Hi Daniele,
Fine! Yes, a nice field to play on. And if a sensitive /p antenna comes
out, this is ideal to coming LF with a nature trip ;-)
73, Stefan
Am 30.08.2011 13:53, schrieb Daniele Tincani:
Hello Stefan,
Thanks a lot for
your feedback.
Yesterday
evening a purchased a bunch of 7 x MU400HH ferrites (10mm x 200mm each)
on eBay, planning to join them together "in parallel" to form a fatter
rod, no idea if it will be a good choice but let's play with this new
toy ;-) Meanwhile I'm collecting ideas and hints from the web about
construction (shielding, computing/measuring parameters, ect.). Projects are stacking as usual :-)
Best regards
Daniele
From:
Stefan Schäfer <[email protected]>
To:
[email protected]
Sent: Tuesday, August
30, 2011 12:34 PM
Subject: Re: LF: Re:
Ferrite wideband antennas?
Hi Daniele,
Could it be possible to tune a ferrite loop over a
frequency range as wide as 100-500KHz? Or at least over the EU NDB band
(say 300-500KHz)?
Any practical suggestion (and/or references on the web)
about how to build it?
I think it is no problem. A narrow band but adjustable antenna is a
good choice. Just use a large variable cap, e.g. 2x500 pF. It may be
helpful to use switched caps and a smaller variable cap like i did. If
you have a high Q antenna, you can then easily fine tune the system.
So maybe 5...100 pF +100 pF+180 pf+270 pF+560 pF or so, depending on
your L.
About the ferrites, there are several sellers on eBay
who offer a russian MU400HH type. Would it be suitable for LF?
Yes, very suitable. I have exactly these types in my LF ferrite antenna
and got a Q of 480. Q will change over the frequency. So maybe it is
even helpful to realise a switched L, for the higher frequencies.
73, Stefan
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