Elecraft

[OT] WWV Time Transmissions

Classic

List

Threaded

44 messages Options

123

Elecraft mailing list

Re: my KPA1500 and 160M

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 <[hidden email]> 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 <[hidden email]> wrote:
> >
> > Additionally I find a 1:1 current balun
> > provides a better match than a 4:1.
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> > Message delivered to [hidden email]
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

Bill K9YEQ

Re: my KPA1500 and 160M

In reply to this post by David Gilbert-2

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: [hidden email] <[hidden email]> On Behalf Of David Gilbert
Sent: Tuesday, September 1, 2020 12:28 PM
To: [hidden email]
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, [hidden email] 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

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email]
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Adrian-3

Re: my KPA1500 and 160M

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:

David Gilbert-2

Re: my KPA1500 and 160M

In reply to this post by Bill K9YEQ

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: [hidden email] <[hidden email]> On Behalf Of David Gilbert
> Sent: Tuesday, September 1, 2020 12:28 PM
> To: [hidden email]
> 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, [hidden email] 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
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email]

David Gilbert-2

Re: my KPA1500 and 160M

In reply to this post by Adrian-3

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: [hidden email]
>> <[hidden email]> On Behalf Of David Gilbert
>> Sent: Tuesday, September 1, 2020 12:28 PM
>> To: [hidden email]
>> 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
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

Jim Brown-10

Re: my KPA1500 and 160M

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
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Bill K9YEQ

Re: my KPA1500 and 160M

In reply to this post by David Gilbert-2

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: [hidden email] <[hidden email]> On Behalf Of David Gilbert
Sent: Wednesday, September 2, 2020 12:37 PM
To: [hidden email]
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: [hidden email]
>> <[hidden email]> On Behalf Of David Gilbert
>> Sent: Tuesday, September 1, 2020 12:28 PM
>> To: [hidden email]
>> 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
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net Please help support this email
> list: http://www.qsl.net/donate.html Message delivered to
> [hidden email]

Adrian-3

Re: my KPA1500 and 160M

In reply to this post by David Gilbert-2

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
>
>
>

David Gilbert-2

Re: my KPA1500 and 160M

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

Adrian-3

Re: my KPA1500 and 160M

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
>
>

David Gilbert-2

Re: my KPA1500 and 160M

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
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

Adrian-3

Re: my KPA1500 and 160M

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
<https://en.wikipedia.org/wiki/Magnetic_field>in anelectromagnetic coil
<https://en.wikipedia.org/wiki/Electromagnetic_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
<https://en.wikipedia.org/wiki/Alternating_current>(AC) devices they
cause energy losses, calledcore losses
<https://en.wikipedia.org/wiki/Core_losses>, due tohysteresis
<https://en.wikipedia.org/wiki/Hysteresis_loss>andeddy *currents*
<https://en.wikipedia.org/wiki/Eddy_current>in applications such as
transformers and inductors. "Soft" magnetic materials with lowcoercivity
<https://en.wikipedia.org/wiki/Magnetic_coercivity>and hysteresis, such
assilicon steel <https://en.wikipedia.org/wiki/Silicon_steel>, orferrite
<https://en.wikipedia.org/wiki/Ferrite_(magnet)>, 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
<https://en.wikipedia.org/wiki/Dielectric_material>'s inherent
dissipation of electromagnetic energy (e.g. heat).^[1]
<https://en.wikipedia.org/wiki/Dielectric_loss#cite_note-1> It can be
parameterized in terms of either the*loss angle*/δ/or the
corresponding*loss tangent*tan /δ/. Both refer to thephasor
<https://en.wikipedia.org/wiki/Phasor>in thecomplex plane
<https://en.wikipedia.org/wiki/Complex_plane>whose real and imaginary
parts are theresistive
<https://en.wikipedia.org/wiki/Electrical_resistance>(lossy) component
of an electromagnetic field and itsreactive
<https://en.wikipedia.org/wiki/Reactance_(electronics)>(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 baluns and common mode chokes in ham radio
>>> applications.
>>>
>>> Dave AB7E
>>>
>>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

Adrian-3

Re: my KPA1500 and 160M

In reply to this post by David Gilbert-2

> 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 <https://en.wikipedia.org/wiki/Radio_frequency>(RF)
alternating electric field, orradio wave
<https://en.wikipedia.org/wiki/Radio_wave>ormicrowave
<https://en.wikipedia.org/wiki/Microwave>electromagnetic radiation
<https://en.wikipedia.org/wiki/Electromagnetic_radiation>heats
adielectric <https://en.wikipedia.org/wiki/Dielectric>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

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

David Gilbert-2

Re: my KPA1500 and 160M

In reply to this post by Adrian-3

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
> <https://en.wikipedia.org/wiki/Magnetic_field>in anelectromagnetic
> coil <https://en.wikipedia.org/wiki/Electromagnetic_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
> <https://en.wikipedia.org/wiki/Alternating_current>(AC) devices they
> cause energy losses, calledcore losses
> <https://en.wikipedia.org/wiki/Core_losses>, due tohysteresis
> <https://en.wikipedia.org/wiki/Hysteresis_loss>andeddy *currents*
> <https://en.wikipedia.org/wiki/Eddy_current>in applications such as
> transformers and inductors. "Soft" magnetic materials with
> lowcoercivity <https://en.wikipedia.org/wiki/Magnetic_coercivity>and
> hysteresis, such assilicon steel
> <https://en.wikipedia.org/wiki/Silicon_steel>, orferrite
> <https://en.wikipedia.org/wiki/Ferrite_(magnet)>, 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
> <https://en.wikipedia.org/wiki/Dielectric_material>'s inherent
> dissipation of electromagnetic energy (e.g. heat).^[1]
> <https://en.wikipedia.org/wiki/Dielectric_loss#cite_note-1> It can be
> parameterized in terms of either the*loss angle*/δ/or the
> corresponding*loss tangent*tan /δ/. Both refer to thephasor
> <https://en.wikipedia.org/wiki/Phasor>in thecomplex plane
> <https://en.wikipedia.org/wiki/Complex_plane>whose real and imaginary
> parts are theresistive
> <https://en.wikipedia.org/wiki/Electrical_resistance>(lossy) component
> of an electromagnetic field and itsreactive
> <https://en.wikipedia.org/wiki/Reactance_(electronics)>(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 baluns and common mode chokes in ham radio
>>>> applications.
>>>>
>>>> Dave AB7E
>>>>
>>>>
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:[hidden email]
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>> Message delivered to [hidden email]
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]

David Gilbert-2

Re: my KPA1500 and 160M

In reply to this post by Adrian-3

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
> <https://en.wikipedia.org/wiki/Radio_frequency>(RF) alternating
> electric field, orradio wave
> <https://en.wikipedia.org/wiki/Radio_wave>ormicrowave
> <https://en.wikipedia.org/wiki/Microwave>electromagnetic radiation
> <https://en.wikipedia.org/wiki/Electromagnetic_radiation>heats
> adielectric <https://en.wikipedia.org/wiki/Dielectric>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
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

Adrian-3

Re: my KPA1500 and 160M

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
<https://en.wikipedia.org/wiki/Dielectric#mw-head>Jump to search
<https://en.wikipedia.org/wiki/Dielectric#searchInput>
Not to be confused withDielectric constant
<https://en.wikipedia.org/wiki/Dielectric_constant>orDialectic
<https://en.wikipedia.org/wiki/Dialectic>.

A*dielectric*(or*dielectric material*) is anelectrical insulator
<https://en.wikipedia.org/wiki/Insulator_(electricity)>

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
>
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Adrian-3

Re: my KPA1500 and 160M

That reference contradicts itself by its ceramic refence point to ;

A *ceramic* is any of the various hard, brittle, heat-resistant and
corrosion-resistant materials made by shaping and then firing a
nonmetallic^[1] <https://en.wikipedia.org/wiki/Ceramic#cite_note-1>
mineral, such as clay, at a high temperature.^[2]
<https://en.wikipedia.org/wiki/Ceramic#cite_note-2> Common examples are
earthenware <https://en.wikipedia.org/wiki/Earthenware>, porcelain
<https://en.wikipedia.org/wiki/Porcelain>, and brick
<https://en.wikipedia.org/wiki/Brick>.

Ferrite is not a non-metallic material. I would advise the wiki to
correct it's mistake. The facts are given

by those expert on the subject that the dielectric molecular alignment
method of heating does not apply to ferrite core heat loss,

since the ferrite core being a high permeability material, already has
its molecules aligned, and therefore no realignment, with its heat

generating resistance being heat produced by the dielectric method is
happening.

You have not referred to any reference stating a ferrite core is a
dielectric.

POWER CONSIDERATIONS
(Iron Powder & Ferrite)

How large a core is needed to handle a certain amount of power? This is
a question often asked, but unfortunately there is no simple answer.

There are several factors involved such as: cross sectional area of the
core, core material, turns count, and of course the variables of applied
voltage and operating frequency.

Overheating of the coil will usually take place long before saturation
in most applications above 100 KHz. Now the question becomes "How large
a core must I have to prevent overheating at a given frequency and power
level? "

Overheating can be caused by both wire and core material losses. Wire
heating is affected by both DC and AC currents, while core heating is
affected only by the AC (induced eddy *currents*) content of the signal.
With a normal sine wave signal above 100 KHz, both the Iron Powder and
Ferrite type cores will first be affected by overheating caused by core
losses, rather than by saturation.

Nothing about dielectric heating here.

Mr Lazy

On 3/9/20 3:31 pm, David Gilbert wrote:

>
>
> If you weren't so stubborn (or lazy) you could have easily found this
> reference on Wikipedia:
>
> "A *ferrite* is a ceramic material made by mixing and firing large
> proportions of iron(III) oxide (Fe_2 O_3 , rust) blended with small
> proportions of one or more additional metallic elements, such as
> barium, manganese, nickel, and zinc."
>
> https://en.wikipedia.org/wiki/Ferrite_(magnet)
>
> Note the term "*ceramic*". In what world do you live where ceramics
> don't have dielectric properties? Ever heard of ceramic capacitors?
>
> A simple Google search for "dielectric properties of ferrites" (of
> which of course there are many varieties) turns up this sampling of
> references out of a total of approximately *1,230,000* hits:
>
> https://ieeexplore.ieee.org/abstract/document/4051871
>
> https://www.sciencedirect.com/science/article/abs/pii/S0925838809002084
>
> https://pdfs.semanticscholar.org/9298/4f47d7c6060357c3f8c39bc142911960c5cf.pdf
> (scroll down to page 58)
>
> https://aip.scitation.org/doi/abs/10.1063/1.4792494?journalCode=jap
>
> http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.416.6977&rep=rep1&type=pdf
>
> https://iopscience.iop.org/article/10.1143/JJAP.10.1520/meta
>
> https://ieeexplore.ieee.org/document/4051871
>
> https://www.hindawi.com/journals/jnp/2016/4709687/
>
> http://www.bjp-bg.com/papers/bjp2018_1_044-053.pdf
>
> http://www.ijera.com/papers/Vol7_issue2/Part-5/I0702054348.pdf
>
> http://chalcogen.ro/265_Farid.pdf
>
> Every one of those links talks about the dielectric properties of
> ferrites.
>
> Dave AB7E
>
>
>
> On 9/2/2020 9:47 PM, Adrian wrote:
>>
>> 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
>> <https://en.wikipedia.org/wiki/Dielectric#mw-head>Jump to search
>> <https://en.wikipedia.org/wiki/Dielectric#searchInput>
>> Not to be confused withDielectric constant
>> <https://en.wikipedia.org/wiki/Dielectric_constant>orDialectic
>> <https://en.wikipedia.org/wiki/Dialectic>.
>>
>>
>> A*dielectric*(or*dielectric material*) is anelectrical insulator
>> <https://en.wikipedia.org/wiki/Insulator_(electricity)>
>>
>> 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
>>>
>>>
>

Adrian-3

Re: my KPA1500 and 160M

In reply to this post by Adrian-3

Do you ever see slices of ferrite core used in capacitors, how do you
think that would work ?

I bet you won't charge that one up.Putting metal laden material between
charged poles is not a good idea.

They usually stick to using a thin non metallic insulator with good
insulation properties, otherwise known as a true dielectric.

Ferrite cores are not a dielectric

by David Gilbert ;

>
> Note the term "*ceramic*". In what world do you live where ceramics
> don't have dielectric properties? Ever heard of ceramic capacitors?
>
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Jim Brown-10

Re: my KPA1500 and 160M

In reply to this post by Adrian-3

On 9/2/2020 9:02 PM, Adrian wrote:
> A dielectric is defined as an insulator . A ferrite core is not a
> dielectric (insulator), This is the false fact in your theory.
You have massive gaps in your understanding of how common mode chokes
work and the properties of ferrite materials. The best technical data
refererence I know of Fair-Rite's catalog, which is online and can be
downloaded as a pdf.

https://ebiz.fair-rite.com/newfair/pdf/Fair-Rite_Catalog_17th_Edition.pdf

The fundamental properties of ferrite materials vary widely depending on
their chemical composition, commonly called "the mix," and each mix is
tailored to a specific range of applications. A table summarizing those
properties begins on page 4 in the print version, page 6 of the pdf. The
resistivity of the materials listed varies over 7 orders of magnitude,
from 50 ohm-cm to 10 exp9 ohm-cm.

My tutorial on how common mode chokes work is here.
k9yc.com/RFI-Ham.pdf
The concepts were added to the ARRL Handbook around 2011. Designs for
practical transmitting chokes are here.
http://k9yc.com/2018Cookbook.pdf

Note that these are not "baluns," a word that describes at least ten
very different physical things, but rather common mode chokes. Their
sole function is to minimize common mode current. They do not do
impedance matching. That function is provided by very different things
best called tranformer baluns, and they come in multiple forms.

Extensive research I published in a peer reviewed AES paper in 2003
found manufacturer's literature from the '50s/'60s indicating that they
understood how common mode chokes work, and after I published my work to
the ham community, an engineering manager from the CIA passed along to
me an unclassified engineering report from the US Army in the '70s that
was in agreement with all of the fundamental concepts I had published
and had developed a family of designs for field use. The only thing they
missed was the property of dimensional resonance, which I learned about
in classic reference a colleague found in the U of Chicago engineering
library. That reference, by E. C. Snelling, is cited in several of my
publications.

73, Jim K9YC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Barry Simpson

Re: my KPA1500 and 160M

In reply to this post by Adrian-3

This is an increasingly ungentlemanly debate.

I am not an engineer nor do I claim any expertise in or knowledge of the
subject under discussion.

However, after a very rapid Google search, the following website would
appear to provide some authoritative information.

Please note that I have only identified it from the subject heading and I
have not read it.

https://ieeexplore.ieee.org/document/4051871

Best regards to both of you.

Barry Simpson VK2BJ

On Thu, 3 Sep 2020 at 16:18, Adrian <[hidden email]> wrote:

>
> Do you ever see slices of ferrite core used in capacitors, how do you
> think that would work ?
>
> I bet you won't charge that one up.Putting metal laden material between
> charged poles is not a good idea.
>
> They usually stick to using a thin non metallic insulator with good
> insulation properties, otherwise known as a true dielectric.
>
>
> Ferrite cores are not a dielectric
>
>
>
> by David Gilbert ;
>
> >
> > Note the term "*ceramic*". In what world do you live where ceramics
> > don't have dielectric properties? Ever heard of ceramic capacitors?
> >
> >
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

123