Re: [A-DX] Log: Energy Power AM, Dublin, 1395 kHz, 22.04.12, 02.20 UT, SIO 232

[Christoph Ratzer <ratzer@xxxxxxxxx>]

> heute morgen konnte ich wieder was schönes auf der Mittelwelle finden: Energy Power AM 1395 aus Dublin. 

Und heute bestätigte mir John Power den Empfang via energypoweram@xxxxxxxxxxx

Hier ein Auszug seines Schreibens:

The station started in 2003 as an engineering experiment to build
a totally solid state AM transmitter. It has traditionally been a 
problem even in low power AM transmitters obtaining modulation 
transformers, audio amplifiers etc so the project was set out to design 
a direct coupled high efficiency transistor design. 

The power decided for a few reasons was to be 300 watts as it was felt 
this would provide a resonable signal over the
area we intended to cover while not costing too much on electricity
to run. Also at this moderate level, the chances of interference with
other telecommunications services would be reduced. 

So the design is 300 Watts using a Class D RF amplifier and
series modulated with an integral Class S modulator utilising Pulse
Width Modulation.

If you google energypoweram, you will find a web site in Finland
that has photographs of some of the equipment.

The TX feeds a 1/8 wavelength antenna tuned to 1395KHz
which is a Tee shape with a 30 metre top hat and a 15 metre
vertical section. The antenna is brought to resonance using
a top loading coil just under the top hat. This method of loading
improves the gain of the electrically short antenna. This
antenna sits over a 20 radial earth system acting as the ground
return.

The Audio feed at just line level is fed from an Orban 9100A
vintage processor that is fed in turn from the PC sound card.




73 Christoph

--  
http://remotedx.wordpress.com








--
-----------------------------------------------------------------------
Diese Mail wurde ueber die A-DX Mailing-Liste gesendet.
Admin: Christoph Ratzer, OE2CRM  http://www.ratzer.at
-----------------------------------------------------------------------
Private Verwendung der A-DX Meldungen fuer Hobbyzwecke ist gestattet, jede
kommerzielle Verwendung bedarf der Zustimmung des A-DX Listenbetreibers.