Re: Reliable but reasonably priced sources of ferrite for FSLs?-FARMERIK


Gary DeBock
 

<<<    Hi Gary,
I'm poking at you!
You have the smaller FSL's to use in a comparison test.
The crystal radio guys love this material because of the
high Q's they get with it.
Maybe mkmak222 would give you a deal on enough ferrites to build a
small FSL to do the test, if R40C1 proved better, it would be great for
his sales.

                             Mikek   >>>

Hi Mikek,

Thanks for the link, and the new R40C1 material does seem very interesting. I have been a regular Litz wire customer of Mkmak222 for about 10 years, and know him to be honest and reliable.

The main problem with this 200mm x 10mm ferrite rod is the price. At $14.00 shipped, the cost would be reasonable for loopstick construction, but pretty impractical for FSL's. The 200mm x 10mm rod size is one of the standard Russian surplus rod sizes, and many FSL's have been constructed here with that rod size. In fact, one of the test models in the 2012 FSL design article was a 3.5" Long Rod model, using 23 of the 200mm x 10mm ferrite rods. At the cost of $14 per rod (shipped) for the new R40C1 ferrite material, the construction cost of such a miniature FSL would be $322 even before the Litz wire, variable cap and PVC frame cost (which would raise it up to around $450). Even if such an expensive miniature FSL is built, almost nobody would be interested in duplicating it.

For loopsticks, though, it would be a completely different matter. $14 is a very reasonable cost for a high quality ferrite rod of that size, and there are already excellent loopstick designs popular in the DXing community for both MW and LW (such as at  http://www.mediafire.com/file/du3sr5cd9thqvau/7.5inch-LS-PL380.doc/file
Since there are already several PL-380 and XHDATA D-808 models here with that 7.5" loopstick design, it would be easy to substitute the R40C1 material for the Amidon Type 61 ferrite rod, and compare the relative performance on MW and LW. I'll probably order a few of the new R40C1 rods for such a test in the next few days, and then let the group know how everything shakes out.

73, Gary

  
  


-----Original Message-----
From: lamontcranston17 <nojunk@...>
To: main <main@UltralightDX.groups.io>
Sent: Tue, Feb 5, 2019 6:47 am
Subject: Re: [UltralightDX] Reliable but reasonably priced sources of ferrite for FSLs?-FARMERIK

In response to Gary's 2012 length to diameter conclusions,
there is another characteristic, I haven't found any information on.
That would be, how permeability affects the FSL.
I see R40C1 material has a ui of 40 vs 400 for the material
used in Gary's initial testing.
 I would like to see a shootout of identical size FSL's
that use the two different 40 vs 400 ui materials.

Hi Gary,
I'm poking at you!
You have the smaller FSL's to use in a comparison test.
The crystal radio guys love this material because of the
high Q's they get with it.

Maybe mkmak222 would give you a deal on enough ferrites to build a
small FSL to do the test, if R40C1 proved better, it would be great for
his sales.


                             Mikek



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