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From: Dimitrios Tsifakis <dtsifakis@gmail.com>
Date: Sun, 13 Jan 2019 07:02:52 +1100
Message-ID: <CAKvcm2e8uxWOAH5AfRdWqW9kiQ=2DaboOH4V3v2hBujxnZF=Ug@mail.gmail.com>
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Re: a lot of ferrite
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Hi Roman,

thanks for the links, I would have never found them through a search
engine as I don't speak russian. Looks like an interesting discussion,
I will certainly have a read. To my surprise, the automatic
translation does a reasonably good job!

73, Dimitris VK2COW

Στις Κυρ, 13 Ιαν 2019 στις 4:01 π.μ., ο/η Roman <rw3adb@yandex.ru> έγραψε:
>
> Hello Dimitris!
>
> A lot of interesting info about ferrite rod ants and results, but on Russian language:
>
> http://136.su/index.php/topic,119.0.html
>
> Use translator babelfish or other and use links and schematics.
>
> At once - UA3AGC from Minussinsk, East Siberia NO66, nr Krasnoyarsk was received in DM4TR location JO61de - QRB ~5000 km! - and VO1NA also too!
>
> UA3AGC DE DM4TR
> http://136.su/index.php/topic,18.msg7095.html#msg7095
> http://136.su/index.php/topic,119.msg7099.html#msg7099
>
> VO1NA DE DM4TR
> http://136.su/index.php/topic,119.msg13881.html#msg13881
>
> The ferrite rod ant was used on DM4TR grabber in great QRM from local MW broadcast situated in near QTH - ~ 900m!
> The great RX reports was in that situation!
>
> The other great forum topic and results will be interesting for you on the other russian forum:
>
> http://www.radioscanner.ru/forum/topic22993.html
>
> 73!
> Roman, RW3ADB
>
> > Minor correction, the calculated relative permeability should be about
> > 500, I made a mistake in the initial calculation. I just discover why
> > they call it initial permeability (bad joke) :-)
> >
> > 73, Dimitris VK2COW
> >
> > Στις Σάβ, 12 Ιαν 2019 στις 2:48 μ.μ., ο/η Dimitrios Tsifakis
> > <dtsifakis@gmail.com> έγραψε:
> >
> >> Hi LF group,
> >>
> >> I have managed to acquire a few very large ferrite rods (36 cm x 10 cm
> >> x 2 cm). The material is unknown but I managed to form a square
> >> 'toroid' with four of them (they are heavy so gravity was enough to
> >> keep everything in place for a measurement) and I measured about 15 uH
> >> for 4 turns at 0.1 MHz, which if I have done the calculations
> >> correctly implies a relative permeability of about 1000.
> >>
> >> The R of the impedance of the square loop was low (<0.2 ohm) at 0.1
> >> MHz and it increased fast with frequency (170 ohm at 5 MHz!).
> >>
> >> The question is, what LF/VLF experiment would you do if you had half a
> >> dozen of these rods?
> >>
> >> 73, Dimitris VK2COW
> --
> 73!
> Roman, RW3ADB
>