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 Runway Beacon Receiver
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 Return to top of page · Post #: 1 · Written at 1:17:36 AM on 16 June 2014.
Art's Gravatar
 Art
 Location: Somewhere, USA
 Member since 22 October 2013
 Member #: 1437
 Postcount: 896

Hi Guys,
I just finished my 359 kHz Amberley airbase runway beacon receiver module compatible with any valve radio Smile
How does it work you don't ask? Well I'll tell you anyway

http://img.photobucket.com/albums/v186/ArtArt/Amberly_zps05093cf3.png.

The output of a 100 kHz crystal oscillator is mixed with the incoming 359 kHz Amberley signal, resulting in 459 kHz.
The 459 kHz signal is close enough to 455 kHz to be detected by the front end valve directly through the antenna, and passed through IF filters to the IF amplifier.

The LO (first half of the tuning gang) can be shorted to disable it, and prevent further heterodyning, or it works to just select a blank section on the dial.

https://www.youtube.com/watch?v=LGaQ2stU6Zc.

Cheers, Art.


 
 Return to top of page · Post #: 2 · Written at 9:23:01 AM on 16 June 2014.
Maven's Gravatar
 Location: Canberra, ACT
 Member since 23 August 2012
 Member #: 1208
 Postcount: 584

Nice work! And has practical application as a cure for insomnia, like an auntie with one green eye reading you an endless bedtime story Smile

Maven


 
 Return to top of page · Post #: 3 · Written at 5:09:09 PM on 18 June 2014.
Art's Gravatar
 Art
 Location: Somewhere, USA
 Member since 22 October 2013
 Member #: 1437
 Postcount: 896

Thanks Maven,
Yes the piratical use of the beacon module isn't so exciting other than to show the radio club,
and have them guess how it was done Smile

I have a 457 kHz crystal here, so when it comes to making one of those low power transmitters
I might as well modulate the audio on that freq, and either short, or bypass the LO,
and send the 457 kHz signal straight through the radio as well.


 
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