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
> <[email protected]> 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