OT: J and -31 mix toroids

[Julius Fazekas n2wn]

I know there are several folks here who could answer this questions.

I'm looking to improve my current chokes for my 160 and 80 Tx antennas. I was planning on going with -43 material, but after reading thought -J and/or -31 mixes might be a better solution.

The 31 mix seems a bit more difficult to find "cheep". J material is a bit more common on the excess sites. Would I notice a difference?

Currently, the 160 antenna is a Tee Vertical. 80 is a dipole, but looking at adding a Delta Loop now that I cleared out some brush...

Thanks in advance...

73,
Julius

[Jack Smith-6]

You might wish to experiment with Steward mix 35 or 40 toroids. Mix 35
has a relative permeability of 5000 and mix 40 is 10,000. Fair-Rite's 31
material has a relative permeability of 1500.

Digikey carries several sizes of toroid cores in mix 35 and 40 at
moderate price. Search DigiKey's web site for 35T or 40T to see what
they have available. For example, a 1 inch OD core is $1.19 in single
lot quantities. Smaller cores, 0.54 inch OD, are 23 cents each in single
lot.

Steward's 35 and 40 material are MnZn ferrites and will have dimensional
resonance in the HF frequency range, with the exact frequency depending
on the core dimension. I suspect that dimensional resonance won't be an
issue for a current choke at your frequency range, however. Fair-Rite
claims the 31 material, although also a MnZn ferrite, does not have
dimensional resonance. Type 43 is a NiZn ferrite and does not have
dimensional resonance in the HF frequency band.


Jack K8ZOA



Julius Fazekas n2wn wrote:

> I know there are several folks here who could answer this questions.
>
> I'm looking to improve my current chokes for my 160 and 80 Tx antennas. I was planning on going with -43 material, but after reading thought -J and/or -31 mixes might be a better solution.
>
> The 31 mix seems a bit more difficult to find "cheep". J material is a bit more common on the excess sites. Would I notice a difference?
>
> Currently, the 160 antenna is a Tee Vertical. 80 is a dipole, but looking at adding a Delta Loop now that I cleared out some brush...
>
> Thanks in advance...
>
> 73,
> Julius
>
>
> -----
> Julius Fazekas
> N2WN
>
> Tennessee Contest Group
> http://www.k4ro.net/tcg/index.html
>
> Tennessee QSO Party
> http://www.tnqp.org/
>
> Elecraft K2/100 #4455
> Elecraft K3/100 #366
>  

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[Jack Smith-6]

I should also mention that Mouser carries some Fair-Rite mix 31 cores.
They are in the catalog at Fair-Rite --
http://www.mouser.com/catalog/637/917.pdf is the current catalog page.

Jack K8ZOA


Julius Fazekas n2wn wrote:

> I know there are several folks here who could answer this questions.
>
> I'm looking to improve my current chokes for my 160 and 80 Tx antennas. I was planning on going with -43 material, but after reading thought -J and/or -31 mixes might be a better solution.
>
> The 31 mix seems a bit more difficult to find "cheep". J material is a bit more common on the excess sites. Would I notice a difference?
>
> Currently, the 160 antenna is a Tee Vertical. 80 is a dipole, but looking at adding a Delta Loop now that I cleared out some brush...
>
> Thanks in advance...
>
> 73,
> Julius
>
>
> -----
> Julius Fazekas
> N2WN
>
> Tennessee Contest Group
> http://www.k4ro.net/tcg/index.html
>
> Tennessee QSO Party
> http://www.tnqp.org/
>
> Elecraft K2/100 #4455
> Elecraft K3/100 #366
>  

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[David Cutter]

Subject: Re: [Elecraft] OT: J and -31 mix toroids

> You might wish to experiment with Steward mix 35 or 40 toroids. Mix 35
> has a relative permeability of 5000 and mix 40 is 10,000. Fair-Rite's 31
> material has a relative permeability of 1500.
>
> Digikey carries several sizes of toroid cores in mix 35 and 40 at
> moderate price. Search DigiKey's web site for 35T or 40T to see what
> they have available. For example, a 1 inch OD core is $1.19 in single
> lot quantities. Smaller cores, 0.54 inch OD, are 23 cents each in single
> lot.
>
> Steward's 35 and 40 material are MnZn ferrites and will have dimensional
> resonance in the HF frequency range, with the exact frequency depending
> on the core dimension. I suspect that dimensional resonance won't be an
> issue for a current choke at your frequency range, however. Fair-Rite
> claims the 31 material, although also a MnZn ferrite, does not have
> dimensional resonance. Type 43 is a NiZn ferrite and does not have
> dimensional resonance in the HF frequency band.
>
>
> Jack K8ZOA
>
>

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[Jim Brown-10]

On Mon, 06 Apr 2009 17:03:50 -0400, Jack Smith wrote:

>You might wish to experiment with Steward mix 35 or 40 toroids. Mix 35
>has a relative permeability of 5000 and mix 40 is 10,000. Fair-Rite's 31
>material has a relative permeability of 1500.

Relative permeabilility varies with frequency -- it is NOT a constant
(unless you use a parallel equivalent circuit). The numbers you are
quoting are low frequency values.

>Steward's 35 and 40 material are MnZn ferrites and will have dimensional
>resonance in the HF frequency range, with the exact frequency depending
>on the core dimension. I suspect that dimensional resonance won't be an
>issue for a current choke at your frequency range, however. Fair-Rite
>claims the 31 material, although also a MnZn ferrite, does not have
>dimensional resonance.

Fair-Rite has always said that -- they said it to me six years ago when I
first convinced them to make #31 toroids!  Perhaps they said it because
they viewed it as a negative. Or perhaps they wanted to throw off their
competitors. :) But our data for multiturn chokes disproves that!  

Fair-Rite #31 DOES have a mild dimensional resonance in the 2-5 MHz
range. That is what gives the pronounced broadening of the impedance
curve when you wind enough turns to move the circuit resonance below 5
MHz!  That is, the dimensional resonance and the circuit resonance
combine to act as very low Q stagger tuned circuits, extending the
usefulness of the choke by something on the order of 3/4 octave as
compared to materials like #43. That means that a single choke on #31 can
cover 160, 80, and 40 effectively, and still be decent on 30M. With fewer
turns it can cover 80-20. And so on.

>Type 43 is a NiZn ferrite and does not have
>dimensional resonance in the HF frequency band.

In general, NiZn ferrites exhibit no measureable dimensional resonance
because it occurs at VHF, where it is damped by the loss in the core.

To answer Julius's question directly. See my "Choke Cookbook" for
specific recommendations on winding chokes for the HF bands.

http://audiosystemsgroup.com/RFI-Ham.pdf

BTW -- I just got an email from Jay Terleski, WX0B, telling me that he is
now stocking #31 toroids, bought out Fair-Rite's stock (900 pieces), and
has more on order. He didn't quote prices. Jay also told me that he is
now using #31 material for the high power transmitting chokes that he
builds.

I suggest that you ask for a quote on at least 20 pieces. As active as
you are, you'll put them to good use in a few months!

73,

Jim Brown K9YC


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[Julius Fazekas n2wn]

Thanks to all for the replies... Didn't quite get an answer to the -J versus -31, but still useful.

Jim, ask for a quote from whom? WX0B or Fair-Rite?

Cheers,
Julius

Jim Brown-10 wrote

On Mon, 06 Apr 2009 17:03:50 -0400, Jack Smith wrote:

>You might wish to experiment with Steward mix 35 or 40 toroids. Mix 35
>has a relative permeability of 5000 and mix 40 is 10,000. Fair-Rite's 31
>material has a relative permeability of 1500.

Relative permeabilility varies with frequency -- it is NOT a constant
(unless you use a parallel equivalent circuit). The numbers you are
quoting are low frequency values.

>Steward's 35 and 40 material are MnZn ferrites and will have dimensional
>resonance in the HF frequency range, with the exact frequency depending
>on the core dimension. I suspect that dimensional resonance won't be an
>issue for a current choke at your frequency range, however. Fair-Rite
>claims the 31 material, although also a MnZn ferrite, does not have
>dimensional resonance.

Fair-Rite has always said that -- they said it to me six years ago when I
first convinced them to make #31 toroids!  Perhaps they said it because
they viewed it as a negative. Or perhaps they wanted to throw off their
competitors. :) But our data for multiturn chokes disproves that!  

Fair-Rite #31 DOES have a mild dimensional resonance in the 2-5 MHz
range. That is what gives the pronounced broadening of the impedance
curve when you wind enough turns to move the circuit resonance below 5
MHz!  That is, the dimensional resonance and the circuit resonance
combine to act as very low Q stagger tuned circuits, extending the
usefulness of the choke by something on the order of 3/4 octave as
compared to materials like #43. That means that a single choke on #31 can
cover 160, 80, and 40 effectively, and still be decent on 30M. With fewer
turns it can cover 80-20. And so on.

>Type 43 is a NiZn ferrite and does not have
>dimensional resonance in the HF frequency band.

In general, NiZn ferrites exhibit no measureable dimensional resonance
because it occurs at VHF, where it is damped by the loss in the core.

To answer Julius's question directly. See my "Choke Cookbook" for
specific recommendations on winding chokes for the HF bands.

http://audiosystemsgroup.com/RFI-Ham.pdf

BTW -- I just got an email from Jay Terleski, WX0B, telling me that he is
now stocking #31 toroids, bought out Fair-Rite's stock (900 pieces), and
has more on order. He didn't quote prices. Jay also told me that he is
now using #31 material for the high power transmitting chokes that he
builds.

I suggest that you ask for a quote on at least 20 pieces. As active as
you are, you'll put them to good use in a few months!

73,

Jim Brown K9YC


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[Svend Spanget]

Julius wrote:

> Jim, ask for a quote from whom? WX0B or Fair-Rite?

Perhaps http://www.arraysolutions.com/ [http://www.arraysolutions.com/] ?

73, Svend OZ7UV


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[Julius Fazekas n2wn]

Hi Svend,

They don't list them, and I suspect the ones they purchased are for their Balun/Unun products. I'm going to contact Fair Rite directly...


Julius Fazekas
N2WN

Tennessee Contest Group
http://www.k4ro.net/tcg/index.html

Tennessee QSO Party: Sunday, 6 Sept 2009
http://www.tnqp.org/

Elecraft K2/100 #4455
Elecraft K3/100 #366


--- On Tue, 4/7/09, Svend Spanget <[hidden email]> wrote:

> From: Svend Spanget <[hidden email]>
> Subject: Re: [Elecraft] OT: J and -31 mix toroids
> To: "Julius Fazekas n2wn" <[hidden email]>
> Cc: [hidden email]
> Date: Tuesday, April 7, 2009, 9:24 AM
>
>
>
>  
>  
> #yiv926258770 pre {
> white-space:pre-wrap;word-wrap:break-word;}
>
>
>
>  
>
>
> Julius wrote:
>
> > Jim, ask for a quote from
> whom? WX0B or Fair-Rite?
>
> Perhaps http://www.arraysolutions.com/ ?
>
> 73, Svend OZ7UV
>
>
>
>
>
> ____________________________________________________________
>
> TDC Bredbånd for 0 kr.
> - Spar 695 kr. Se http://tdc.dk/freemailtilbud/
>
> Denne mail er sendt via Mail på TDC Online
> - Læs mere om TDC's mailtjeneste på
> http://mail.tdconline.dk/
> ____________________________________________________________
>
>
>
>  
>
>

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[Chuck - AE4CW]

Fair-Rite has a quite high minimum order value, several hundred dollars as I recall.  OTOH Mouser stocks most of the 31 material you would likely find useful including the 2.4 inch toroids and the monster snap-on.  The Fair-Rite web site has all the technical info you will need to cross-reference to the correct part on Mouser.

Chuck, AE4CW

Julius Fazekas n2wn wrote

Hi Svend,

They don't list them, and I suspect the ones they purchased are for their Balun/Unun products. I'm going to contact Fair Rite directly...


Julius Fazekas
N2WN

Tennessee Contest Group
http://www.k4ro.net/tcg/index.html

Tennessee QSO Party: Sunday, 6 Sept 2009
http://www.tnqp.org/

Elecraft K2/100 #4455
Elecraft K3/100 #366


--- On Tue, 4/7/09, Svend Spanget <[e-mail]> wrote:

> From: Svend Spanget <[e-mail]>
> Subject: Re: [Elecraft] OT: J and -31 mix toroids
> To: "Julius Fazekas n2wn" <[e-mail]>
> Cc: [e-mail]
> Date: Tuesday, April 7, 2009, 9:24 AM
>
>
>
>  
>  
> #yiv926258770 pre {
> white-space:pre-wrap;word-wrap:break-word;}
>
>
>
>  
>
>
> Julius wrote:
>
> > Jim, ask for a quote from
> whom? WX0B or Fair-Rite?
>
> Perhaps http://www.arraysolutions.com/ ?
>
> 73, Svend OZ7UV
>
>
>
>
>
> ____________________________________________________________
>
> TDC Bredbånd for 0 kr.
> - Spar 695 kr. Se http://tdc.dk/freemailtilbud/
>
> Denne mail er sendt via Mail på TDC Online
> - Læs mere om TDC's mailtjeneste på
> http://mail.tdconline.dk/
> ____________________________________________________________
>
>
>
>  
>
>
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[Julius Fazekas n2wn]

Hi Chuck,

It really helps if one knows the proper name for an item. In this case, toroid ain't it ;o) It's considered a bead. Not sure what the difference is, other than maybe thickness?

The part in question is stocked by Mouser: http://www.mouser.com/Search/ProductDetail.aspx?qs=P8bU7i9nNAWMk1EJQzshLg%3D%3D

It's reasonably priced too.

Fair Rite was helpful on the phone too.

Array Solutions also stocks the part.

Thanks for all the help and the space. I see it's a pretty common question once I found the part number...

Happy building all!

Julius

Chuck - AE4CW wrote

Fair-Rite has a quite high minimum order value, several hundred dollars as I recall.  OTOH Mouser stocks most of the 31 material you would likely find useful including the 2.4 inch toroids and the monster snap-on.  The Fair-Rite web site has all the technical info you will need to cross-reference to the correct part on Mouser.

Chuck, AE4CW

Julius Fazekas n2wn wrote

Hi Svend,

They don't list them, and I suspect the ones they purchased are for their Balun/Unun products. I'm going to contact Fair Rite directly...


Julius Fazekas
N2WN

Tennessee Contest Group
http://www.k4ro.net/tcg/index.html

Tennessee QSO Party: Sunday, 6 Sept 2009
http://www.tnqp.org/

Elecraft K2/100 #4455
Elecraft K3/100 #366


--- On Tue, 4/7/09, Svend Spanget <[e-mail]> wrote:

> From: Svend Spanget <[e-mail]>
> Subject: Re: [Elecraft] OT: J and -31 mix toroids
> To: "Julius Fazekas n2wn" <[e-mail]>
> Cc: [e-mail]
> Date: Tuesday, April 7, 2009, 9:24 AM
>
>
>
>  
>  
> #yiv926258770 pre {
> white-space:pre-wrap;word-wrap:break-word;}
>
>
>
>  
>
>
> Julius wrote:
>
> > Jim, ask for a quote from
> whom? WX0B or Fair-Rite?
>
> Perhaps http://www.arraysolutions.com/ ?
>
> 73, Svend OZ7UV
>
>
>
>
>
> ____________________________________________________________
>
> TDC Bredbånd for 0 kr.
> - Spar 695 kr. Se http://tdc.dk/freemailtilbud/
>
> Denne mail er sendt via Mail på TDC Online
> - Læs mere om TDC's mailtjeneste på
> http://mail.tdconline.dk/
> ____________________________________________________________
>
>
>
>  
>
>
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[Mike Scott-7]

>Fair-Rite has a quite high minimum order value, several hundred dollars as
>I recall.  OTOH Mouser stocks most of the 31 material you would likely find
>useful including the 2.4 inch toroids and the monster snap-on.  The
Fair->Rite web site has all the technical info you will need to
cross-reference >to the correct part on Mouser.

Mouser unit cost is also quite high. I joined forces with a local ham friend
and we purchased our mix 31 toroids and the biggest clamp on at Lodestone
Pacific http://www.lodestonepacific.com/

You might see if you can get some friends to go in with you and save some
money. We purchased in quantities of 20 each and they were quite happy to
deal with us, fast and courteous. I don't know if we had requested a smaller
quantity if they would be so willing. They are a distributor not a retail
house.

You have to know exactly what you want so know the Fair-Rite catalog number.
The Fair-Rite catalog is on the Lodestone Pacific site.

The 2.4 inch toroid is part number 2631803802

The biggest clamp on number is 0431177081, This is a substantial clamp on
and is quite useful. It can handle 1 inch cable but is really good for
example for passing RG8X through it 7 or so times to create a really high
impedance common mode choke at your antenna feed point or elsewhere.

For shopping comparison purposes here is what we paid in January of this
year:

--2.4 inch toroid (mix 31): $5.46 each, quantity 20

--Biggest clamp on (Round Cable Snap-it, mix 31): $9.39 each, quantity 20.

Tax was zero and shipping was $7.60 for entire lot.

Mike Scott - AE6WA
Tarzana, CA (DM04 / near LA)
NAQCC 3535
K3-100 #508 / KX1  #1311



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[Jim Brown-10]

On Tue, 7 Apr 2009 05:37:40 -0700 (PDT), Julius Fazekas n2wn wrote:

>Jim, ask for a quote from whom? WX0B or Fair-Rite?

For small and medium quantities, WX0B. For large quantity ($500-$1,000
min order, buy only in box quantities), Fair-Rite or other
distributions listed on their website and in Appendix One of my
tutorial.

73,

Jim K9YC


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[w0mu]

I think Allied or some of the others in your article will sell in smaller
quantities.  Make sure you know what you are ordering.  Maybe WX0B buys
enough to get a better discount.


CC Packet Cluster W0MU-1
W0MU.NET or  67.40.148.194

"A slip of the foot you may soon recover, but a slip of the tongue you may
never get over." Ben Franklin



-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Jim Brown
Sent: Wednesday, April 08, 2009 9:50 AM
To: [hidden email]
Subject: Re: [Elecraft] OT: J and -31 mix toroids

On Tue, 7 Apr 2009 05:37:40 -0700 (PDT), Julius Fazekas n2wn wrote:

>Jim, ask for a quote from whom? WX0B or Fair-Rite?

For small and medium quantities, WX0B. For large quantity ($500-$1,000 min
order, buy only in box quantities), Fair-Rite or other distributions listed
on their website and in Appendix One of my tutorial.

73,

Jim K9YC


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[Jim Brown-10]

On Tue, 7 Apr 2009 09:23:15 -0700 (PDT), Julius Fazekas n2wn wrote:

> I see it's a pretty common question once I found the part number...

I don't get it. I went to a LOT of trouble to write that tutorial, then
post a link to it in response to questions like this, tell people where
to look, and still questions like this. The Fair-Rite part numbers are
listed with graphs of the performance of these parts in the tutorial
where they are discussed in the text, and REPEATED in Appendix One, with
detailed advice about where to buy them and how to buy them.  

Everything you need to know to wind chokes for the bands you want to
operate is in the Choke Cookbook.

73,

Jim Brown K9YC




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[Julius Fazekas n2wn]

Mike and all,

Loadstone quoted $5.4506 each for quantities of 1 to 249 pieces. They do have a minimum order of $50. Very nice on the phone.

I'm ordering for our Tennessee Contest Group, so we will exceed the minimum by a little bit ;o)

This should kill the last of the garbage on my 160M antenna.

Cheers,
Julius

Mike Scott-7 wrote

>Fair-Rite has a quite high minimum order value, several hundred dollars as
>I recall.  OTOH Mouser stocks most of the 31 material you would likely find
>useful including the 2.4 inch toroids and the monster snap-on.  The
Fair->Rite web site has all the technical info you will need to
cross-reference >to the correct part on Mouser.

Mouser unit cost is also quite high. I joined forces with a local ham friend
and we purchased our mix 31 toroids and the biggest clamp on at Lodestone
Pacific http://www.lodestonepacific.com/

You might see if you can get some friends to go in with you and save some
money. We purchased in quantities of 20 each and they were quite happy to
deal with us, fast and courteous. I don't know if we had requested a smaller
quantity if they would be so willing. They are a distributor not a retail
house.

You have to know exactly what you want so know the Fair-Rite catalog number.
The Fair-Rite catalog is on the Lodestone Pacific site.

The 2.4 inch toroid is part number 2631803802

The biggest clamp on number is 0431177081, This is a substantial clamp on
and is quite useful. It can handle 1 inch cable but is really good for
example for passing RG8X through it 7 or so times to create a really high
impedance common mode choke at your antenna feed point or elsewhere.

For shopping comparison purposes here is what we paid in January of this
year:

--2.4 inch toroid (mix 31): $5.46 each, quantity 20

--Biggest clamp on (Round Cable Snap-it, mix 31): $9.39 each, quantity 20.

Tax was zero and shipping was $7.60 for entire lot.

Mike Scott - AE6WA
Tarzana, CA (DM04 / near LA)
NAQCC 3535
K3-100 #508 / KX1  #1311



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[Jim Brown-10]

On Tue, 7 Apr 2009 14:01:30 -0700, Mike Scott wrote:

Very good advice, Mike. Other good distributors are listed in my tutorial and
on the Fair-Rite website. The ham distributors whose names you recognize are
the WORST choices -- very expensive, very high markups. I'm hoping that WX0B
(Array Solutions) will do better. Jay said that he DOES want to sell these
parts to hams, and he has a great reputation in the ham community.

>For shopping comparison purposes here is what we paid in January of this
>year:

>--2.4 inch toroid (mix 31): $5.46 each, quantity 20

>--Biggest clamp on (Round Cable Snap-it, mix 31): $9.39 each, quantity 20.

>Tax was zero and shipping was $7.60 for entire lot.

This is the kind of pricing you should expect from a distributor for these
parts -- BUT you've got to buy in quantity to get these prices.

73,

Jim Brown K9YC


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[Adam Koczarski-2]

> -----Original Message-----
> From: [hidden email] [mailto:elecraft-
> [hidden email]] On Behalf Of Jim Brown
> Sent: Wednesday, April 08, 2009 8:57 AM
> To: [hidden email]
> Subject: Re: [Elecraft] OT: J and -31 mix toroids
>
> On Tue, 7 Apr 2009 09:23:15 -0700 (PDT), Julius Fazekas n2wn wrote:
>
> > I see it's a pretty common question once I found the part number...
>
> I don't get it. I went to a LOT of trouble to write that tutorial, then
> post a link to it in response to questions like this, tell people where
> to look, and still questions like this.

Well, I for one appreciate the write up! I called and ordered a box of them
from one of the distributors and got a great deal!

Thanks!

Adam - K3ARK




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[Julius Fazekas n2wn]

Pretty simple Jim, I'm old ;o)

I probably have three copies of this tutorial printed in various locations, but never where I need it when I have time to search.

On the other hand, I do recall the size and material of the item in question. Usually that's an easy way to search for surplus parts, uber cheap. It doesn't always work.

Fair-Rite's number system is not particularly user friendly either.

We could discuss spam ;o)

Cheers,
Julius
 
Julius Fazekas
N2WN

Tennessee Contest Group
http://www.k4ro.net/tcg/index.html

Tennessee QSO Party: Sunday, 6 Sept 2009
http://www.tnqp.org/

Elecraft K2/100 #4455
Elecraft K3/100 #366
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