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LF: Update on Akraberg 531

To: <[email protected]>
Subject: LF: Update on Akraberg 531
From: John Pumford-Green <[email protected]>
Date: Sat, 30 Aug 2008 10:28:54 +0100
Organization: The Gammy Bird
Reply-to: [email protected]
Sender: [email protected]
Hello LF,

I had several email exchanges yesterday with the engineers and other
staff at Utvarp Foroya, Faroe Telecom and Thomson. They acknowledge a
problem and are working to correct it.


>From the broadcaster :-

====================================================================

Thank you very much for drawing our attention to the problems that the
new Medium Wave transmitter at Akraberg is causing, and for your
detailed and very informative report on the problem. 

The transmitter is a 50/100kW replacement for the old 200kW
transmitter, which went of air some months ago. 

It is used by Kringvarp Foroya (The Faroese Broadcasting Co.), it is
owned by the Faroese Government, and it is maintained by Faroese
Telecom. 

Faroese Telecom is aware of the problem, and is working with the
manufacturer, Thomson, to solve the problem. 

They hope to solve the problem in the coming week. 

Best regards Carsten M. Arnskov 
Kringvarp Føroya (The Faroese Broadcasting Co.)

===================================================================



The lastest news came from a Faroes Telecom engineer:-

===========================================================
Hi John Pumford-Green
 
We are trying to solve the problem with the transmitter vendor
(Thomson).
We have reduced modulation from -3 dB to -6 dB and reduced the output
power by 3 dB.
We have also moved from a 10 kHz to a 4.7 kHz audio filter.
 
Best regards
 
Jóhan P. Poulsen
Faroese Telecom

==============================================================


The signal is now much cleaner, but they've had to take drastic steps
to do it, leading to very low mod depths (30-40% only!) and a rather
muddy sounding signal.

I'm amazed that they'll admit to a baseband filter of 10kHz having been
used at first.

I can still detect faintly a raising of the noise floor down at 500kHz
when the modulation is at a relatively high level, the grabber shows
this slight effect only when there's a distinct change in program
material between silent and "loud", although it seems a bit less
obvious this morning so perhaps they've done something else to reduce
the out of band noise radiation.

Hope this is ON TOPIC enough ;-)


Regards,

John P-G
GM4SLV



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