oceanic: Surcouf-Vertical Loop
? oceanic: Surcouf-Vertical Loop
Radio enthusiasts, how does the vertical loop antenna drum work in the Oceanic Surcouf?
Every AM loop antenna I have ever seen always had a horizontally oriented axis.
The reason for this is that AM transmitters generally transmit with a vertical mast, which polarizes the magnetic field into horizontal magnetic field line circles.
I can't help but wonder if French transmitters used a different polarization, perhaps with some other benefit that I am not aware of, like lower noise, better imunity from fading, or rejection of stations with a conventional polarization.
What bands is the drum for?
Regards,
-Joe
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? Its a simple Frame
![Hans M. Knoll](https://www.radiomuseum.org/image.cfm?image=hans_1~~1.jpg&width=120&height=140)
Hello Joe.
Inside of the Box two Frames ar mounted. 1 for LW and 90° shiftet 1 for MW.
Around the Box an single Wire are woundet, to prevent Static Antenna Efffect (shielding)
Here one Sample without screen.
hans
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Clever Loops
Hello Hans,
So these loops were simpler than they seemed. I have seen E-field shields before and they are very effective against a lot of man-made interference, which tends to be electric field disturbance. The loose spiral is a single ended grounded wire.
The crossed loops make very efficient use of space. The stray coupling that is eliminated with the 90o mount helps keep the Q of each loop the highest it can be. This is most useful at the high end of the PO band, where Q is hardest to get.
Another thought comes back from an earlier discussion about shorting inductor turns: When the tuning capacitor is moved from the GO to the PO, the self resonance of the disconnectd GO loop is likely to fall within the PO band at an unpredictable frequency. This would greatly disturb the operation of the PO loop.
Regards,
-Joe
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p.s.: Wave names in French, English and German
GO=Grandes Ondes LW=Long Waves=Langwelle
PO=Petites Ondes MW=Medium Waves=Mittelwelle AM=Amplitude Modulation BC=BroadCast
OC=Ondes Courtes SW=Short Wave KW=Kurzwelle
Note the different wave size appreciation in French vs English or German.
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