A Moscow radio amateur sent a review of the “Olusha-10” anti-noise ferrite rod antenna working. He carried out comparative testing twice and made two audio recordings that confirm the ability of this antenna to suppress radio interference in the medium wave frequency range. The comparison was carried out with the standard telescopic antenna of the “Eton E1” radio receiver, an external wire antenna about 15 m long, as well as with the loop and ferrite modules of the German active antenna “GRAHN GS5-SE”.
Mikhail, Moscow (Wed, Aug 08, 2012, 15:03):
We take one of the most powerful radio stations in Moscow:
Frequency: 1044 kHz;
Transmitter power: 40 kW;
Remoteness from the radio transmitter: about 30 km in the direction of radiation;
Radio Receiver: “Eton E1”.
Standard Moscow apartment on the 3rd floor of a reinforced concrete building. The windows into the courtyard in the direction of the radio transmitter, but blocked by the house opposite (it looks like a well). Recently, there has been a very strong interference in the form of “rrrrrr” (hear on the recording), apparently one of the neighbors bought a cheap Chinese dimmer.
So the audio recording:
Mikhail, Moscow (Sat, Aug 18, 2012, 13:54):
I continue to search for a “broad-profile” antenna, in the city it is difficult to pull any wire antenna in full size. I got an interesting exemplar of the once sensational antenna from the German assembler “GRAHN GS5-SE” + plug-in modules. I have just two of modules. If you are interested, I am sending an audio file comparing the reception of the same radio station in extremely difficult urban conditions, there is a very strong interference from household appliances. The frequency of the broadcasting is the same 1044 kHz.
If my hearing serves me right, then your antenna passes less “rrrr”-interference into the useful signal. Yes, with a strong signal from the radio station, “Olusha” shows a maximum of +9..+40, while “GRAHN” can raise the signal according to the signal strength display up to +60..++, you even have to turn on the attenuator. But what’s the point? From such devices, it is precisely high-quality listening to weak radio stations that is required, and not amplification of the signal from a 0.5 MWatt state radio station.
On the other hand, if there is no such interference, then the radio reception is almost the same on both “Olusha” and “GRAHN”. Only the price of devices is very different. Then the question arises, as in advertising: “Why pay more?”.
Active German antenna “GRAHN GS5-SE” is shown in the photo below: