message --
> From: "Ken Ramirez de Arellano" 
> To: elecraft@mailman.qth.net
> Sent: 02/09/2020 22:41:30
> Subject: [Elecraft] KPA-1500 SWR fault above 700-800 

[Elecraft] W2 WATT METER F/S

[Bob Gibson via Elecraft]

I have a Elecraft W2 watt meter for sale with the 200 watt coupler for $200.00

   73s Bob W5RG
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Re: [Elecraft] KPA-1500 SWR fault above 700-800 watts on 160m

[Alan - G4GNX]

Ken, sorry this is rather long, but here goes...

I had a similar problem in the UK, with a OSCFD antenna, purchased from 
a UK company. I didn't question the theory and just assembled it 
according to instructions.


As you would expect the antenna is made from two differing lengths of 
ruggedised, plastic coated copper wire, which is fed by a 4:1 Guanella 
balun, rated at 400W. The balun is potted in a weatherproof box and is 
fed via the customary PL259/SO239 connector with Mil Spec RG58 coaxial 
cable. About 6' down from the feed point is a common mode choke 
(sometimes called a sleeve balun) which consists of 8 ferrite inline 
cores, around the co-ax and held in place with heat shrink sleeving and 
cable ties.


The rig was just the K3S/100W with internal tuner and all was well for 
many months, mostly using 40 metres SSB. A while later, I added the 
KPA500/KAT500 combo which I ran for a couple of very short periods at 
400W to test. For a weekly net, I used only 200W and all seemed OK for a 
while, until suddenly the VSWR started to increase over the period of an 
'over'. Over a few weeks this got more frequent and I would have to 
re-tune part way through an 'over'. At that time, I wan't sure whether 
it was an antenna issue, or the KPA500/KAT500, although I suspected that 
the KPA500 was getting too hot, so I posted a question on a forum and 
was contacted by Jack Brindle of Elecraft, who kindly looked at the 
KPA500 fault reports and sent me a comprehensive explanation of his 
findings based on the figures and his experience, which concluded that 
the antenna was almost certainly the culprit.


I ordered a new 1KW Guanella balun and some much bigger ferrites, with 
the intention of replacing the RG58 with Westflex 103. In the meantime I 
soldiered on with the original setup until one day all hell let loose, 
with the KPA500 and KAT500 fault lights flashing and even the K3S got 
'ticked off'. At this point I switched to my HF vertical, to keep me on 
the air.


When I dismantled the wire antenna, I expected a balun fault, but it was 
actually OK. On further checking, after disconnecting the co-ax from the 
balun, the open ended co-ax showed a DC short on a test meter!


I used the Rig Expert 600 to determine exactly where the short was and 
it turned out to be exactly where the sleeve ferrites had been, BUT 
there was no discoloration of the outer covering, or signs of melting, 
so I knew it was unlikely that the ferrite cores had got heated. I cut 
the section out of the co-ax and started to take it apart. With the 
outer covering all removed, there was still no sign of discoloration of 
the screen braid, but as I tried to remove the braid, it was obvious 
that there had been considerable heating as the center section of the 
braid has melted into the center conductor insulation, and somewhere in 
there, it has made it right through to the center conductor.


Unfortunately I haven't yet found the exact point of the short, because 
I left the partly dismantled piece of inner co-ax on a table and one of 
my cats seems to have run off with it! :-D

When I eventually find it, I'll continue investigating.

In the meantime, one theory is that the common mode choke presented a 
high impedance to RF coming back down the co-ax and this in turn 
produced a very high voltage causing an arc between inner and outer and 
as the characteristics changed, in turn a high current node was created, 
which caused the heating effect. Another theory is that it is just a 
crappy piece of cable and it just failed.


Unfortunately this is not the sort of fault that can be detected in its 
development stage by a low power antenna analyser, it needs a fair 
amount of power.


This long tale may just give you some clues to your possible issue on 
160m although on a different power scale..


73,

Alan. G4GNX


-- Original Message --
From: "Ken Ramirez de Arellano" 
To: elecraft@mailman.qth.net
Sent: 02/09/2020 22:41:30
Subject: [Elecraft] KPA-1500 SWR fault above 700-800 watts on 160m


Every bit of antenna hardware ( coax, balun, insulators, etc. have been
changed out or proven good. Connections are all solid.  My KPA1500 will
transmit above 800 watts for about 15-30 seconds and then the SWR jumps up
and it faults out for high VSWR.  I can run 1500 watts on all the other
“Legacy” bands (10,15,20,40,80) with no problems. I’ve forced an STU
relearn and still the same issue. The antenna B amp is a Clipperton L and
that transmits at a KW out and I see no change in VSWR in the external
wattmeter using all of the same cabling. It’s starting to look like
something heating up in the KPA1500. Is anyone aware of a known issue for
this with the KPA1500 or a known fix? I would rather do a field repair
instead of sending to Elecraft from KP4.  TIA Ken, KP3MM
--
Ken Ramirez
KP3MM



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Re: [Elecraft] my KPA1500 and 160M

[Adrian]

The problem is evident on first KPA1500 match attempt before any heating 
of the balun core is possible. It is not a core heat issue at all.


If it was the OP would be able to get an ok initial atu match, that 
would then deteriorate with core heat..The issue is from the get-go.


Also only current in the balun  circuit produces emf and therefore core 
heat. Voltage is only a factor in how much current flows depending


on circuit impedance, Plenty of voltage with no current = no heat.


On 3/9/20 3:25 am, David Gilbert wrote:


More likely that the ferrite core is getting hot from excessive VSWR.  
High current could, but rarely does, heat up the coil, but it's high 
voltage which often heats up the core.  At low power (and therefore 
low VSWR voltage) it wouldn't necessarily be a problem, but at high 
power it easily could.  I know this from personal experience with a 
160m Inverted-L that initially had a high VSWR that with high power 
heated up a MUCH better common mode choke (homebrew per K9YC 
guidelines) than the Balun Designs stuff.


73,
Dave   AB7E




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Re: [Elecraft] KPA-1500 SWR fault above 700-800 watts on 160m

[David Gilbert]

If your Clipperton amp doesn't have the same problem then it does indeed 
point to the KPA1500.


I don't own a KPA1500, but a quick look at the online manual shows that 
the tuning unit is an L-Network.  Depending upon the load the unit is 
trying to match, an L-Network can require a very large amount of 
capacitance, especially on 160m ... which I suspect is achieved in the 
KPA1500 by switching in high power ceramic units for 160m.  I had to 
replace a couple of high power ceramic doorknob capacitors for 160m in 
my own tube amp because I had degraded them with a high VSWR per my 
earlier post about an overheating common mode choke.


Of course you might not have the same problem, but it would be one of 
the things I'd check.


73,
Dave   AB7E


On 9/2/2020 2:41 PM, Ken Ramirez de Arellano wrote:

Every bit of antenna hardware ( coax, balun, insulators, etc. have been
changed out or proven good. Connections are all solid.  My KPA1500 will
transmit above 800 watts for about 15-30 seconds and then the SWR jumps up
and it faults out for high VSWR.  I can run 1500 watts on all the other
“Legacy” bands (10,15,20,40,80) with no problems. I’ve forced an STU
relearn and still the same issue. The antenna B amp is a Clipperton L and
that transmits at a KW out and I see no change in VSWR in the external
wattmeter using all of the same cabling. It’s starting to look like
something heating up in the KPA1500. Is anyone aware of a known issue for
this with the KPA1500 or a known fix? I would rather do a field repair
instead of sending to Elecraft from KP4.  TIA Ken, KP3MM


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[Elecraft] K4 shipping

[Dauer, Edward]

Have the firm prices been set yet?  I looked but didn't see them on the web 
site.  (Yeah, I know, "If you have to ask the price . . .")

Ted, KN1CBR
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Re: [Elecraft] [K3] K3 Utility hiccup

[David Fleming via Elecraft]

Hi Don,

I just tried the same Macro (TU DON CWA) and sent it a few dozen times and it 
completes each time with no problem. Have you tried re-entering the Macro in 
another Macro slot. Can you describe what happens when it stalls? Does the 
displayed text in the text fields complete?

David, W4SMT


On Wednesday, September 2, 2020, 06:02:19 PM EDT, Don Putnick 
 wrote: 

When I use the K3 Utility Terminal tab to send CW via one of the macros
(Utility macro, not K3 macro), occasionally the macro quits part way
through. Any ideas as to what's going on? It's a really simple macro: TU
DON CWA

Configuration: K3 with latest firmware, MacBook Pro with latest version of
Catalina, K3 Utility latest version, new interface cable from Elecraft.

73 Don NA6Z
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Re: [Elecraft] K4 Shipping?

[Bill Johnson]

I was #12 for the KX3.  It was a field test.  They do more in house now rather 
for more technical engineering feedback, I would guess.

72 & 73,
Bill
K9YEQ
FT’er for K2, KX1, KX3, KXPA100,  KAT500, W2, etc. 

-Original Message-
From: elecraft-boun...@mailman.qth.net  On 
Behalf Of Nr4c
Sent: Wednesday, September 2, 2020 1:20 PM
To: N4ZR 
Cc: Elecraft List 
Subject: Re: [Elecraft] K4 Shipping?

I think they built 20-25 for Field Testors for the KX3. 

Sent from my iPhone
...nr4c. bill


> On Sep 2, 2020, at 8:22 AM, N4ZR  wrote:
> 
> Not to be a curmudgeon, but don't you suppose they built at least this many 
> for testers?
> 
> --
> 73, Pete N4ZR
> Check out the Reverse Beacon Network
> at , now
> spotting RTTY activity worldwide.
> For spots, please use your favorite
> "retail" DX cluster.
> 
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Re: [Elecraft] my KPA1500 and 160M

[Bill Johnson]

Dave, Exactly my point.  Doesn't take long to cause the core to go south.  High 
voltage is fast. 

73,
Bill
K9YEQ

-Original Message-
From: elecraft-boun...@mailman.qth.net  On 
Behalf Of David Gilbert
Sent: Wednesday, September 2, 2020 12:37 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] my KPA1500 and 160M


No ... overheating doesn't take much time at all.

As I stated in my reply to Bill, high power and high VSWR will indeed heat up a 
ferrite core device ... balun or common mode choke ... and it can do so quite 
quickly.  In my case, I had a 160m Inverted-L that I put up rather hastily for 
a contest and I didn't trim it for best match.  At
100 watts it worked fine because I could tune it at the shack, but at anything 
above 1,000 watts the ferrite core in the common mode choke would heat up and 
fault the amplifier (QRO Technologies HF-2500DX tube
amp) in less than two seconds. This happened repeatedly, and when I got serious 
and fixed the antenna for a lower VSWR everything was stable even at 1500 watts 
and even with the same choke that I luckily hadn't permanently destroyed 
(although I suspect the core had been compromised for original choking 
performance).

High VSWR is very tough on ferrite cores.

Dave   AB7E



On 9/2/2020 6:07 AM, Adrian wrote:
> Overheat is a situation taking time, and usually starts with a good 
> match, then deteriorating.
>
> In this case ; "But when I throw the KAP1500 in line, it gets all 
> pissed off, throws up and faults out.  Says SWR is 99:1 !!!"
>
> indicating an instant issue while the balun is still stone cold...
>
> The 5kw balun is not the best for your situation, but rather the 4116 
> 3KW hybrid
>
> https://www.balundesigns.com/model-4116-4-1-hybrid-balun-1-5-54mhz-3kw
> /
>
> See ;
> https://www.balundesigns.com/blog/baluns-for-multiband-antennas-fed-wi
> th-open-wire-or-ladder-line/
>
> 73
>
>
> Adrian Fewster
>
>
>
>
>
> On 2/9/20 10:12 pm, Bill Johnson wrote:
>> I would agree that the coil could overheat.  The model number is left 
>> out.  The Balun Design coil chosen may not be satisfactory for your 
>> power despite the 5KW rating.  Which Balun are you using?
>>
>> Bill
>> K9YEQ
>>
>> -Original Message-
>> From: elecraft-boun...@mailman.qth.net 
>>  On Behalf Of David Gilbert
>> Sent: Tuesday, September 1, 2020 12:28 PM
>> To: elecraft@mailman.qth.net
>> Subject: Re: [Elecraft] my KPA1500 and 160M
>>
>>
>> One distinct possibility is that the 4:1 balun is getting hot at 1500 
>> watts.  Have you tried running the KPA1500 at a lower power?
>>
>> 73,
>> Dave  AB7E
>>
>>
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[Elecraft] [K3] K3 Utility hiccup

[Don Putnick]

When I use the K3 Utility Terminal tab to send CW via one of the macros
(Utility macro, not K3 macro), occasionally the macro quits part way
through. Any ideas as to what's going on? It's a really simple macro: TU
DON CWA

Configuration: K3 with latest firmware, MacBook Pro with latest version of
Catalina, K3 Utility latest version, new interface cable from Elecraft.

73 Don NA6Z
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[Elecraft] KPA-1500 SWR fault above 700-800 watts on 160m

[Ken Ramirez de Arellano]

Every bit of antenna hardware ( coax, balun, insulators, etc. have been
changed out or proven good. Connections are all solid.  My KPA1500 will
transmit above 800 watts for about 15-30 seconds and then the SWR jumps up
and it faults out for high VSWR.  I can run 1500 watts on all the other
“Legacy” bands (10,15,20,40,80) with no problems. I’ve forced an STU
relearn and still the same issue. The antenna B amp is a Clipperton L and
that transmits at a KW out and I see no change in VSWR in the external
wattmeter using all of the same cabling. It’s starting to look like
something heating up in the KPA1500. Is anyone aware of a known issue for
this with the KPA1500 or a known fix? I would rather do a field repair
instead of sending to Elecraft from KP4.  TIA Ken, KP3MM
-- 
Ken Ramirez
KP3MM
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Re: [Elecraft] Elecraft K3s Second Receiver for sale

[Irwin Darack]

I forgot to add that I have the Sub Receiver Installation Manual

Irwin KD3TB

On Wed, Sep 2, 2020 at 3:28 PM Irwin Darack  wrote:

> I have an Elecraft K3s KRX3A, Second Receiver for Sale.
>
> It contains the
>
>- Installed in the Sub Receiver are the KRX3A Main Circuit Board,
>Mixer Board, KNB3 Board & KFL3A-2.7 Filter
>- KSYN3A  Synthesizer
>- Auxiliary DSP Circuit Board
>- Sub In Board
>- Sub Out Board
>
> I do not have the TMP Cable with the BNC Connector. This can be ordered
> from Elecraft (E850344 TMP-BNC Cable Bag).
>
> Asking $700 which includes free shipping to CON USA.
>
> Please contact me off the reflector at IDarack(at)gmail.com
>
> --
> Irwin KD3TB
>


-- 
Irwin KD3TB
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[Elecraft] Elecraft K3s Second Receiver for sale

[Irwin Darack]

I have an Elecraft K3s KRX3A, Second Receiver for Sale.

It contains the

   - Installed in the Sub Receiver are the KRX3A Main Circuit Board, Mixer
   Board, KNB3 Board & KFL3A-2.7 Filter
   - KSYN3A  Synthesizer
   - Auxiliary DSP Circuit Board
   - Sub In Board
   - Sub Out Board

I do not have the TMP Cable with the BNC Connector. This can be ordered
from Elecraft (E850344 TMP-BNC Cable Bag).

Asking $700 which includes free shipping to CON USA.

Please contact me off the reflector at IDarack(at)gmail.com

-- 
Irwin KD3TB
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Re: [Elecraft] [K2] Spurious emission in SSB

[G3WIE]

Thanks to those who replied to my post. I've now reached the point where the
level of the spurious tone is low enough. Here's what I did.

Following Don's suggestion I isolated the KSSB2 speech processor from the
balanced modulator by removing C20 and grounding the free end of R2 via a
100nF capacitor. Unfortunately the spurious was unchanged; a problem in the
speech processor could have relatively easy to fix.

I followed up on Steve's suggestion with some careful measurements on the
spacing between spurious tone and K2 carrier in LSB and USB compared with
the difference in BFO frequency for the two. This confirmed that the 4MHz
oscillator in the PIC U1 was coupling into the KSB2 output. Some years ago I
had made a modification to the KSB2 between D2 and Q2  to reduce the peak
SSB amplitude so it matched the Tune level. I reverted to the published
circuit and the level of the spurious dropped to about -45dB ref the SSB
output which suggested that this signal path is sensitive to pickup. Next I
moved C31, C40 and C43 from the top to the bottom of the PCB and constructed
a 1/2" high screen connected to their Gnd pads to shield the PIC, the
resonator and U2 from the o/p circuits (D1 ... Q2). It made a marginal
improvement, not really worthwhile but I shan't undo it

Next I increased the output to 2 watts. The spurious tone's amplitude is not
affected by the power setting so this should win me 3dB. I also lifted the
base of Q2 off the PCB and joined it to D2 and R8 with a piece of wire 1/16"
off the top of the PCB. That way the PCB track that connects to Q2's base is
no longer used in case it's picking up the 4MHz. Finally I retuned the 28MHz
BPF higher in frequency to try and move the spurious tone towards the filter
stopband. 

The spurious is now 50dB below the SSB output and I can't see how to make
any further improvement. There are other spurious outputs at that level so
there's little to be gained in any case. I don't believe I have found the
main mechanism for the coupling but as they say "sometimes good is good
enough"

73

Chris G3WIE




--
Sent from: http://elecraft.365791.n2.nabble.com/
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Re: [Elecraft] my KPA1500 and 160M

[Jim Brown]

On 9/2/2020 10:36 AM, David Gilbert wrote:

High VSWR is very tough on ferrite cores.


Yes. My Choke Cookbook is for matched loads at the point of insertion, 
and the first place for a choke should ALWAYS be at the feedpoint.


There should be one of these chokes (NOT Balun Designs or Palomar) aty 
the feedpoint of EVERY antenna.


http://k9yc.com/2018Cookbook.pdf

Fundamental concepts in k9yc.com/RFI-Ham.pdf

This material was added to the ARRL Handbook and/or Antenna Book around 
2010, and the Cookbook updated with the most recent version of each book.


73, Jim K9YC
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[Elecraft] K3 FS - Reduced!

[Mike Murray]

*Now reduced to move - $1,050 + shipping!*
Working on downsizing and selling my K3.  $1,650 plus shipping.  Prefer
pickup but could meet within 100 miles.

K3/100-F1 K3 100W Xcvr. (Factory assembled) Serial #3746
KAT3-F   1 K3 ATU
KXV3A1 K3 RX Ant, IF Out & Xvrtr Int
KRX3  1 K3 2nd RX
KFL3A-400  1 K3 400 Hz, 8 pole filter  (Main RX)
KFL3A-2.8K  2K3 2.8 kHz, 8 pole filter (Main/Sub RX)
"Y-Box" by N6TV  15 pin parallel DE15 splitter and breakout box

73,
Mike - W0AG
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Re: [Elecraft] K4 Shipping?

[Nr4c]

I think they built 20-25 for Field Testors for the KX3. 

Sent from my iPhone
...nr4c. bill


> On Sep 2, 2020, at 8:22 AM, N4ZR  wrote:
> 
> Not to be a curmudgeon, but don't you suppose they built at least this many 
> for testers?
> 
> -- 
> 73, Pete N4ZR
> Check out the Reverse Beacon Network
> at , now
> spotting RTTY activity worldwide.
> For spots, please use your favorite
> "retail" DX cluster.
> 
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Re: [Elecraft] my KPA1500 and 160M

[David Gilbert]

No ... overheating doesn't take much time at all.

As I stated in my reply to Bill, high power and high VSWR will indeed 
heat up a ferrite core device ... balun or common mode choke ... and it 
can do so quite quickly.  In my case, I had a 160m Inverted-L that I put 
up rather hastily for a contest and I didn't trim it for best match.  At 
100 watts it worked fine because I could tune it at the shack, but at 
anything above 1,000 watts the ferrite core in the common mode choke 
would heat up and fault the amplifier (QRO Technologies HF-2500DX tube 
amp) in less than two seconds. This happened repeatedly, and when I got 
serious and fixed the antenna for a lower VSWR everything was stable 
even at 1500 watts and even with the same choke that I luckily hadn't 
permanently destroyed (although I suspect the core had been compromised 
for original choking performance).


High VSWR is very tough on ferrite cores.

Dave   AB7E



On 9/2/2020 6:07 AM, Adrian wrote:
Overheat is a situation taking time, and usually starts with a good 
match, then deteriorating.


In this case ; "But when I throw the KAP1500 in line, it gets all 
pissed off, throws up and faults out.  Says SWR is 99:1 !!!"


indicating an instant issue while the balun is still stone cold...

The 5kw balun is not the best for your situation, but rather the 4116 
3KW hybrid


https://www.balundesigns.com/model-4116-4-1-hybrid-balun-1-5-54mhz-3kw/

See ; 
https://www.balundesigns.com/blog/baluns-for-multiband-antennas-fed-with-open-wire-or-ladder-line/


73


Adrian Fewster





On 2/9/20 10:12 pm, Bill Johnson wrote:
I would agree that the coil could overheat.  The model number is left 
out.  The Balun Design coil chosen may not be satisfactory for your 
power despite the 5KW rating.  Which Balun are you using?


Bill
K9YEQ

-Original Message-
From: elecraft-boun...@mailman.qth.net 
 On Behalf Of David Gilbert

Sent: Tuesday, September 1, 2020 12:28 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] my KPA1500 and 160M


One distinct possibility is that the 4:1 balun is getting hot at 1500 
watts.  Have you tried running the KPA1500 at a lower power?


73,
Dave  AB7E



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Re: [Elecraft] my KPA1500 and 160M

[David Gilbert]

More likely that the ferrite core is getting hot from excessive VSWR.  
High current could, but rarely does, heat up the coil, but it's high 
voltage which often heats up the core.  At low power (and therefore low 
VSWR voltage) it wouldn't necessarily be a problem, but at high power it 
easily could.  I know this from personal experience with a 160m 
Inverted-L that initially had a high VSWR that with high power heated up 
a MUCH better common mode choke (homebrew per K9YC guidelines) than the 
Balun Designs stuff.


73,
Dave   AB7E


On 9/2/2020 5:12 AM, Bill Johnson wrote:

I would agree that the coil could overheat.  The model number is left out.  The 
Balun Design coil chosen may not be satisfactory for your power despite the 5KW 
rating.  Which Balun are you using?

Bill
K9YEQ

-Original Message-
From: elecraft-boun...@mailman.qth.net  On 
Behalf Of David Gilbert
Sent: Tuesday, September 1, 2020 12:28 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] my KPA1500 and 160M


One distinct possibility is that the 4:1 balun is getting hot at 1500 watts.  
Have you tried running the KPA1500 at a lower power?

73,
Dave  AB7E



On 9/1/2020 9:36 AM, w5...@comcast.net wrote:

This morning I put up a W7FG true ladder line 160M doublet.   Upon
testing, the K3 internal atu does great, matches at 1.3:1.  But when I
throw the KAP1500 in line, it gets all pissed off, throws up and
faults out.  Says SWR is 99:1 !!!

The Antenna:  The Apex is at 50'.  It is in a inverted Vee config,
with both ends approx 20' off the ground.   I'm using 59' of the 600
ohm true ladder line to a Balun Designs 5KW 4:1 Balun. This is fed
with 22' of Wilson LMR400

Both the K3 internal atu, AND the KPA1500 internal atu get a great
match on 80M, 1.2:1   with no issues.

Honestly, most of the work on 160M is FT8 running 20 watts or less, so
just using the K3 to get a successful match on 160M is fine

I just wonder why the KAP1500 doesn't like the same antenna the K3 likes.

Any ideas here fellers?

thanks and 73

73 and GL OM DE w5sum

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Re: [Elecraft] K3s Internal noise on 160 meters

[Kurt Holbrook]

Good Morning,

I'm experiencing internal noise on my K3s. It is not quite 1 year old. I have 
disconnected everything from the radio and operating off of a battery and the 
problem is still there. The preamp is off. It doesn't matter if antenna one or 
two is selected but if the rx antenna is selected the noise goes away. The rx 
antenna is connected to the bnc. The noise sounds buzzy if that makes any sense 
and is gone by the time I tune up to the bottom of 80 meters.  Any help/ advice 
is greatly appreciated.


Regards,

Kurt Holbrook, KU7RT 

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[Elecraft] 2 different 144MHz transveters and CAT selection

[w4sc]

Why not use the command  “BN $” ??

This is a GET/SEL command, and has VFO select options.  Reference Programmers 
manual.

“BN 16”  selects XVERTER 1
“BN 17”  selects XVERTER 2

73 de Ben W4SC



Sent from Mail for Windows 10

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Re: [Elecraft] my KPA1500 and 160M

[Adrian]

Overheat is a situation taking time, and usually starts with a good 
match, then deteriorating.


In this case ; "But when I throw the KAP1500 in line, it gets all pissed 
off, throws up and faults out.  Says SWR is 99:1 !!!"


indicating an instant issue while the balun is still stone cold...

The 5kw balun is not the best for your situation, but rather the 4116 
3KW hybrid


https://www.balundesigns.com/model-4116-4-1-hybrid-balun-1-5-54mhz-3kw/

See ; 
https://www.balundesigns.com/blog/baluns-for-multiband-antennas-fed-with-open-wire-or-ladder-line/


73


Adrian Fewster





On 2/9/20 10:12 pm, Bill Johnson wrote:

I would agree that the coil could overheat.  The model number is left out.  The 
Balun Design coil chosen may not be satisfactory for your power despite the 5KW 
rating.  Which Balun are you using?

Bill
K9YEQ

-Original Message-
From: elecraft-boun...@mailman.qth.net  On 
Behalf Of David Gilbert
Sent: Tuesday, September 1, 2020 12:28 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] my KPA1500 and 160M


One distinct possibility is that the 4:1 balun is getting hot at 1500 watts.  
Have you tried running the KPA1500 at a lower power?

73,
Dave  AB7E



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[Elecraft] 2 different 144MHz transveters and CAT selection

[Conrad PA5Y]

I have an unusual situation in that I have 2 different 2m transverters attached 
to my K3S.

One system is a dual channel ME2T-XP and uses the SUB RX, this is only used for 
EME and it designated XV1.

The second is used on tropo/terrestrial DX and contests and is an ME2T-ProII, 
this is XV2.

If I use WSJT-X and use CAT I have a problem in that a CAT selection for 144MHz 
always chooses XV1 which is not what I want at all most of the time. There are 
gain and LO offset configurations that mean that using a switch in the IF is 
not ideal.

Currently my solution is to set the RF frequency for XV1 to 70 MHz temporarily 
which always confuses me when I want to go on 2m EME. What would be ideal would 
be some way of setting the CAT XV priority from the front panel. I think that 
this must be a firmware update, its an easy one but of course would be low down 
the list.

Something of a luxury problem I know.

Maybe there is another way or something that I did not think of?

Regards

Conrad PA5Y


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[Elecraft] K3 HAS BEEN SOLD

[Bob Gibson via Elecraft]

Thanks
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Re: [Elecraft] my KPA1500 and 160M

[Bill Johnson]

I would agree that the coil could overheat.  The model number is left out.  The 
Balun Design coil chosen may not be satisfactory for your power despite the 5KW 
rating.  Which Balun are you using?

Bill
K9YEQ

-Original Message-
From: elecraft-boun...@mailman.qth.net  On 
Behalf Of David Gilbert
Sent: Tuesday, September 1, 2020 12:28 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] my KPA1500 and 160M


One distinct possibility is that the 4:1 balun is getting hot at 1500 watts.  
Have you tried running the KPA1500 at a lower power?

73,
Dave  AB7E



On 9/1/2020 9:36 AM, w5...@comcast.net wrote:
> This morning I put up a W7FG true ladder line 160M doublet.   Upon 
> testing, the K3 internal atu does great, matches at 1.3:1.  But when I 
> throw the KAP1500 in line, it gets all pissed off, throws up and 
> faults out.  Says SWR is 99:1 !!!
>
> The Antenna:  The Apex is at 50'.  It is in a inverted Vee config, 
> with both ends approx 20' off the ground.   I'm using 59' of the 600 
> ohm true ladder line to a Balun Designs 5KW 4:1 Balun. This is fed 
> with 22' of Wilson LMR400
>
> Both the K3 internal atu, AND the KPA1500 internal atu get a great 
> match on 80M, 1.2:1   with no issues.
>
> Honestly, most of the work on 160M is FT8 running 20 watts or less, so 
> just using the K3 to get a successful match on 160M is fine
>
> I just wonder why the KAP1500 doesn't like the same antenna the K3 likes.
>
> Any ideas here fellers?
>
> thanks and 73
>
> 73 and GL OM DE w5sum

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[Elecraft] K4 Shipping?

[N4ZR]

Not to be a curmudgeon, but don't you suppose they built at least this 
many for testers?


--
73, Pete N4ZR
Check out the Reverse Beacon Network
at , now
spotting RTTY activity worldwide.
For spots, please use your favorite
"retail" DX cluster.

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Re: [Elecraft] my KPA1500 and 160M

[CUTTER DAVID via Elecraft]

Perhaps it's more to do with the common mode impedance that these 
transformers/choke present.  Is the 4:1 a true Guanella or a Ruthroff or ? 

David G3UNA

> On 02 September 2020 at 00:27 Rick NK7I  wrote:
> 
> 
> If you model it accurately, you see that a 4:1 transformer will cause most 
> (other than 160M) to have a closer match; while on a few the 1:1 device will 
> work better. 
> 
> If convenient, try each.  They each offer (dis)advantages. 
> 
> Rick NK7I
> 
> Email spiel Czech corruptions happen
> 
> > On Sep 1, 2020, at 3:26 PM, Steve Hall <99sun...@gmail.com> wrote:
> > 
> >  Additionally I find a 1:1 current balun
> > provides a better match than a 4:1.
> > __
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