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LF: Re: Power of Donebach 153kHz TX

To: [email protected]
Subject: LF: Re: Power of Donebach 153kHz TX
From: "Walter" <[email protected]>
Date: Sat, 27 Jul 2002 18:06:34 +0200
References: <[email protected]>
Reply-to: [email protected]
Sender: <[email protected]>
Dear Dick and All,
    about DLF. During daylight time normal transmitting power is 500KW from 2 transmitters by Telefunken, each 250KW. These power is fed to the northwestern one of the two masts. The southeastern one is coupled by radiation and has a phase shift. This generates a 3dB attenuation to southeast - because of Radio Brasov, Romania, on the same frequency. During the night power is reduced to 250KW, fed to both masts, also with phase shift. So the attenuation increases to 11dB to protect the Brasov-area. I think you get the full radiation. But probably today is only one transmitter in use because of maintenance. Please try next week again. BTW: The carrier is also modulated in phase shift with GPS-correction-data.
73 Walter DJ2LF
 
 
 
-----Ursprüngliche Nachricht-----
Gesendet: Samstag, 27. Juli 2002 11:03
Betreff: LF: Power of Donebach 153kHz TX

To All from PA0SE,

Sorry to bother you again with a field strength story. But the delete key is within easy reach...

The Deutschlandfunk Donebach transmitter at 153kHz is on again. At 0840 UTC today I measured its field strength as 5.6millivolt/metre.
Using the CCIR groundwave propagation curve that produces plausible results on DCF39 and M0BMU the Effective Monopole Radiated Power (EMRP) comes out as 157kW.

On the Internet I found transmitter power is 500kW. But there are two 363m high aerial masts. This suggests a directive array. As the transmissions are probably not meant for the Netherlands we may get only part of the full blast.

Measuring with the SPM-12 in 25Hz bandwidth the reading moved up and down a bit with the modulation. Perhaps some power (and money) saving controlled carrier system is used. It could also be that some of the lowest modulation frequency components are passed by the 25Hz  I.F. filter. But other BC stations on LF do not show the effect.

73, Dick, PA0SE
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