[Fwd: LF: MW]

Frank Gentges metavox at earthlink.net
Thu Dec 16 15:44:24 CST 2004


That, indeed, is the IF frequency.  The lousy design of today's AM 
receivers lets the 453 kHz signal go right into the IF strip to 
interfere with whatever station you tune to.  At least with an external 
antenna.  That is the case with my high end Luxman stereo receiver and a 
Sansui Quadraphonic receiver.

It seems all the hi-fi/stereo/quad stuff has this lousy AM front end 
design.  The lab is in Loudoun county and I have to add an outdoor 
antenna on the roof to get enough signal clear of all the inside 
interference.  Along with the clean AM signal comes this 453 kHz signal. 
  I added a tuned filter on the front end and it fixes the problem.


Alex Fraser wrote:

> Isn't the IF for many AM radios on 455?
> Frank Gentges wrote:
>> It appears there is some operation around 500 kHz. The Germans have 
>> issured a special license for 440 kHz.
>> I note that we have some sort of signal at about 453 kHz.  It seems to 
>> be a data signal with bursts of data each second.  On the minute, the 
>> signal sounds different suggesting less data is sent on the minute.
>> I don't remember hearing this signal during our LF work.  It is now 
>> interfering with the lousy front end in my low tech AM radio at our 
>> lab and I have added a front end filter to get rid of it.
>> Anyone know what this new signal is?
>> Frank K0BRA
>> ------------------------------------------------------------------------
>> Subject:
>> LF: MW
>> From:
>> "Walter Staubach" <walter.staubach at fen-net.de>
>> Date:
>> Thu, 16 Dec 2004 17:52:13 +0100
>> To:
>> "RSGB LF" <rsgb_lf_group at blacksheep.org>
>> To:
>> "RSGB LF" <rsgb_lf_group at blacksheep.org>
>> Good News for 2005
>> Dear friends,
>>         last week I got a permission to operate a MW-transmitter from 
>> the German RegTP (Regulierungsbehörde für Telekommunikation und Post). 
>> It will be used for studies of progagation and testing modern 
>> receiving modes.
>> Some data:
>> Frequency 440KHz, bandwidth 200Hz, max. 9W ERP
>> Call DI2AG (the DI-prefixes are for test and research only, therefore 
>> this is no hamradio application).
>> Modes A1A, A1B, F1B, G1B. Location JN59NO.
>> The permission is valid in 2005.
>> The TX will be operated as a beacon, QRSS3 prefered, with a text like 
>> "DI2AG JN59NO 1W". This will be repeated in normal CW.
>> I would be glad to receive your reports like date / time from - to / 
>> report in uV/m or dB below noise or similar / remarks / by e-mail. 
>> Screenshots appreciated.
>> The QRSS-frequency will be 440.044Khz, I hope there will not be other 
>> lines. Please send your mails to walter.staubach at fen-net.de 
>> <mailto:walter.staubach at fen-net.de> or dj2lf at darc.de 
>> <mailto:dj2lf at darc.de>     I`ll try to get di2ag at fen-net.de 
>> <mailto:di2ag at fen-net.de> , too.
>> Please prepare your equipment for 440KHz. At 1.1.05   00.01MEZ the big 
>> switch will be turned from red to green.
>> I´ll keep you informed.
>> 73   Walter  DJ2LF
>> ------------------------------------------------------------------------
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