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hanyong
07-08-2007, 08:59
Hello:
I am from Beijing. We test DRM broadcast last week. Now, I describe receive result and what’s problem about it. We hope you talk about it. We receive site nearby one SW station, SW station has very much transmit antennas, these antennas form circularity, diameter is about 1500m. we turn on receiver begin work, we receive good program when far away from antenna,but when we walk in circularity, receiver stop ,we back out circularity ,we receive good program again. Circularity antenna always transmit his program

FritzWue
07-08-2007, 13:16
Probably receiver blocked by too much fieldstrengh when close to the antenna,
signal may then be distorted by the receiver.
Did you try an attenuator at the antenna input?

maxpower
07-08-2007, 20:31
I would agree to Friedrich. Too much power should overload most receivers by far. You could try to power down the transmitter to very low levels and look how that works nearby.

Apart from that I'm thinking about the carrier-feet surpression. At OFDM the wider basis of the multi carriers put together in a way that in sumn it gives a clear signal. I don't know how that works on Circularity antenna direct within the field.

But I would assume the first option.


Greetings,
Stephan