Topband: Ferrite Cores

[Hugh Valentine]

K9YC touts the benefits of the 2.4" O.D. Mix #31 Core.
Anyone know a good source?
I bought a hand full from Arrow last year, now theirs are on back order.
Other sites seem pricey.

Anyone have good inexpensive(relatively) source?
Thanks
Val
P>S> The Bird-feeder needs some sprucing up and thought would try these on her.
____________________________________________________________
The #1 Worst Carb Ever?
Click to Learn #1 Carb that Kills Your Blood Sugar (Don't Eat This!)
http://thirdpartyoffers.juno.com/TGL3141/53e001595426d1597a0ast04vuc

[Tim Shoppa]

Fair-Rite 2631803802 is the Amidon FT-240-31. Available at Mouser,
Newark, Arrow, and other places. Mouser part # 623-2631803802. Mouser
says they have 1589 of them in stock :-).

I have a personal cross-ref between some Amidon and Fair-rite numbers.
Not sure if I'd get in trouble for publishing it (I remember when I
got chewed out here for suggesting Laird/Steward equivs). I don't
think it's a big secret - the Fair-Rite part numbering system for
toroids and binocular cores seems pretty transparent.

I like to use a white paint marker to put mix numbers on big cores as
I unpack them :-)

Tim N3QE


On Mon, Aug 4, 2014 at 5:54 PM, Hugh Valentine <hsvdds at juno.com> wrote:

> K9YC touts the benefits of the 2.4" O.D. Mix #31 Core.
> Anyone know a good source?
> I bought a hand full from Arrow last year, now theirs are on back order.
> Other sites seem pricey.
>
> Anyone have good inexpensive(relatively) source?
> Thanks
> Val
> P>S> The Bird-feeder needs some sprucing up and thought would try these on
> her.
> ____________________________________________________________
> The #1 Worst Carb Ever?
> Click to Learn #1 Carb that Kills Your Blood Sugar &#40;Don&#39;t Eat
> This!&#41;
> http://thirdpartyoffers.juno.com/TGL3141/53e001595426d1597a0ast04vuc
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>

[Jim Brown]

On 8/4/2014 2:54 PM, Hugh Valentine wrote:
> K9YC touts the benefits of the 2.4" O.D. Mix #31 Core.
> Anyone know a good source?

Last winter, I bought nearly 1,000 cores from Dexter Magnetics, near
Chicago. Good service. Use the part numbers in Appendix One of my
tutorial. They're an industrial vendor, don't know their minimum order.
When you call for a quote, ask what the quantity is for the next price
break.


On 8/4/2014 3:03 PM, Tim Shoppa wrote:
> Not sure if I'd get in trouble for publishing it

Why should you? Last I looked, Amidon was quite expensive.
> (I remember when I got chewed out here for suggesting Laird/Steward equivs).

Steward makes equivalents for some ferrite materials, but Fair-Rite's
#31 mix is fairly new, and last I looked, there were no equivalents. A
big part of the problem is getting good data -- Fair-Rite has some of
the best data I've ever seen for passive components, so you know what
you're getting.

73, Jim K9YC

[Bill Wichers]

I used to think amidon was expensive too, but just last week I ordered some cores from them that we're almost 30% cheaper than mouser. I was pretty surprised. It's probably worth checking prices again if you haven't recently.

-Bill

Sent from my iPad
>
> Why should you? Last I looked, Amidon was quite expensive.
>> (I remember when I got chewed out here for suggesting Laird/Steward equivs).
>
>

[Randy Lake]

The best deal I was able to find was Kreger for $5.95/25
Also found Arrow at $4.83/1 but they have 300 on backorder.

Randy N1KWF


On Mon, Aug 4, 2014 at 6:40 PM, Bill Wichers <billw at waveform.net> wrote:

> I used to think amidon was expensive too, but just last week I ordered
> some cores from them that we're almost 30% cheaper than mouser. I was
> pretty surprised. It's probably worth checking prices again if you haven't
> recently.
>
> -Bill
>
> Sent from my iPad
> >
> > Why should you? Last I looked, Amidon was quite expensive.
> >> (I remember when I got chewed out here for suggesting Laird/Steward
> equivs).
> >
> >
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>



--
Randy Lake N1KWF
73 Gunn Rd.
Keene,NH

[Carl]

Which cores were that?

Maybe they have been doing some comparisons recently since Mouser, Digi-Key,
Arrow, etc have been well advertised on many forums.

The most overpriced has always been Palomar

Carl
KM1H


----- Original Message -----
From: "Bill Wichers" <billw at waveform.net>
To: <jim at audiosystemsgroup.com>
Cc: <topband at contesting.com>
Sent: Monday, August 04, 2014 6:40 PM
Subject: Re: Topband: Ferrite Cores


>I used to think amidon was expensive too, but just last week I ordered some
>cores from them that we're almost 30% cheaper than mouser. I was pretty
>surprised. It's probably worth checking prices again if you haven't
>recently.
>
> -Bill
>
> Sent from my iPad
>>
>> Why should you? Last I looked, Amidon was quite expensive.
>>> (I remember when I got chewed out here for suggesting Laird/Steward
>>> equivs).
>>
>>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2014.0.4716 / Virus Database: 3986/7981 - Release Date: 08/04/14
>

[Bill Wichers]

FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite equivalent) was $14/ea. I was only ordering six cores so I couldn't make anyones quantity break.

Digi Key I don't think has many of the larger cores, but they have a *lot* of the smaller PCB-size stuff. I'm liking that my "regular" component suppliers are starting to carry more magnetics generally though :-)

-Bill

> -----Original Message-----
> From: Carl [mailto:km1h at jeremy.mv.com]
> Sent: Monday, August 04, 2014 10:40 PM
> To: Bill Wichers; jim at audiosystemsgroup.com
> Cc: topband at contesting.com
> Subject: Re: Topband: Ferrite Cores
>
> Which cores were that?
>
> Maybe they have been doing some comparisons recently since Mouser, Digi-
> Key, Arrow, etc have been well advertised on many forums.
>
> The most overpriced has always been Palomar
>
> Carl
> KM1H
>
>
> ----- Original Message -----
> From: "Bill Wichers" <billw at waveform.net>
> To: <jim at audiosystemsgroup.com>
> Cc: <topband at contesting.com>
> Sent: Monday, August 04, 2014 6:40 PM
> Subject: Re: Topband: Ferrite Cores
>
>
> >I used to think amidon was expensive too, but just last week I ordered
> some
> >cores from them that we're almost 30% cheaper than mouser. I was pretty
> >surprised. It's probably worth checking prices again if you haven't
> >recently.
> >
> > -Bill
> >
> > Sent from my iPad
> >>
> >> Why should you? Last I looked, Amidon was quite expensive.
> >>> (I remember when I got chewed out here for suggesting Laird/Steward
> >>> equivs).
> >>
> >>
> > _________________
> > Topband Reflector Archives - http://www.contesting.com/_topband
> >
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2014.0.4716 / Virus Database: 3986/7981 - Release Date: 08/04/14
> >

[Mike Waters]

On Tue, Aug 5, 2014 at 1:22 PM, Bill Wichers <billw at waveform.net> wrote:

> FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite equivalent)
> was $14/ea.
>

Those were the SAME Amidon cores that Greg, W9GB said were crumbly, cheap
Chinese junk and completely unusable. See my previous post.

73, Mike
www.w0btu.com

[Bill Wichers]

Well, I should have them in a few days so I?ll check them out and report back what I find. Maybe Greg just got some from a bad lot?

-Bill

From: Mike Waters [mailto:mikewate at gmail.com]
Sent: Tuesday, August 05, 2014 2:36 PM
To: Bill Wichers; topband
Subject: Re: Topband: Ferrite Cores

On Tue, Aug 5, 2014 at 1:22 PM, Bill Wichers <billw at waveform.net<mailto:billw at waveform.net>> wrote:
FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite equivalent) was $14/ea.

Those were the SAME Amidon cores that Greg, W9GB said were crumbly, cheap Chinese junk and completely unusable. See my previous post.
73, Mike
www.w0btu.com<http://www.w0btu.com>

[Mike Waters]

It's certainly possible.

You can read what he said and see photos at
http://forums.qrz.com/showthread.php?240056-Need-source-for-Cushcraft-R5-torroids&p=1882177#post1882177

73, Mike
www.w0btu.com

On Tue, Aug 5, 2014 at 1:54 PM, Bill Wichers <billw at waveform.net> wrote:

> Well, I should have them in a few days so I?ll check them out and report
> back what I find. Maybe Greg just got some from a bad lot?
>
> FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite equivalent)
> was $14/ea.
>
>
>
> Those were the SAME Amidon cores that Greg, W9GB said were crumbly, cheap
> Chinese junk and completely unusable. See my previous post.
>

[Bill Wichers]

It sounds like they weren?t properly fired from what he said about them crumbling. That, at least, is an easier thing to look for than a messed up mix. If they have poor QC on these things then I?d be concerned about the ?mix #61? not actually being mixed correctly resulting in the cores not having the correct magnetic properties. If I have some time I can put together a test setup for that and check the ones I have coming to be sure.

That post looks to be several years old so hopefully Amidon has corrected the problem, or otherwise switched suppliers.

-Bill

From: Mike Waters [mailto:mikewate at gmail.com]
Sent: Tuesday, August 05, 2014 3:01 PM
To: Bill Wichers
Cc: topband
Subject: Re: Topband: Ferrite Cores

It's certainly possible.

You can read what he said and see photos at
http://forums.qrz.com/showthread.php?240056-Need-source-for-Cushcraft-R5-torroids&p=1882177#post1882177

73, Mike
www.w0btu.com<http://www.w0btu.com>

On Tue, Aug 5, 2014 at 1:54 PM, Bill Wichers <billw at waveform.net<mailto:billw at waveform.net>> wrote:
Well, I should have them in a few days so I?ll check them out and report back what I find. Maybe Greg just got some from a bad lot?
FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite equivalent) was $14/ea.

Those were the SAME Amidon cores that Greg, W9GB said were crumbly, cheap Chinese junk and completely unusable. See my previous post.

[Bill Wichers]

My cores arrived yesterday. I haven't done any electrical testing on them yet, but mechanically they appear to be fine. They were not "crumbly" as some were concerned about. I don't think they are as high quality as the fair rite cores I've used in the past, but this is based only on aesthetics (the amidon cores I received have some striations in the faces, and will mar fingers if you rub them). I don't think they will be a problem in service.

My known-to-be fair rite cores from a previous mouser order did not show any striations in the faces of the cores, nor did anything come off on fingers when they were rubbed. They were also #31 mix though, so that might be part of it. I don't have any other #61 cores laying around to try with a "rub test".

It looks to me that amidon has either switched suppliers or their supplier has corrected the problem that was reported earlier.

-Bill

Sent from my iPad

> On Aug 5, 2014, at 3:29 PM, "Bill Wichers" <billw at waveform.net> wrote:
>
> It sounds like they weren?t properly fired from what he said about them crumbling. That, at least, is an easier thing to look for than a messed up mix. If they have poor QC on these things then I?d be concerned about the ?mix #61? not actually being mixed correctly resulting in the cores not having the correct magnetic properties. If I have some time I can put together a test setup for that and check the ones I have coming to be sure.
>
> That post looks to be several years old so hopefully Amidon has corrected the problem, or otherwise switched suppliers.
>
> -Bill
>
> From: Mike Waters [mailto:mikewate at gmail.com]
> Sent: Tuesday, August 05, 2014 3:01 PM
> To: Bill Wichers
> Cc: topband
> Subject: Re: Topband: Ferrite Cores
>
> It's certainly possible.
>
> You can read what he said and see photos at
> http://forums.qrz.com/showthread.php?240056-Need-source-for-Cushcraft-R5-torroids&p=1882177#post1882177
>
> 73, Mike
> www.w0btu.com<http://www.w0btu.com>
>
> On Tue, Aug 5, 2014 at 1:54 PM, Bill Wichers <billw at waveform.net<mailto:billw at waveform.net>> wrote:
> Well, I should have them in a few days so I?ll check them out and report back what I find. Maybe Greg just got some from a bad lot?
> FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite equivalent) was $14/ea.
>
> Those were the SAME Amidon cores that Greg, W9GB said were crumbly, cheap Chinese junk and completely unusable. See my previous post.
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband

[Jim Brown]

On 8/5/2014 11:36 AM, Mike Waters wrote:
> FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite equivalent)
> >was $14/ea.

The actual manufacturer of a 2.4-in o.d. #61 toroid IS Fair-Rite. It is
not an "equivalent," #61 material is Fair-Rite's mix. Other companies
may make a "knock-off," but the REAL part is made by Fair-Rite.

73, Jim K9YC

[Charlie]

I agree with all those points, Jim! Over the years, professionally, we
designed many Fair-Rite, cores into most of our electricity, gas and water
meter and electricity load-management products and shipped millions of
Fair-Rite products in our devices. Fair-Rite and Kreger are excellent
suppliers, and I still have many of their development kits around here.
Their products are excellent and very consistent

Lynne Frye, of Kreger, is a very helpful contact person, that I have worked
with over the years!

Have a good day!

73,
Charlie Cunningham, K4OTV



-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Jim Brown
Sent: Tuesday, August 05, 2014 3:00 PM
To: topband at contesting.com
Subject: Re: Topband: Ferrite Cores

On 8/5/2014 11:36 AM, Mike Waters wrote:
> FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite
> equivalent)
> >was $14/ea.

The actual manufacturer of a 2.4-in o.d. #61 toroid IS Fair-Rite. It is not
an "equivalent," #61 material is Fair-Rite's mix. Other companies may make a
"knock-off," but the REAL part is made by Fair-Rite.

73, Jim K9YC


_________________
Topband Reflector Archives - http://www.contesting.com/_topband


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[Ron Stordahl, AE5E via Topband]

In this discussion two different ferrite mixes are mentioned:? #31 and #61.?


From the descriptions of these on the Fair-Rite web page, it appears that 31 would be more suitable for lower frequency applications.?


Is this the case?

Ron, AE5E



On Wednesday, August 6, 2014 4:02 AM, Charlie <charlie-cunningham at nc.rr.com> wrote:



I agree with all those points, Jim! Over the years, professionally, we
designed many Fair-Rite, cores into most of our electricity, gas and water
meter and electricity load-management products and shipped millions of
Fair-Rite products in our devices.? Fair-Rite and Kreger are excellent
suppliers, and I still have many of their development kits around here.
Their products are excellent and very consistent

Lynne Frye, of Kreger, is a very helpful contact person, that I have worked
with over the years!

Have a good day!

73,
Charlie Cunningham, K4OTV



-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Jim Brown
Sent: Tuesday, August 05, 2014 3:00 PM
To: topband at contesting.com
Subject: Re: Topband: Ferrite Cores

On 8/5/2014 11:36 AM, Mike Waters wrote:
> FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite
> equivalent)
> >was $14/ea.

The actual manufacturer of a 2.4-in o.d. #61 toroid? IS Fair-Rite. It is not
an "equivalent," #61 material is Fair-Rite's mix. Other companies may make a
"knock-off," but the REAL part is made by Fair-Rite.

73, Jim K9YC


_________________
Topband Reflector Archives - http://www.contesting.com/_topband


---
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[Carl]

31 and 43 mix are the popular ones in the 2-30 MHz range for common mode
suppression; 31 wins at 160 and 80, but 43 is better in the 7-30 range.

Before 31 came along I used 43 even at 160 and observed problems went away
since they werent as bad as others experienced.

Carl
KM1H


----- Original Message -----
From: "Ron Stordahl, AE5E via Topband" <topband at contesting.com>
To: <jim at audiosystemsgroup.com>; <topband at contesting.com>
Sent: Wednesday, August 06, 2014 11:15 AM
Subject: Re: Topband: Ferrite Cores


In this discussion two different ferrite mixes are mentioned: #31 and #61.


>From the descriptions of these on the Fair-Rite web page, it appears that 31
would be more suitable for lower frequency applications.


Is this the case?

Ron, AE5E



On Wednesday, August 6, 2014 4:02 AM, Charlie <charlie-cunningham at nc.rr.com>
wrote:



I agree with all those points, Jim! Over the years, professionally, we
designed many Fair-Rite, cores into most of our electricity, gas and water
meter and electricity load-management products and shipped millions of
Fair-Rite products in our devices. Fair-Rite and Kreger are excellent
suppliers, and I still have many of their development kits around here.
Their products are excellent and very consistent

Lynne Frye, of Kreger, is a very helpful contact person, that I have worked
with over the years!

Have a good day!

73,
Charlie Cunningham, K4OTV



-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Jim Brown
Sent: Tuesday, August 05, 2014 3:00 PM
To: topband at contesting.com
Subject: Re: Topband: Ferrite Cores

On 8/5/2014 11:36 AM, Mike Waters wrote:
> FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite
> equivalent)
> >was $14/ea.

The actual manufacturer of a 2.4-in o.d. #61 toroid IS Fair-Rite. It is not
an "equivalent," #61 material is Fair-Rite's mix. Other companies may make a
"knock-off," but the REAL part is made by Fair-Rite.

73, Jim K9YC


_________________
Topband Reflector Archives - http://www.contesting.com/_topband


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_________________
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-----
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Checked by AVG - www.avg.com
Version: 2014.0.4716 / Virus Database: 3986/7988 - Release Date: 08/05/14

[Jim Brown]

On 8/6/2014 8:31 AM, Carl wrote:
> 31 and 43 mix are the popular ones in the 2-30 MHz range for common
> mode suppression; 31 wins at 160 and 80, but 43 is better in the 7-30
> range.

I would amend that only to say that #31 and #43 are roughly equivalent
in the 5-15 MHz, range, #43 is slightly better above 15 MHz. #43 is a
bit less expensive than #31, but the cost difference disappears if you
buy #31 in quantity. My last group purchase of #31 2.4-in cores was for
1,100 pieces, about two years ago. We paid about $4.

Because #31 is so much better on 80 and 160, because it is more
broadband below 15 MHz, and because it remains effective through the HF
range, I long ago made the engineering decision to buy #31 in quantity
for ham HF applications. If I were ONLY working above 80M, I would look
at pricing on #43 in the quantities I needed.

73, Jim K9YC

[Carl]

You should start selling them on here along with those balun cores.

Carl
KM1H


----- Original Message -----
From: "Jim Brown" <jim at audiosystemsgroup.com>
To: "'TopBand'" <topband at contesting.com>
Sent: Wednesday, August 06, 2014 1:10 PM
Subject: Re: Topband: Ferrite Cores


> On 8/6/2014 8:31 AM, Carl wrote:
>> 31 and 43 mix are the popular ones in the 2-30 MHz range for common
>> mode suppression; 31 wins at 160 and 80, but 43 is better in the 7-30
>> range.
>
> I would amend that only to say that #31 and #43 are roughly equivalent
> in the 5-15 MHz, range, #43 is slightly better above 15 MHz. #43 is a
> bit less expensive than #31, but the cost difference disappears if you
> buy #31 in quantity. My last group purchase of #31 2.4-in cores was for
> 1,100 pieces, about two years ago. We paid about $4.
>
> Because #31 is so much better on 80 and 160, because it is more
> broadband below 15 MHz, and because it remains effective through the HF
> range, I long ago made the engineering decision to buy #31 in quantity
> for ham HF applications. If I were ONLY working above 80M, I would look
> at pricing on #43 in the quantities I needed.
>
> 73, Jim K9YC
>
>
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2014.0.4716 / Virus Database: 3986/7988 - Release Date: 08/05/14
>

[Jim Brown]

On 8/6/2014 12:47 PM, Carl wrote:
> You should start selling them on here along with those balun cores.

I'm retired, and in giving back mode. :)

73, Jim

[Carl]

> On 8/6/2014 8:31 AM, Carl wrote:
>> 31 and 43 mix are the popular ones in the 2-30 MHz range for common mode
>> suppression; 31 wins at 160 and 80, but 43 is better in the 7-30 range.
>
> I would amend that only to say that #31 and #43 are roughly equivalent in
> the 5-15 MHz, range, #43 is slightly better above 15 MHz. #43 is a bit
> less expensive than #31, but the cost difference disappears if you buy #31
> in quantity. My last group purchase of #31 2.4-in cores was for 1,100
> pieces, about two years ago. We paid about $4.
>
> Because #31 is so much better on 80 and 160, because it is more broadband
> below 15 MHz, and because it remains effective through the HF range, I
> long ago made the engineering decision to buy #31 in quantity for ham HF
> applications. If I were ONLY working above 80M, I would look at pricing
> on #43 in the quantities I needed.
>
> 73, Jim K9YC


Im just basing it on some personal experience but havent run any lab tests.

On a 40M inverted V with apex at 55' Id been using a pigtail with 43 for
years, switching to 31, and no ferrite I couldnt hear any difference, both
worked well. I mentioned the 43 since it is much cheaper.

For 20M I used a 3 el HB monobander at 60' on another tower and the 43
seemed a hair better.

Not exactly scientific and with a wide range of mix tolerances Im not going
to worry about it, a few extra turns of coax would have sufficed.

Both antennas are part of the AM station and were easy to get to.

Since I dont run enough power to cause non linearities that isnt a concern
on TX.

Carl
KM1H

[Tim Shoppa]

#31 is a very nice mix for winding chokes especially at topband and lower
HF and for EMI suppression.

#61 is very common for HF transformers up to medium power levels.

#43 is also useful at HF transformers and chokes especially at upper HF.

#73 is a very nice mix for low band transformers but some of the testing
done shows typical transformers to be good 5kHz-50MHz:
http://www.cliftonlaboratories.com/imd_in_broadband_transformers.htm

I have been using #73 binocular cores for all sorts of things lately. A
little Fair-Rite 2873000202 core works excellently in isolated DC-to-DC
power converters at the several watt power level.



On Wed, Aug 6, 2014 at 11:15 AM, Ron Stordahl, AE5E via Topband <
topband at contesting.com> wrote:

> In this discussion two different ferrite mixes are mentioned: #31 and
> #61.
>
>
> From the descriptions of these on the Fair-Rite web page, it appears that
> 31 would be more suitable for lower frequency applications.
>
>
> Is this the case?
>
> Ron, AE5E
>
>
>
> On Wednesday, August 6, 2014 4:02 AM, Charlie <
> charlie-cunningham at nc.rr.com> wrote:
>
>
>
> I agree with all those points, Jim! Over the years, professionally, we
> designed many Fair-Rite, cores into most of our electricity, gas and water
> meter and electricity load-management products and shipped millions of
> Fair-Rite products in our devices. Fair-Rite and Kreger are excellent
> suppliers, and I still have many of their development kits around here.
> Their products are excellent and very consistent
>
> Lynne Frye, of Kreger, is a very helpful contact person, that I have worked
> with over the years!
>
> Have a good day!
>
> 73,
> Charlie Cunningham, K4OTV
>
>
>
> -----Original Message-----
> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Jim
> Brown
> Sent: Tuesday, August 05, 2014 3:00 PM
> To: topband at contesting.com
> Subject: Re: Topband: Ferrite Cores
>
> On 8/5/2014 11:36 AM, Mike Waters wrote:
> > FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite
> > equivalent)
> > >was $14/ea.
>
> The actual manufacturer of a 2.4-in o.d. #61 toroid IS Fair-Rite. It is
> not
> an "equivalent," #61 material is Fair-Rite's mix. Other companies may make
> a
> "knock-off," but the REAL part is made by Fair-Rite.
>
> 73, Jim K9YC
>
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
>
> ---
> This email is free from viruses and malware because avast! Antivirus
> protection is active.
> http://www.avast.com
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>

[Charlie]

I've mostly used 73 mix tubular and binocular Fair-Rite cores of all sorts
of common-mode chokes on coax and for matching transformers 160/80m
receiving loops and for input match to my 3-500ZG amp. Have had good results
all around I used 73 because it's what I had on hand. Fair-Rite 73 material
is really rugged and seems be very resistant to corrosion etc.

73,
Charlie, K4OTV

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Tim
Shoppa
Sent: Wednesday, August 06, 2014 12:45 PM
To: Ron Stordahl, AE5E
Cc: topband at contesting.com; jim at audiosystemsgroup.com
Subject: Re: Topband: Ferrite Cores

#31 is a very nice mix for winding chokes especially at topband and lower HF
and for EMI suppression.

#61 is very common for HF transformers up to medium power levels.

#43 is also useful at HF transformers and chokes especially at upper HF.

#73 is a very nice mix for low band transformers but some of the testing
done shows typical transformers to be good 5kHz-50MHz:
http://www.cliftonlaboratories.com/imd_in_broadband_transformers.htm

I have been using #73 binocular cores for all sorts of things lately. A
little Fair-Rite 2873000202 core works excellently in isolated DC-to-DC
power converters at the several watt power level.



On Wed, Aug 6, 2014 at 11:15 AM, Ron Stordahl, AE5E via Topband <
topband at contesting.com> wrote:

> In this discussion two different ferrite mixes are mentioned: #31 and
> #61.
>
>
> From the descriptions of these on the Fair-Rite web page, it appears
> that
> 31 would be more suitable for lower frequency applications.
>
>
> Is this the case?
>
> Ron, AE5E
>
>
>
> On Wednesday, August 6, 2014 4:02 AM, Charlie <
> charlie-cunningham at nc.rr.com> wrote:
>
>
>
> I agree with all those points, Jim! Over the years, professionally, we
> designed many Fair-Rite, cores into most of our electricity, gas and
> water meter and electricity load-management products and shipped
> millions of Fair-Rite products in our devices. Fair-Rite and Kreger
> are excellent suppliers, and I still have many of their development kits
around here.
> Their products are excellent and very consistent
>
> Lynne Frye, of Kreger, is a very helpful contact person, that I have
> worked with over the years!
>
> Have a good day!
>
> 73,
> Charlie Cunningham, K4OTV
>
>
>
> -----Original Message-----
> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Jim
> Brown
> Sent: Tuesday, August 05, 2014 3:00 PM
> To: topband at contesting.com
> Subject: Re: Topband: Ferrite Cores
>
> On 8/5/2014 11:36 AM, Mike Waters wrote:
> > FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite
> > equivalent)
> > >was $14/ea.
>
> The actual manufacturer of a 2.4-in o.d. #61 toroid IS Fair-Rite. It
> is not an "equivalent," #61 material is Fair-Rite's mix. Other
> companies may make a "knock-off," but the REAL part is made by
> Fair-Rite.
>
> 73, Jim K9YC
>
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
>
> ---
> This email is free from viruses and malware because avast! Antivirus
> protection is active.
> http://www.avast.com
>
> _________________
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> _________________
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>
_________________
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[Mike Waters]

#73 material is usable from 5 kHz to 50MHz? I thought that was a typo at
first.
I'll have to study that a little closer sometime. :-)

73, Mike
www.w0btu.com

On Wed, Aug 6, 2014 at 11:45 AM, Tim Shoppa <tshoppa at gmail.com> wrote:

> #73 is a very nice mix for low band transformers but some of the testing
> done shows typical transformers to be good 5kHz-50MHz:
> http://www.cliftonlaboratories.com/imd_in_broadband_transformers.htm
>
> I have been using #73 binocular cores for all sorts of things lately. A
> little Fair-Rite 2873000202 core works excellently in isolated DC-to-DC
> power converters at the several watt power level.
>

[Tom W8JI]

In this discussion two different ferrite mixes are mentioned: #31 and #61.


>From the descriptions of these on the Fair-Rite web page, it appears that 31
would be more suitable for lower frequency applications. >>>>

Core selection can be fairly complex in transmitting systems. I've yet to
see a case where one core mix is the be all end all for the range of things
you run into in the field. Especially at high common mode impedances.

Receiving is a completely different story, because core stresses are always
low.

73 Tom

[Charlie]

Well, I don't think there is a "one-size" or "one--mix" "fits all" preferred
solution. I've wanted to try some 31 mix cores for common-mode isolation at
80 and 160. On the other hand, some of the Fair-Rite 71 (73?) material
toroids and binocular cores provide really good performance, even at lower
frequencies, because of the lower losses and better frequency response.

I also suspect that for power handling applications ( including common-mode
suppression), the 31 mix might have some heating issues, because of the
higher losses.

BTW, I do know from experience that the Fair-Rite 71/73 etc. mix higher
frequency cores seem to be impervious to weather! I have used the tubular
cores and large binocular cores out of doors for years as common mode chokes
on RG-213 for my 5-band quad feed-line and to make quick home-brew W2DU 1:1
current baluns for vertical dipoles for. 30 and 40 meters. I've never seen
any evidence of corrosion nor have I noted any performance degradation.
I've used the binocular transformer cores to construct matching transformers
for "KAZ" terminated receiving loops for 160.80.40 and 30 m and use a
larger binocular core to match 50 ohms up to the cathode impedance of my
home-brew 3-500ZG amp, to avoid having to install a much more complex
band-switch. Works quite well 160-10m and comfortably handles everything
that my FT-1000MP delivers.

Fortunately I had a good selection of cores in my Fair-Rite developer kits
from my engineering days!

73,
Charlie, K4OTV



-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Tom W8JI
Sent: Wednesday, August 06, 2014 3:09 PM
To: Ron Stordahl, AE5E; topband at contesting.com
Subject: Re: Topband: Ferrite Cores


In this discussion two different ferrite mixes are mentioned: #31 and #61.


>From the descriptions of these on the Fair-Rite web page, it appears that 31
would be more suitable for lower frequency applications. >>>>

Core selection can be fairly complex in transmitting systems. I've yet to
see a case where one core mix is the be all end all for the range of things
you run into in the field. Especially at high common mode impedances.

Receiving is a completely different story, because core stresses are always
low.

73 Tom


_________________
Topband Reflector Archives - http://www.contesting.com/_topband


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[mstangelo]

Bill,

Mouser has the Fairrite core 2631803802 for 6.94 single lot quantities.

Mike N2MS

----- Original Message -----
From: Bill Wichers <billw at waveform.net>
To: Carl <km1h at jeremy.mv.com>, jim at audiosystemsgroup.com
Cc: topband at contesting.com
Sent: Tue, 05 Aug 2014 18:22:47 -0000 (UTC)
Subject: Re: Topband: Ferrite Cores

FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite equivalent) was $14/ea. I was only ordering six cores so I couldn't make anyones quantity break.

Digi Key I don't think has many of the larger cores, but they have a *lot* of the smaller PCB-size stuff. I'm liking that my "regular" component suppliers are starting to carry more magnetics generally though :-)

-Bill

[Bill Wichers]

I was buying fair rite #5961003801 though which are $15.79/ea in single-unit quantities from mouser (that is the usual 2.4" od toroid in #61 that is commonly used for baluns). I think one of the other posts was looking for the #31 cores.

-Bill



Sent from my iPad


On Aug 5, 2014, at 4:30 PM, "mstangelo at comcast.net<mailto:mstangelo at comcast.net>" <mstangelo at comcast.net<mailto:mstangelo at comcast.net>> wrote:

Bill,

Mouser has the Fairrite core 2631803802 for 6.94 single lot quantities.

Mike N2MS

----- Original Message -----
From: Bill Wichers <billw at waveform.net<mailto:billw at waveform.net>>
To: Carl <km1h at jeremy.mv.com<mailto:km1h at jeremy.mv.com>>, jim at audiosystemsgroup.com<mailto:jim at audiosystemsgroup.com>
Cc: topband at contesting.com<mailto:topband at contesting.com>
Sent: Tue, 05 Aug 2014 18:22:47 -0000 (UTC)
Subject: Re: Topband: Ferrite Cores

FT-240-61 cores. Amidon was $9/ea, Mouser (for the Fair Rite equivalent) was $14/ea. I was only ordering six cores so I couldn't make anyones quantity break.

Digi Key I don't think has many of the larger cores, but they have a *lot* of the smaller PCB-size stuff. I'm liking that my "regular" component suppliers are starting to carry more magnetics generally though :-)

-Bill

[Mike Waters]

I haven't bought a thing from Amidon after reading a few bad experiences on
qrz.com. Here's one:
forums.qrz.com/showthread.php?240056-Need-source-for-Cushcraft-R5-torroids
forums.qrz.com/showthread.php?301910-FT-900-putting-out-25-watts-in-SSB-with-ATU-off
Read W9GB's comments there* and then decide if you still want to buy from
them.

* "DO NOT purchase Amidon's Chinese imported cores (2009) -- too soft and
will easy break again."
"Amidon changed suppliers (supposedly to a Chinese company)..."

Maybe it was just one type of core. And maybe things have changed for the
better at Amidon. But Newark and Mouser have all the cores I need, and at
cheaper prices than Amidon, too.

73, Mike
www.w0btu.com

[wb6rse1]

Ships quickly:

http://kitsandparts.com/toroids.php

Steve WB6RSE


On Aug 4, 2014, at 2:54 PM, Hugh Valentine <hsvdds at juno.com> wrote:

K9YC touts the benefits of the 2.4" O.D. Mix #31 Core.
Anyone know a good source?
I bought a hand full from Arrow last year, now theirs are on back order.
Other sites seem pricey.

[Carl]

Hmm, $3 each more than Mouser who also is a very fast shipper, usually same
day.

Mouser Part 623-2631803802

Carl
KM1H


----- Original Message -----
From: <wb6rse1 at mac.com>
To: "Hugh Valentine" <hsvdds at juno.com>
Cc: "Top Band List List" <topband at contesting.com>
Sent: Monday, August 04, 2014 10:39 PM
Subject: Re: Topband: Ferrite Cores


> Ships quickly:
>
> http://kitsandparts.com/toroids.php
>
> Steve WB6RSE
>
>
> On Aug 4, 2014, at 2:54 PM, Hugh Valentine <hsvdds at juno.com> wrote:
>
> K9YC touts the benefits of the 2.4" O.D. Mix #31 Core.
> Anyone know a good source?
> I bought a hand full from Arrow last year, now theirs are on back order.
> Other sites seem pricey.
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2014.0.4716 / Virus Database: 3986/7981 - Release Date: 08/04/14
>

[Greg]

The Mouser part picture does not look like a FT-240-31. The referenced part
number looks like it fits over a cable.

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Carl
Sent: Tuesday, August 05, 2014 7:57 AM
To: wb6rse1 at mac.com; Hugh Valentine
Cc: Top Band List List
Subject: Re: Topband: Ferrite Cores

Hmm, $3 each more than Mouser who also is a very fast shipper, usually same
day.

Mouser Part 623-2631803802

Carl
KM1H


----- Original Message -----
From: <wb6rse1 at mac.com>
To: "Hugh Valentine" <hsvdds at juno.com>
Cc: "Top Band List List" <topband at contesting.com>
Sent: Monday, August 04, 2014 10:39 PM
Subject: Re: Topband: Ferrite Cores


> Ships quickly:
>
> http://kitsandparts.com/toroids.php
>
> Steve WB6RSE
>
>
> On Aug 4, 2014, at 2:54 PM, Hugh Valentine <hsvdds at juno.com> wrote:
>
> K9YC touts the benefits of the 2.4" O.D. Mix #31 Core.
> Anyone know a good source?
> I bought a hand full from Arrow last year, now theirs are on back order.
> Other sites seem pricey.
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2014.0.4716 / Virus Database: 3986/7981 - Release Date: 08/04/14
>

_________________
Topband Reflector Archives - http://www.contesting.com/_topband

[Carl]

I suggest reading the fine print
Ive been buying that part for years and never got a wrong item.

Carl
KM1H



----- Original Message -----
From: "Greg" <n4cc at windstream.net>
To: "'Carl'" <km1h at jeremy.mv.com>; <wb6rse1 at mac.com>; "'Hugh Valentine'"
<hsvdds at juno.com>
Cc: "'Top Band List List'" <topband at contesting.com>
Sent: Tuesday, August 05, 2014 10:46 AM
Subject: RE: Topband: Ferrite Cores


> The Mouser part picture does not look like a FT-240-31. The referenced
> part
> number looks like it fits over a cable.
>
> -----Original Message-----
> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Carl
> Sent: Tuesday, August 05, 2014 7:57 AM
> To: wb6rse1 at mac.com; Hugh Valentine
> Cc: Top Band List List
> Subject: Re: Topband: Ferrite Cores
>
> Hmm, $3 each more than Mouser who also is a very fast shipper, usually
> same
> day.
>
> Mouser Part 623-2631803802
>
> Carl
> KM1H
>
>
> ----- Original Message -----
> From: <wb6rse1 at mac.com>
> To: "Hugh Valentine" <hsvdds at juno.com>
> Cc: "Top Band List List" <topband at contesting.com>
> Sent: Monday, August 04, 2014 10:39 PM
> Subject: Re: Topband: Ferrite Cores
>
>
>> Ships quickly:
>>
>> http://kitsandparts.com/toroids.php
>>
>> Steve WB6RSE
>>
>>
>> On Aug 4, 2014, at 2:54 PM, Hugh Valentine <hsvdds at juno.com> wrote:
>>
>> K9YC touts the benefits of the 2.4" O.D. Mix #31 Core.
>> Anyone know a good source?
>> I bought a hand full from Arrow last year, now theirs are on back order.
>> Other sites seem pricey.
>>
>> _________________
>> Topband Reflector Archives - http://www.contesting.com/_topband
>>
>>
>> -----
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 2014.0.4716 / Virus Database: 3986/7981 - Release Date: 08/04/14
>>
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2014.0.4716 / Virus Database: 3986/7986 - Release Date: 08/05/14
>

[Jim Brown]

On 8/5/2014 7:46 AM, Greg wrote:
> The Mouser part picture does not look like a FT-240-31.

The FT-series of part numbers are PHONY part numbers, dreamed up many
years ago by vendors who have sold them to hams for very high prices.
The ACTUAL part number for a #31 2.4-in o.d. toroid, as defined by
Fair-Rite, the company that MAKES these parts, is 2631803802. You will
find that part number in Appendix One of my tutorial. Kits and Parts is
one of those high price vendors. Amidon may have been the originator of
this scam. Palomar and DXE are in that league as well. They created
these phony baloney numbers so that you wouldn't find the part from a
real industrial vendor at one third the price.

73, Jim K9YC

> The referenced part
> number looks like it fits over a cable.
>
> -----Original Message-----
> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Carl
> Sent: Tuesday, August 05, 2014 7:57 AM
> To:wb6rse1 at mac.com; Hugh Valentine
> Cc: Top Band List List
> Subject: Re: Topband: Ferrite Cores
>
> Hmm, $3 each more than Mouser who also is a very fast shipper, usually same
> day.
>
> Mouser Part 623-2631803802

[Bill Wichers]

I don't think it was entirely a "scam" on the part of Amidon. When you think about it, FT-240-31 is easier to know "Ferrite, Toroid, 2.4" OD material #31" is a lot easier to remember than "2631803802" :-) Similar in concept to using channel numbers for TV instead of frequency assignments -- it makes it easier on the users/viewers.

-Bill

> -----Original Message-----
> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Jim
> Brown
> Sent: Tuesday, August 05, 2014 12:25 PM
> To: topband at contesting.com
> Subject: Re: Topband: Ferrite Cores
>
> On 8/5/2014 7:46 AM, Greg wrote:
> > The Mouser part picture does not look like a FT-240-31.
>
> The FT-series of part numbers are PHONY part numbers, dreamed up many
> years ago by vendors who have sold them to hams for very high prices.
> The ACTUAL part number for a #31 2.4-in o.d. toroid, as defined by Fair-Rite,
> the company that MAKES these parts, is 2631803802. You will find that part
> number in Appendix One of my tutorial. Kits and Parts is one of those high
> price vendors. Amidon may have been the originator of this scam. Palomar
> and DXE are in that league as well. They created these phony baloney
> numbers so that you wouldn't find the part from a real industrial vendor at
> one third the price.
>
> 73, Jim K9YC

[Jim Brown]

On 8/5/2014 11:34 AM, Bill Wichers wrote:
> When you think about it, FT-240-31 is easier to know "Ferrite, Toroid, 2.4" OD material #31" is a lot easier to remember than "2631803802"

Hmmm. The part numbers are in Appendix One of my tutorial, which also
lists known good vendors. Part numbers are also easy to find in
Fair-Rite's excellent on-line catalog. But I guess that someone who is
too mentally lazy to look those up deserves to be ripped off. Just like
someone who doesn't want to be bothered studying the ARRL Handbook or
ARRL Antenna book to learn how antennas work deserves to be ripped off
by those selling "magic" solutions.

73, Jim K9YC

[Chuck Hutton]

Neither do I. It's quite common practice for distributors to have their own part numbers. Witness DigiKey - here is their ferrite page : http://www.digikey.com/product-search/en/inductors-coils-chokes/inductor-ferrite-cores/197937

Yes, Amidon has always seemed a bit high priced. However, I'd like to see some numbers rather than an opinionated post.

Chuck

> From: billw at waveform.net
> To: jim at audiosystemsgroup.com; topband at contesting.com
> Date: Tue, 5 Aug 2014 18:34:39 +0000
> Subject: Re: Topband: Ferrite Cores
>
> I don't think it was entirely a "scam" on the part of Amidon. When you think about it, FT-240-31 is easier to know "Ferrite, Toroid, 2.4" OD material #31" is a lot easier to remember than "2631803802" :-) Similar in concept to using channel numbers for TV instead of frequency assignments -- it makes it easier on the users/viewers.
>
> -Bill
>
> > -----Original Message-----
> > From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Jim
> > Brown
> > Sent: Tuesday, August 05, 2014 12:25 PM
> > To: topband at contesting.com
> > Subject: Re: Topband: Ferrite Cores
> >
> > On 8/5/2014 7:46 AM, Greg wrote:
> > > The Mouser part picture does not look like a FT-240-31.
> >
> > The FT-series of part numbers are PHONY part numbers, dreamed up many
> > years ago by vendors who have sold them to hams for very high prices.
> > The ACTUAL part number for a #31 2.4-in o.d. toroid, as defined by Fair-Rite,
> > the company that MAKES these parts, is 2631803802. You will find that part
> > number in Appendix One of my tutorial. Kits and Parts is one of those high
> > price vendors. Amidon may have been the originator of this scam. Palomar
> > and DXE are in that league as well. They created these phony baloney
> > numbers so that you wouldn't find the part from a real industrial vendor at
> > one third the price.
> >
> > 73, Jim K9YC
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband

[Tom W8JI]

I have seen distributors of core mix cores many times over the years. This
includes distributors on the "only approved list". This is why I always
verify cores I use.

As for Fair Rite being the only legitimate source of part numbers, and
everyone else being a criminal or trying to rip people off,
that's pretty silly. Every place I have worked since 1966 has used internal
house numbers for parts. They didn't do that for any sinister criminal or
immoral motives.

We need to lighten up a little. We sometimes sound like the grumpy
opinionated old men we used to be scared of.


----- Original Message -----
From: "Chuck Hutton" <charlesh3 at msn.com>
To: <topband at contesting.com>
Sent: Tuesday, August 05, 2014 2:51 PM
Subject: Re: Topband: Ferrite Cores


> Neither do I. It's quite common practice for distributors to have their
> own part numbers. Witness DigiKey - here is their ferrite page :
> http://www.digikey.com/product-search/en/inductors-coils-chokes/inductor-ferrite-cores/197937
>
> Yes, Amidon has always seemed a bit high priced. However, I'd like to see
> some numbers rather than an opinionated post.
>
> Chuck
>
>> From: billw at waveform.net
>> To: jim at audiosystemsgroup.com; topband at contesting.com
>> Date: Tue, 5 Aug 2014 18:34:39 +0000
>> Subject: Re: Topband: Ferrite Cores
>>
>> I don't think it was entirely a "scam" on the part of Amidon. When you
>> think about it, FT-240-31 is easier to know "Ferrite, Toroid, 2.4" OD
>> material #31" is a lot easier to remember than "2631803802" :-) Similar
>> in concept to using channel numbers for TV instead of frequency
>> assignments -- it makes it easier on the users/viewers.
>>
>> -Bill
>>
>> > -----Original Message-----
>> > From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Jim
>> > Brown
>> > Sent: Tuesday, August 05, 2014 12:25 PM
>> > To: topband at contesting.com
>> > Subject: Re: Topband: Ferrite Cores
>> >
>> > On 8/5/2014 7:46 AM, Greg wrote:
>> > > The Mouser part picture does not look like a FT-240-31.
>> >
>> > The FT-series of part numbers are PHONY part numbers, dreamed up many
>> > years ago by vendors who have sold them to hams for very high prices.
>> > The ACTUAL part number for a #31 2.4-in o.d. toroid, as defined by
>> > Fair-Rite,
>> > the company that MAKES these parts, is 2631803802. You will find that
>> > part
>> > number in Appendix One of my tutorial. Kits and Parts is one of those
>> > high
>> > price vendors. Amidon may have been the originator of this scam.
>> > Palomar
>> > and DXE are in that league as well. They created these phony baloney
>> > numbers so that you wouldn't find the part from a real industrial
>> > vendor at
>> > one third the price.
>> >
>> > 73, Jim K9YC
>> _________________
>> Topband Reflector Archives - http://www.contesting.com/_topband
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2014.0.4716 / Virus Database: 3986/7985 - Release Date: 08/05/14
>

[Jim Brown]

On 8/5/2014 12:58 PM, Tom W8JI wrote:
> Every place I have worked since 1966 has used internal house numbers
> for parts.

When a customer orders a replacement part from an equipment
manufacturer, there is nearly always a large markup on the part as
compared to the cost of buying the part from the manufacturer of the
part, or from the manufacturer's distributors, and includes the costs of
keeping those parts in stock and selling in single lots.

"House numbers" are also used by manufacturers for custom parts not in
their standard catalog, made custom for a specific user. Examples of
such parts are variable capacitors, mounting brackets, bandswitches,
pots and linear attenuators used in audio gear. Solid state devices may
be sorted for a narrower spec than the standard part and given a house
number.

That's very different from what Amidon and Palomar are doing.

73, Jim K9YC

[Carl]

And the ARRL perpetuates this scam with using Amidon part # in all their
publications.

I still have hundreds of Fair-Rite ferrites and Micrometals powered iron
left over from my Radiokit days and have been selling them off slowly as the
spirit moves me.

No 31 toroids or 73 balun cores.

Carl
KM1H



----- Original Message -----
From: "Jim Brown" <jim at audiosystemsgroup.com>
To: <topband at contesting.com>
Sent: Tuesday, August 05, 2014 12:25 PM
Subject: Re: Topband: Ferrite Cores


> On 8/5/2014 7:46 AM, Greg wrote:
>> The Mouser part picture does not look like a FT-240-31.
>
> The FT-series of part numbers are PHONY part numbers, dreamed up many
> years ago by vendors who have sold them to hams for very high prices. The
> ACTUAL part number for a #31 2.4-in o.d. toroid, as defined by Fair-Rite,
> the company that MAKES these parts, is 2631803802. You will find that
> part number in Appendix One of my tutorial. Kits and Parts is one of
> those high price vendors. Amidon may have been the originator of this
> scam. Palomar and DXE are in that league as well. They created these phony
> baloney numbers so that you wouldn't find the part from a real industrial
> vendor at one third the price.
>
> 73, Jim K9YC
>
>> The referenced part
>> number looks like it fits over a cable.
>>
>> -----Original Message-----
>> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Carl
>> Sent: Tuesday, August 05, 2014 7:57 AM
>> To:wb6rse1 at mac.com; Hugh Valentine
>> Cc: Top Band List List
>> Subject: Re: Topband: Ferrite Cores
>>
>> Hmm, $3 each more than Mouser who also is a very fast shipper, usually
>> same
>> day.
>>
>> Mouser Part 623-2631803802
>
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