Hi again, Carl
Unfortunately, there are a few pages out there that I do not wish to be on,
including some that say that everything has already been figured out, and
there is nothing new that will ever happen on 160. There are some
persuasive reasons to be thinking outside of this 80 year old box that 160
meters has been in.
To be really truthful, I have finally settled on a suspicious view of
nearly everything 160 meters. It has been remarkably useful to ask the
question "What if they are simply wrong, or there are substantial errors?"
I will keep my own counsel, AND all the other published lists beside the
one published by Micrometals. It's a free country and you are certainly
entitled to your viewpoints.
Good Luck and 73, Guy.
On Fri, Dec 16, 2011 at 11:14 AM, ZR <zr@jeremy.mv.com> wrote:
> **
> As I said earlier it always pays to go to the manufacturers data first
> before relying upon and posting erroneous information. Micrometals explains
> the caveats for deviating outside of the basic frequency ranges.
>
> Try this and scroll to Radio Frequency Properties
> http://www.micrometals.com/materials_index.html
>
> BTW Mix 8 does not replace 6. However 7 was developed as the alternative
> to be more temperature stable in use for VFO's and other critical circuits
> thus the small diameters available.
>
> Note also that Mix 0 is just that, there is no iron powder, its just a
> phenolic donut and comes in handy at UHF
>
> Free software is also available to take the guesswork out especially when
> discussions get a bit confusing..
> http://www.micrometals.com/software_index.html
>
> We should all strive to be on the same page
>
> Carl
> KM1H
>
>
> ----- Original Message -----
> *From:* Guy Olinger K2AV <olinger@bellsouth.net>
> *To:* ZR <zr@jeremy.mv.com>
> *Cc:* richard@karlquist.com ; topband@contesting.com ;
> Martin<hamradio@vr-web.de>
> *Sent:* Thursday, December 15, 2011 11:43 PM
> *Subject:* Re: Topband: T-200 vs. T-300
>
> #2 powdered iron at mu of 10 is the lowest mu of the powdered iron types
> listed with a frequency range that covers 160 meters (in some lists #2 is
> 2-30). You can rest assured Jerry Sevick had the list below. In his 160
> meter comparison with #2 material, he tested 1,3,15 and 26. Number 6 really
> doesn't work under 10 MHz, as specified in other lists. It's a "replaced"
> mix that has had problems. Here's a composite list of powdered iron
> materials from various incomplete sources.
>
> 0 Mix (Tan) 100-300 MHz u=1
> 1 Mix (Blue) 0.5-5 Mhz u=20
> *2 Mix* (Red) 1-30 MHz, high volume resist. u=10 [Alt list 2-30 Mhz]
> 3 Mix (Gray) .05-.5 MHz, u=35
> *6 Mix* (Yellow) 1-50 MHz, similar to mix #2. u=8 [alt list 10-50 MHz,
> alt list use #8]
> 7 Mix 3-35 MHz, u=9 small cores only
> *8 Mix *(Yellow / Red) 1-50 MHz, replaces 6 mix. u=35
> 10 Mix 30-100 MHz, u=6
> 12 Mix 50-200 MHz, u=4
> 15 Mix 0.1-2 MHz, u=25
> *17 Mix* (Blue/Yellow) 50-200 MHz, good Q. u=3 [alt list u=4]
> *18 Mix* (Green/Red) u=55, Low Core Loss, Similar to 8 Mix
> *26 Mix* (Yellow/White) DC-800 KHz, great 60 Hz.
> EMI range. Line 'em up on speakers / AC wires u=75
> *40 Mix* (Green/Yellow) Power conversion similar to mix 26
> *52 Mix* (Green/Blue) DC-1 MHz, high perm. u=75
>
> 73, Guy.
>
> On Thu, Dec 15, 2011 at 10:50 PM, ZR <zr@jeremy.mv.com> wrote:
>
>>
>> ----- Original Message ----- From: "Guy Olinger K2AV" <
>> olinger@bellsouth.net>
>> To: <richard@karlquist.com>
>> Cc: <topband@contesting.com>; "Martin" <hamradio@vr-web.de>
>> Sent: Thursday, December 15, 2011 10:05 PM
>>
>> Subject: Re: Topband: T-200 vs. T-300
>>
>>
>> Hi Rick,
>>>
>>> No magic. Just the right stuff, for the FCP, anyway.
>>>
>>> To your particulars, when Jerry Sevick measured various ferrites, he
>>> measured the lowest loss at mu=40. This was very low, as was the #2
>>> powdered iron at mu=10, the lowest of the powdered iron formulas.
>>>
>>
>> Since when is a 2 mix the lowest mu? It is ideal for QRO and HF since 6
>> and 7 mix arent made in QRO sizes and arent suitable at 160 anyway.
>>
>> Carl
>> KM1H
>>
>>
>>
>>
>> So use
>>
>>> of ferrites introduces a significantly reduced number of turns, with a
>>> much
>>> more coarse granularity of possible inductive values, that has to be
>>> worked
>>> out to use with the FCP, AND the behavior of the mu=40 core under highly
>>> reactive loads is not spec'd by the manufacturer. The ferrite will have
>>> far
>>> less radiating surface if it does heat up under extreme reactive load,
>>> AND
>>> the length of the parallel bifilar wires may not be enough to cover 160
>>> with the needed behavior in this app.
>>>
>>> But my admonition about no ferrites has more to do with my knowing that
>>> people have misc T240 and T200 form factor ferrites of ALL KINDS laying
>>> around, and want to use the one they just found down in the junk box,
>>> which
>>> does NOT have the material # or mu marked on it anywhere. And these
>>> requests seem to pop up just before a contest, when most hope of getting
>>> the correct stuff before contest has gone by the wayside. You will note
>>> that I have pounded in Amidon T300A-2 #2 powdered iron toroid or strict
>>> equivalent, over and over again. And I get back "please, please, please
>>> tell me that I can use my junkbox ferrite toroid". But don't hold your
>>> breath. In over four years of working with non-resonant antenna
>>> solutions
>>> on 160, **NONE** of the ferrites we tried to use made it. We burnt or
>>> cracked ALL of them at QRO. ALL of them. Really. Ferrite demolition
>>> derby.
>>>
>>> I have a new collection of #31 ferrite stuff, but I use those in low band
>>> RFI suppression, not transformers. So I'm NOT going to tell anyone it's
>>> OK
>>> to use a ferrite toroid for feeding an FCP.
>>>
>>> Beyond that, what is NOT in doubt is that the #2 powdered iron choice
>>> works
>>> and works well. The installations where I have been able to run QRO
>>> brick
>>> on key and quick go check toroid temp have all been stone cold. Anyone
>>> has
>>> contrary experience please let us know ASAP. We will certainly want to
>>> investigate and determine why in one place and why not in another.
>>>
>>> As to why he made his #2 powdered iron choice, Jerry Sevick W2FMI, covers
>>> this convincingly in his book, pages 58-63, which I will NOT try to
>>> reproduce on the reflector, as even if I did, I can't pass along the
>>> essential graphs, photos and diagrams. ("Understanding, Building, and
>>> Using Baluns and Ununs -- Theory and Practical Designs for the
>>> Experimenter", Jerry Sevick W2FMI, Copyright 2003, CQ Communications,
>>> Inc.,
>>> Hicksville, New York)
>>>
>>> I have found, over the time that I have been working on top-band issues,
>>> that dropping back after blowing something up and consulting W2FMI or his
>>> material has been most valuable.
>>>
>>> Alas, Jerry is a silent key, and I can no longer phone him to further
>>> expound upon his choices. He particularly chose the large #2 powdered
>>> iron
>>> cores for applications with a lot of stress on the core, particularly 160
>>> meters. Some key quotes:
>>>
>>> "Because my simple loss measurements indicated that the higher
>>> permeability
>>> powdered-irons had more loss than the No. 2 material, I decided to
>>> design a
>>> 4:1 Ruthroff Balun using this material--but with a larger core and more
>>> turns than the McCoy Balun. Although McCoy's design has enjoyed
>>> considerable success over the years, I felt that a larger inductive
>>> reactance was desirable in order to assure better performance on the
>>> lower
>>> frequency bands (particularly 160 meters). [Ibid p.59]
>>>
>>> "I knew ... that loss with ferrite materials was related to the voltage
>>> drop along the length of the [bifilar winding] and to the ...
>>> permeability.
>>> Permeabilities of 40 (No. 67 Ferrite) exhibited the lowest loss. ...
>>> powdered iron #2 material with a permeability of 10 also showed the very
>>> same low loss. Because powdered-iron material has been known to be more
>>> rugged and linear than ferrite material, this suggested that other
>>> powdered-irons ... should be investigated. ... However all four materials
>>> showed a definite lower input impedance than #2 material, ..." [Ibid
>>> p.59]
>>>
>>> Sevick had access to all of the ferrites, but did not choose any of them
>>> for his monster hang-on-the-back-of-the-tuner 4:1 Balun, especially
>>> intended to deal with wild voltages, very reactive loads, etc, and handle
>>> them as well on 160 as 80-10. Instead Sevick chose the T400A-2 and #2
>>> powdered iron to lay out there as his personal method. So we've done the
>>> same. And everywhere we've used teflon-sleeved #14 double polyimide on
>>> the
>>> #2 powdered iron cores, bad stuff has just quit happening, they work, and
>>> they run stone cold.
>>>
>>> At various scattered places in the book Sevick talks about all the issues
>>> that come to bear on designing an isolation transformer on 160 meters. I
>>> may not be able to develop a federal level proof case satisfactory so
>>> some,
>>> but I am sticking with Mr. Sevick. His guidance has always panned out and
>>> explained what was ailing. He did his high-stress 160 meter windings on
>>> large #2 powdered iron toroids after research. So are we. We have the
>>> hard-won results that prove out Sevick's and our choices.
>>>
>>> 73, Guy.
>>>
>>> On Thu, Dec 15, 2011 at 2:58 PM, Rick Karlquist <richard@karlquist.com
>>> >wrote:
>>>
>>> Guy Olinger K2AV wrote:
>>>>
>>>> > Martin has the right instincts, says it feels fishy for this. But
>>>> it's
>>>> > worse than he thinks. And don't even consider using ferrites.
>>>> >
>>>> > The T300A-2 core and 20 bifilar turns were SPECIFICALLY chosen to >
>>>> produce
>>>> > a
>>>> > residual inductance value in the right order of magnitude to cancel a
>>>> > typical residual capacitive reactance from a 160 meter 5/16 wave
>>>> single
>>>> > wire folded counterpoise, AND provide enough coupling to make the
>>>> > transformer work, AND maintain a low enough loss to operate QRO
>>>> without
>>>> > heating, or especially to operate QRP without further handicapping the
>>>> > operator with needless loss. This allows the builder of the "simple
>>>> > solution" to prune the wire to get resonance and remain somewhere >
>>>> around
>>>>
>>>> I'm trying to understand here what is magic about powdered iron.
>>>>
>>>> It is true you can't just use any random piece of ferrite.
>>>> But if the T300A-2 were replaced with LOW PERMEABILITY ferrite
>>>> having the same permeability as a T300A-2 core, it would produce
>>>> the required residual inductance. The loss of low permeability
>>>> ferrite is extremely low, probably lower than powdered iron.
>>>> Coupling is a function of how the turns are wound, not the core
>>>> material.
>>>>
>>>> Am I missing something?
>>>>
>>>> Rick N6RK
>>>>
>>>>
>>>>
>>>>
>>>> ______________________________**_________________
>>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>>
>>>
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>>>
>>
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