Tech

Transmitters for LP AM broadcasting  

 

Deactivated classic transmitters:                                                                                                                            Rohde & Schwarz SK050 (left side  2x)  and  Telefunken S2525/3  (right side)

 

Latest  TX  technology:

                                                                                                    

                

  • Inverted V  antenna  for broadcasting short wave band:

 

 

 

 

L=  20 meter 

 

   

 

  • Inverted L antenna  for broadcasting  medium wave band:

The 1/4 wave inverted L antenna is simple and easy to construct.
The inverted L antenna requires a good buried ground system or elevated radials. The antenna is a form of top-loaded vertical, where the top loading is asymmetrical. This results in both vertical and horizontal polarization.  (Vertical=  21 mtr in lengt  –  Horizontal =  25 mtr in lenght).  Most offshore radio stations, in the 60´s and 70´s, worked  according to this principle.  De vroegere zeezenders werkten vrijwel allemaal met dit soort eenvoudige  kwartgolf draadantennes. Het ´te veel´ aan antennedraad werd eenvoudigweg horizontaal weggespannen.  Met enkel één aanpassingsspoel wordt  de antenne op 50 ohm afgeregeld.

 

 

Audio line for broadcasting  AM:  

Audio-processor:   BW Broadcast DSPX – AM    for the best radio audio performance

AM  audioprocessor

“the  soul of the station sound”

 

 

 

Accurate  AM audio control on negative  & possitive  modulation peaks .

     Mike Radio engineers are frequently  experimenting  to obtain the ultimate sound experience.

Mike Radio mosfet audio power on 5870 AM (screenshot web-sdr in Germany)

 

SDR audio picture: to make audio visible. Made by  Nicolas living near Paris (France) using  ‘Airspy HF’,   freq.  4895 kHz,  on 8th april 2021 around 18.30 UTC (= 20.30 CET local time).

Here below you can hear the audiofile from Nicolas that belongs ‘to the picture’ above:

This is the average reception quality @ the afternoon/evening,  which can be expected on 60 / 52 meter meter band, at a distance like Paris, London, Berlin and  Copenhagen.